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Pain perception in chronic pain patients : a signal detection analysis 1991

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PAIN PERCEPTION IN CHRONIC PAIN PATIENTS: A SIGNAL DETECTION ANALYSIS by MARY LEONA MAHON B.Sc., The U n i v e r s i t y o± A l b e r t a , 1982 M.A., The U n i v e r s i t y ot B r i t i s h C o l u m b i a , 1986 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY THE FACULTY OF GRADUATE STUDIES ( P s vc ho 1og y) We a c c e p t t h i s t h e s i s as c o n f o r m i n g to the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA J u l y 1991 @ Mary Leona Mahon, 1991 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada DE-6 (2/88) ABSTRACT T h e p u r p o s e o t t h i s i n v e s t i g a t i o n was t o e x a m i n e t h e s u p p o s i t i o n t h a t c h r o n i c p a i n p a t i e n t s ( C P P s ) h a v e a l t e r e d p a i n p e r c e p t i o n . Two m o d e l s w e r e e x a m i n e d t h a t l e d t o o p p o s i n g p r e d i c t i o n s a s t o how C P P s w o u l d r e s p o n d t o p a i n t u l s t i m u l i ( i . e . , t h e h y p e r v i g i l a n c e a n d a d a p t a t i o n - l e v e l m o d e l s ) . B o t h p r e d i c t i o n s h a v e b e e n s u p p o r t e d bv p a s t r e s e a r c h b u t b e c a u s e o t m e t h o d o l o g i c a l v a r i a t i o n a n d t h e t v p e o i p a i n d i s o r d e r s t u d i e d , i t h a s r e m a i n e d u n c l e a r u n d e r w hat c i r c u m s t a n c e s t h e p r e d i c t i o n s o t t h e s e two m o d e l s mav be met. T h e r e s p o n s e s o i p a i n p a t i e n t s t o p a i n t u l s t i m u l i h a v e b e e n t o u n d t o v a r y t o r p a t i e n t s - w i t h d i t t e r e n t c l i n i c a l p r e s e n t a t i o n s ( i . e . , t h o s e w i t h a n d w i t h o u t m e d i c a l l v i n c o n g r u e n t s i g n s a n d symptoms'). T h e r e i o r e , t h e p r e s e n t i n v e s t i g a t i o n s o u g h t t o c o m p a r e t h e r e s p o n s e s t o r a d i a n t h e a t s t i m u l i o t s i x t y C P P s ( t h i r t y w i t h a n d t h i r t y w i t h o u t a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n ) t o t h i r t v a g e a n d s e x m a t c h e d n o r m a l c o n t r o l s u b j e c t s ( i . e . , p a i n - t r e e i n d i v i d u a l s ) . S i g n a l d e t e c t i o n t h e o r y m e t h o d o l o g v was u s e d i n o r d e r t o s e p a r a t e l y e v a l u a t e s e n s o r y s e n s i t i v i t v a n d t h e r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s a s p a i n t u l . I n a d d i t i o n , c o g n i t i v e a n d a t i e c t i v e i a c t o r s w e r e a s s e s s e d i n o r d e r t o i d e n t i i v p o t e n t i a l p s y c h o l o g i c a l c o r r e l a t e s o t a l t e r e d p a i n p e r c e p t i o n . T h e r e s u l t s o t t h i s s t u d y i n d i c a t e d t h a t t h e p r e s e n c e o t a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n d i s t i n g u i s h e d p a t i e n t s on t h e i r s u b j e c t i v e r e p o r t o t d i s a b i l i t v a n d t o a l e s s e r e x t e n t c o g n i t i v e a p p r a i s a l a n d a t i e c t i v e d i s t r e s s r e g a r d i n g t h e i r p a i n c o n d i t i o n . They d i d not d i t t e r i n t h e i r e s p o n s e s t o p a i n t u l s t i m u l i . In a p o s t hoc a n a i v s i s where CPPs were c l a s s i t i e d i n t o ' o r g a n i c ' and ' t u n c t i o n a i 1 d i a g n o s t i c g r o u p s , s i g n i i i c a n t d i t t e r e n c e s i n p a i n t h r e s h o l d and the r e s p o n s e b i a s to r e p o r t p a i n were i o u n d . P a t i e n t s c l a s s i t i e d as ' o r g a n i c ' had s i g ni±icant 1v h i g h e r p a i n t h r e s h o l d s compared to normal c o n t r o l s u b j e c t s and p a t i e n t s c l a s s i i i e d as ' t u n c t i o n a i ' . D i t t e r e n c e s i n p a i n t h r e s h o l d were p r i m a r i l v r e p r e s e n t e d by the r e s p o n s e ' b i a s to r e p o r t s e n s a t i o n s as p a i n t u l r a t h e r t h a n s e n s o r y s e n s i t i v i t v t o the s t i m u l i . The ' t u n c t i o n a i ' g r o u p had a s l i g h t l y l o w e r p a i n t h r e s h o l d t h a n the normal c o n t r o l group but t h i s d i t t e r e n c e was not s i g n i t i c a n t . The r e s u l t s a r e d i s c u s s e d i n l i g h t ot the two models ot p a i n p e r c e p t i o n . The two methods used t o c l a s s i t v p a i n p a t i e n t s a r e d i s c u s s e d a c c o r d i n g to t h e i r o r t h o g o n a l c h a r a c t e r i s t i c s on s e n s o r y , c o g n i t i v e , and a t i e c t i v e components. / i v TABLE OF CONTENTS P a g e A b s t r a c t i i L i s t of T a b l e s v i Acknowledgements v i i i INTRODUCTION 1 LITERATURE REVIEW The H y p e r v i g i l a n c e Model 6 The A d a p t a t i o n - 1 e v e 1 Model 8 S i g n a l D e t e c t i o n T h e o r y IU R e s e a r c h on P a i n P e r c e p t i o n i n C h r o n i c P a i n P a t i e n t s 18 S i g n a l D e t e c t i o n T heory S t u d i e s 18 O t h e r I n v e s t i g a t i o n s 21 A n a l y s i s ot R e s e a r c h on P a i n P e r c e p t i o n i n C h r o n i c P a i n P a t i e n t s 2 3 Type ot P a i n S t i m u l u s Used 23 D i t t e r e n c e s i n Type ot P a i n D i s o r d e r S t u d i e d 25 C 1 a s s i t i c a t i o n ot P a i n P a t i e n t s 28 M e d i c a l I n c o n g r u i t y C 1 a s s i t i c a t i o n 32 Summary and P u r p o s e ot the P r e s e n t Study 37 H y p o t h e s e s and D e s i g n 39 METHOD S u b j e c t s 42 Group A s s i g n m e n t 46 Eq u i pmen t 4 9 S t i m u l i 49 P r o c e d u r e 5 1 S i g n a l D e t e c t i o n T h e o r y Measures ot D i s c r i m i n a b i 1 i t y and Response B i a s 53 Measures ot Impairment and D i s a b i l i t y 55 S e l t - R e p o r t M e a s u r e s 57 S t a t i s t i c a l A n a l y s i s 60 RESULTS A n a l y s i s ot Demographic V a r i a b l e s 63 A n a l y s i s ot P a t i e n t C h a r a c t e r i s t i c s 64 A n a l y s i s o i Dependent Measures 68 Group D i t t e r e n c e s : P a i n Measures 68 R e l a t i o n s h i p s Among the P a i n M e asures 73 Group D i t t e r e n c e s : C o g n i t i v e Measures 75 R e l a t i o n s h i p s Among the C o g n i t i v e M e a s u r e s 78 Group D i f f e r e n c e s : A f f e c t i v e M e a sures 7 9 R e l a t i o n s h i p s Among the A f f e c t i v e M e a s u r e s 80 V A d d i t i o n a l C o r r e l a t i o n a l A n a l y s e s 8 i R e l a t i o n s h i p s Among the Dependent Measures 81 R e l a t i o n s h i p s Among the Dependent Measures and Measures of S e v e r i t y and Symptoms P r e s e n t a t i o n 83 P o s t Hoc A n a l y s e s 86 Group D i f f e r e n c e s : P a i n Measures 90 Group D i f f e r e n c e s : C o g n i t i v e Measures 92 Group D i f f e r e n c e s : A f f e c t i v e Measures 92 Group D i f f e r e n c e s : M e d i c a l l y I n c o n g r u e n t Symptoms 92 Summary of F i n d i n g s 96 DISCUSSION P a i n P e r c e p t i o n i n C h r o n i c P a i n P a t i e n t s 100 M e d i c a l l y I n c o n g r u e n t Symptom P r e s e n t a t i o n , D i s a b i l i t y , and D i s t r e s s 108 The R o l e of C o g n i t i o n and A n x i e t y i n the E x p e r i e n c e of P a i n 115 Gender D i f f e r e n c e s i n the E x p e r i e n c e of P a i n 116 Summary and C o n c l u s i o n s 119 REFERENCES 12 4 APPENDICES App e n d i x A . N o n o r g a n i c P h y s i c a l S i g n s 135 A p p e n d i x B . The P a i n D r a wing and S c o r i n g C r i t e r i a 136 A p p e n d i x c. I n a p p r o p r i a t e Symptom I n v e n t o r y 1 38 Append i x D . C o n s e n t Form f o r P i l o t Study S u b j e c t s 139 A p p e n d i x E - C o n s e n t Form f o r C h r o n i c P a i n S u b j e c t s 140 A p p e n d i x F . I n s t r u c t i o n s f o r P a i n P e r c e p t i o n Task. 142 A p p e n d i x G. Data Sheet f o r S i g n a l D e t e c t i o n Task 144 A p p e n d i x H . D e b r i e f i n g of P a r t i c i p a n t s 145 A p p e n d i x I . C o n s e n t Form f o r C o n t r o l S u b j e c t s 1 46 A p p e n d i x J . P h y s i c a l Impairment Index 148 A p p e n d i x K . O s w e s t r y Low Back P a i n D i s a b i l i t y Q u e s t i o n n a i r e 149 A p p e n d i x L . G r a c e l y R a t i n g S c a l e s and S c o r i n g 15 1 A p p e n d i x M. C o p i n g S t r a t e g y Q u e s t i o n n a i r e 153 A p p e n d i x N . P a i n E x p e r i e n c e S c a l e 156 A p p e n d i x 0 . T r a i t A n x i e t y I n v e n t o r y 159 v i L IST OF TABLES T a b l e 1 . T a b l e 2. T a b l e 3. D e c i s i o n a l M a t r i x t o r B i n a r y SDT T a a I'. Papc 1 2 P e r c e n t a g e ot M e d i c a t i o n Use by P a t i e n t Group 45 P e r c e n t a g e Breakdown ot D i a g n o s e s i n the P a t i e n t Samole T a b l e 4. R e l a t i o n s h i p s Among Measures ot I n c o n g r u e n t P a i n T a b l e 5. T a b l e 6. T a b l e 7. T a b l e 8. T a b l e 9. T a b l e 10. T a b l e 1 1 . T a b l e 12. T a b l e 13. T a b l e 14. T a b l e 15. T a b l e 16. T a b l e 17. P e r c e n t a g e O c c u r r e n c e ot C r i t e r i a W i t h i n the I n c o n g r u e n t Group P e r c e n t a g e ot P a t i e n t s M e e t i n g I n c o n g r u e n t C r i t e r i a C o r r e l a t i o n s Among Measures ot P h v s i c a l L i m i t a t i o n and I n c o n g r u e n t S i g n s Means and S t a n d a r d D e v i a t i o n s t o r P a i n Measure s MANOVA Summary T a b l e t o r P a i n M e a s u r e s w i t h P a i n P a t i e n t s P o o l e d U n i v a r i a t e A n a l y s e s : P a i n M e a s u r e s w i t h P a i n P a t i e n t s P o o l e d MANOVA Summary T a b l e t o r P a i n M e asures w i t h P a i n P a t i e n t s S e p a r a t e d i n t o M e d i c a l l y C o n g r u e n t and I n c o n g r u e n t Groups U n i v a r i a t e A n a l v s e s : P a i n M e a s u r e s C o r r e l a t i o n M a t r i x : P a i n M e asures Means and S t a n d a r d D e v i a t i o i n s t o r C o g n i t i v e Me a s u r e s 1 4 5 47 48 49 Means and S t a n d a r d D e v i a t i o n s : C o n t i n u o u s D emographic Data 63 P e r c e n t a g e Breakdown ot C a t e g o r i c a l Demographic Data 64 P a t i e n t C h a r a c t e r i s t i c s : Means and U n i v a r i a t e A n a l v s e s 66 T a b l e 18. MANOVA Summarv T a b l e t o r C o g n i t i v e Measures 67 68 70 7 1 7 2 73 7 5 7 6 7 6 v i i T a b l e 19. U n i v a r i a t e A n a l y s e s : C o g n i t i v e Measures T a b l e 2 U . C o r r e l a t i o n M a t r i x : C o g n i t i v e Measures 7 7 7 8 T a b l e 21. Means and S t a n d a r d D e v i a t i o n s : A t t e c t i v e Me a s u r e s T a b l e 22. C o r r e l a t i o n M a t r i x : • A t t e c t i v e Measures T a b l e 23. R e l a t i o n s h i p s Between P a i n Measures and C o g n i t i v e and A t t e c t i v e Measures 80 80 8 2 T a b l e 24. C o r r e l a t i o n s Among Measures ot S e v e r i t v and Svmotom P r e s e n t a t i o n and Denendent M e a s u r e s 8 5 T a b l e 25. P a t i e n t C h a r a c t e r i s t i c s : Means and S t a n d a r d D e v i a t i o n s 88 T a b l e 26. P a i n M e a s u r e s : Me an s and U n i v a r i a t e A n a l v s e s bv D i a g n o s t i c Group 89 T a b l e 27. C o g n i t i v e M e a s u r e s : Means and U n i v a r i a t e A n a l v s e s bv D i a g n o s t i c Groups 9 1 T a b l e 28. A t t e c t i v e M e a s u r e s : Means and U n i v a r i a t e A n a l v s e s bv D i a g n o s t i c Groups 93 T a b l e 29. Measures ot M e d i c a l l v I n c o n g r u e n t Symptoms: Means and U n i v a r i a t e A n a l y s e s by D i a g n o s t i c Groups 94 V i i ACKNOWLEDGEMENTS I would l i k e to thank my s u p e r v i s o r . Dr. Kenneth C r a i g i o r h i s a d v i s e and s u p p o r t i n the d e s i g n , c o m p l e t i o n , and w r i t i n g o i t h i s p r o j e c t . A d d i t i o n a l l y , the committee members. Dr. S t a n l e y C o r e n and Dr. W o l i g a n g L i n d e n were o i i n v a l u a b l e a s s i s t a n c e , p a r t i c u l a r l v i n the d e s i g n , m e t h o d o l o g y , and a n a l y s i s o i d a t a . H e a t h e r H a d i i s t a v r o 1 o p o l o u s was o i tremendous a s s i s t a n c e i n the d a t a c o l l e c t i o n and a n a l y s i s . F i n a l l y , I would l i k e t o e x p r e s s my a p p r e c i a t i o n to P e t e r Kemp t o r h i s s u p p o r t and encouragement. 1 I N T R O D U C T I O N I t has been a r g u e d t h a t the p e r c e p t i o n ot o a i n i s a l t e r e d i n c h r o n i c o a i n p a t i e n t s and t h a t t h i s i s one ot the major t a c t o r s r e s p o n s i b l e t o r the d e v e l o p m e n t and m a i n t e n a n c e ot the c h r o n i c p a i n (Chapman, 1978; S t e r n b a c h , 1 9 76). Two o p p o s i n g t h e o r e t i c a l p e r s p e c t i v e s have been p r o p o s e d to c h a r a c t e r i z e the n a t u r e ot changes i n the r e s p o n s e ot c h r o n i c p a i n s u t t e r e r s to p a i n t u l s t i m u l a t i o n . T hese p e r s p e c t i v e s have been c a l l e d the " h v p e r v i g i l a n c e " and the " a d a p t a t i o n - l e v e l " models ot p a i n p e r c e p t i o n . The h v p e r v i g i l a n c e model has l e d t o the p r e d i c t i o n t h a t c h r o n i c p a i n p a t i e n t s w i l l be more r e s p o n s i v e t o p a i n t u l s t i m u l i b e c ause t h e y t e n d to t o c u s most or a l l ot t h e i r a t t e n t i o n on p a i n t u l s e n s a t i o n s ("Chapman, 1978; 1986). In c o n t r a s t , the a d a p t a t i o n - l e v e l model o r e d i c t s t h a t c h r o n i c p a i n p a t i e n t s w i l l be l e s s r e s p o n s i v e to p a i n t u l s t i m u l i b e c a u s e , r e l a t i v e to t h e c o n s t a n t o a i n thev have been e x p e r i e n c i n g , a d d i t i o n a l s t i m u l i w i l l be iudged to be l e s s s i g n i f i c a n t ( R o l l m a n , 1979) . D e s p i t e the a p p a r e n t c o n t r a d i c t i o n , v a r i o u s r e s e a r c h t i n d i n g s can be tound to s u p p o r t both p r e d i c t i o n s , but w i t h g r o u p s of p a t i e n t s s u t t e r i n g trom d i t t e r e n t t v p e s ot c h r o n i c p a i n c o n d i t i o n s . P a i n p a t i e n t s p r e s e n t i n g w i t h d i s o r d e r s i n w h i c h p h y s i c a l p a t h o l o g y i s u n c l e a r - a n d w h i c h a r e a s s o c i a t e d w i t h h i g h e r l e v e l s ot a n x i e t y have b e e n ' t o u n d to have lower p a i n t h r e s h o l d and t o l e r a n c e l e v e l s i n c o m p a r i s o n t o p e o p l e who do not have c h r o n i c p a i n . T h i s t i n d i n g has been i n t e r p r e t e d as e v i d e n c e s u p p o r t i n g t h e p r e d i c t i o n s ot the h v p e r v i g i l a n c e model ( B r a n d s & S c h m i d t , 1987; Maluw et a l . , 198U; Malow & O l s o n , 1981; Scudds e t a l . , 1 9 8 7 ) . The o p p o s i n g p o s i t i o n has been s u p p o r t e d w i t h c h r o n i c p a i n p a t i e n t s who p r e s e n t w i t h c l e a r o r g a n i c p a t h o l o g y and t o r whom a n x i e t y i s n o t a s a l i e n t t e a t u r e ot t h e i r p a i n c o n d i t i o n . T h e s e p a t i e n t s have been t o u n d to have h i g h e r p a i n t h r e s h o l d and t o l e r a n c e l e v e l s t h a n p e o p l e w i t h o u t c h r o n i c p a i n and t h e t i n d i n g has been i n t e r p r e t e d as e v i d e n c e s u p p o r t i n g the a d a p t a t i o n - l e v e l model ( N a l i b o r l e t a l . , 1981; Cohen e t a l . , 1983; Yang e t a l . , 1983; 1983; Lipman e t a l . , 1 9 8 7 ) . The d i f f e r e n t s e t s ot t i n dings- a t t r a c t a t t e n t i o n t o t h e r o l e s ot p a t h o p h y s i o l o g i c a l and ot t h e p e r c e p t i o n ot t a l s e s e n s e ot d u a l i t y - be n o t e d t h a t b o t h the c a l t a c t o r s depend uoon o r g a n i c p a t h o l o g y has r o n i c p a i n p a t i e n t s t u n c t i o n a i " . O r g a n i c l y a t t r i b u t a b l e to t i o n s r e t e r t o sed bv p s v c h o 1 o g i c a 1 p p a r e n t p h y s i c a l c a u s e T h i s d i s t i n c t i o n has s t i c w i t h t h e p s y c h o l o g i c a l t a c t o r s as d e t e r m i n a n t s p a i n . I n t h e i n t e r e s t ot a v o i d i n g a i n t h e e x p e r i e n c e ot p a i n , i t s h o u l d d o m i n a n t p s y c h o l o g i c a l and p h y s i o l o g i b i o l o g i c a l s u b s t r a t e s . The p r e s e n c e o r a b s e n c e o i c l e a r p r o v i d e d t h e b a s i s t o r c l a s s i t y i n g ch i n t o two c a t e g o r i e s : " o r g a n i c " and " c o n d i t i o n s r e t e r t o d i s o r d e r s p r i m a r i p h v s i c a l c a u s e s , and t u n c t i o n a i c o n d i d i s o r d e r s t h o u g h t to be p r i m a r i l y c a u t a c t o r s b e c a u s e ot an a b s e n c e ot an a ( D o r l a n d ' s M e d i c a l D i c t i o n a r y , 1 9 8 9 ) . been c r i t i c i z e d as e x c e s s i v e l v s i m p i i a c c e p t a n c e ot m u l t i d i m e n s i o n a l models ot p a i n ( B e l l i s s i m o & T u n k s , 1984; T u r k , Meichenbaum, & G e n e s t , 1983; W a d d e l i et a l . 1980; 1984; W a d d e l i & M a i n , 1 9 8 4 ) . P a i n i s now c o n s i d e r e d to be a m u l t i d i m e n s i o n a l phenomenon a l w a y s i n v o l v i n g c o g n i t i v e and a t t e c t i v e components i n a d d i t i o n to p h v s i c a l f a c t o r s w i t h a l l components c o n s t a n t l y i n t e r a c t i n g t o p r o d u c e t h e f i n a l p a i n e x p e r i e n c e ( M e l z a c k & W a l l , 1 9 82). In t h e p a s t , c h r o n i c p a i n c o n d i t i o n s were t h o u g h t t o be f u n c t i o n a l o r ' p s y c h o l o g i c a l l y b a s e d ' i t t h e r e were an a b s e n c e ot c l e a r o r g a n i c p a t h o l o g y . However, b e c a u s e i t i s now r e c o g n i z e d t h a t b o t h p h y s i c a l and p s y c h o l o g i c a l f a c t o r s a r e p r e s e n t i n anv c h r o n i c p a i n c o n d i t i o n ( w h e t h e r t h e r e i s p h v s i c a l p a t h o l o g y o r n o t ) , a t t e m p t s have been made to d i f f e r e n t i a t e p a t i e n t s who p r o v i d e p o s i t i v e e v i d e n c e ot p s v c h o l o g i c a l d y s t u n c t i o n . T h e s e p a t i e n t s a r e l e s s l i k e l v to r e s p o n d t o p h v s i c a l t r e a t m e n t s ( i . e . , s u r g e r v , m e d i c a t i o n , e t c . ) and may r e q u i r e a more d e t a i l e d p s v c h o l o g i c a l a s s e s s m e n t as i t r e l a t e s to t h e i r d i s o r d e r ( R a n s t o r d , C a i r n s , & Mooney, 197b; R e e s o r & C r a i g , 1988; W a d d e l i e t a l . , 1980; 1 9 8 4 ) . R e e s o r & C r a i g (1988) d i t t e r e n t i a t e d p a t i e n t s on t h e b a s i s ot w h e t h e r o r not t h e v e x h i b i t e d svmptoms t h a t were " m e d i c a l l v i n c o n g r u e n t " w i t h known u n d e r l y i n g anatomy or p h v s i o l o g v u s i n g e s t a b l i s h e d d i a g n o s t i c p r o c e d u r e s ( R a n s t o r d e t a l . , 197b; W a d d e l i e t a l . , 1980; 1 9 8 4 ) . They f o u n d e v i d e n c e of i n e f f e c t i v e c o p i n g s t r a t e g i e s , c a t a s t r o p h i c c o g n i t i o n s , h i g h a n x i e t y l e v e l s , and h i g h e r s e n s o r y i n t e n s i t y r a t i n g s ot a p a i n t u l s t i m u l u s i n p a t i e n t s w i t h m e d i c a l l v i n c o n g r u e n t symptoms r e l a t i v e t o p a t i e n t s who d i d not e x h i b i t m e d i c a l l y i n c o n g r u e n t symptoms. T h i s t i n d i n g i s s u g g e s t i v e ot t h e wavs i n w h i c h c h r o n i c p a i n p a t i e n t s may d i t t e r i n t h e i r r e s p o n s e t o p a i n . C o p i n g s t r a t e g i e s , p a i n r e l a t e d c o g n i t i o n s , and a n x i e t y l e v e l s may be i m p o r t a n t f a c t o r s t h a t d e t e r m i n e w h e t h e r t h e p r e d i c t i o n s ot t h e h y p e r v i g i l a n c e or t h e a d a p t a t i o n - 1 e v e 1 m o d els a r e met. S t u d i e s t h a t have e x a m i n e d t h e s e two models ot p a i n p e r c e p t i o n i n t h e p a s t have u s e d S i g n a l D e t e c t i o n T h e o r y (SDT) m e t h o d o l o g y i n o r d e r t o s e p a r a t e l y e v a l u a t e two components ot p a i n p e r c e p t i o n , t h e s e n s o r y s e n s i t i v i t y to p a i n and t h e r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s as p a i n f u l (Malow e t a l . , 198U; Malow & O l s o n , 1981; N a l i b o t t e t a l . , 1981; Cohen e t a l . , 1983; Yang et a l . , 1 9 8 5 ) . B e c a u s e ot v a r i a t i o n s i n t h e p r o c e d u r e s e m p l o y e d i n t h e s e s t u d i e s , however, t h e e t t e c t ot c h r o n i c p a i n on p a i n s e n s i t i v i t y and r e s p o n s e b i a s i s s t i l l n o t c l e a r . I n v e s t i g a t i o n s w h i c h s u p p o r t t h e p r e d i c t i o n ot t h e h y p e r v i g i l a n c e model and t h o s e w h i c h s u p p o r t t h e p r e d i c t i o n ot t h e a d a p t a t i o n - l e v e l model have g e n e r a l l v u s e d d i t t e r e n t t y p e s ot p a i n p a t i e n t s , d i t t e r e n t t v p e s ot p a i n s t i m u l i , d i t t e r e n t f o r m a t s ot SDT, and wide r a n g e s i n t h e number ot s t i m u l u s t r i a l s . The p u r p o s e ot t h i s r e s e a r c h was t o examine r e s p o n s e s t o p a i n f u l s t i m u l i i n c h r o n i c p a i n p a t i e n t s w i t h and w i t h o u t m e d i c a l l v i n c o n g r u e n t svmptoms i n c o m p a r i s o n t o a matched n o r m a l c o n t r o l g r o u p . S i g n a l D e t e c t i o n T h e o r y was us e d to 5 s e p a r a t e l y e v a l u a t e b o t h t h e s e n s o r y s e n s i t i v i t y and t h e r e s p o n s e b i a s components o f p a i n r e p o r t s among t h e s e t h r e e g r o u p s . In a d d i t i o n , r e l a t i o n s h i p s between r e s p o n s e s to p a i n f u l s t i m u l i and c o g n i t i v e and a f f e c t i v e v a r i a b l e s were e x a m i n e d . I t was i n t e n d e d t h a t t h i s r e s e a r c h s h o u l d h e l p to e l u c i d a t e some o f t h e c o n d i t i o n s under w h i c h t h e p r e d i c t i o n s o f t h e h y p e r v i g i 1 a n c e and a d a p t a t i o n - 1 e v e 1 m o d els would be s a t i s f i e d . The r e v i e w o f t h e r e l e v a n t l i t e r a t u r e w i l l b e g i n w i t h a d e s c r i p t i o n of t h e h y p e r v i g i 1 a n c e and a d a p t a t i o n - 1 e v e 1 m o d e l s f o l l o w e d by a b r i e f summary of SDT m e t h o d o l o g y . R e s e a r c h on p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s w i l l t h e n be r e v i e w e d w i t h SDT s t u d i e s p r e s e n t e d and c r i t i q u e d s e p a r a t e l y f r o m o t h e r i n v e s t i g a t i o n s . F i n a l l y , the c l a s s i f i c a t i o n o f p a i n p a t i e n t s w i t h n o n o r g a n i c s i g n s w i l l be d i s c u s s e d . 6 L I T E R A T U R E REVIEW T h e H v p e r v i g i l a n c e M o d e l . T h e h v p e r v i g i l a n c e m o d e l o f p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s h a s d e v e l o p e d f r o m C h a p m a n ' s ( 1 9 7 8 ; 1 9 8 6 ) d i s c u s s i o n o f t h e i n f l u e n c e o f p e r c e p t u a l v i g i l a n c e i n t h e d e v e l o p m e n t o f a c h r o n i c p a i n c o n d i t i o n . C h apman p r o p o s e d t h a t some c h r o n i c p a i n p a t i e n t s d e v e l o p a p e r c e p t u a l h a b i t o f d i r e c t i n g most o r a l l o f t h e i r a t t e n t i o n t o t h e i r p a i n a n d s i g n s o f s o m a t i c d i s t r e s s . A s a c o n s e q u e n c e o f t h i s h v p e r v i g i l a n c e , t h e s e p a t i e n t s a r e p r e d i c t e d t o h a v e l o w e r p a i n t h r e s h o l d a n d t o l e r a n c e l e v e l s . N u m e r o u s e x p l a n a t i o n s h a v e b e e n p r o p o s e d t o a c c o u n t f o r t h i s a t t e n t i o n a l s h i f t . A t a b a s i c l e v e l , C h a p m a n ( 1 9 8 6 ) r e p o r t s t h a t p a i n " o f t e n d e m o n s t r a t e s a u n i q u e a b i l i t y t o c a p t i v a t e a t t e n t i o n " ( p p . 1 6 0 - 1 6 1 ) . C h r o n i c p a i n p a t i e n t s h a v e b e e n c h a r a c t e r i z e d by n u m e r o u s a u t h o r s a s h a v i n g r e s t r i c t e d m ovement, d e c r e a s e d a t t e n t i o n t o t h e i r e n v i r o n m e n t , a n d i n c r e a s e d s o m a t i c p r e o c c u p a t i o n ( F o r d y c e , 1976; S t e r n b a c h , 1976; P i l o w s k y , C h a p m a n , & B o n i c a , 1 9 7 7 ; a n d M e l z a c k & W a l l , 1 9 8 2 ) . I t h a s a l s o b e e n r e c o g n i z e d t h a t t h e p h y s i c a l l i m i t a t i o n s o f t e n a s s o c i a t e d w i t h p a i n f u l s t a t e s r e n d e r i t d i f f i c u l t ( o r i m p o s s i b l e ) f o r t h e i n d i v i d u a l t o c o n t i n u e w i t h e v e r v d a y a c t i v i t i e s . I n a d d i t i o n , f a m i l y a n d s o c i a l r e l a t i o n s h i p s a r e o f t e n s t r a i n e d a n d w e a k e n e d l e a v i n g t h e s u f f e r e r a l o n e t o f o c u s o n h i s / h e r a f f l i c t i o n ( F o r d y c e , 1976; M e l z a c k 5> W a l l , 1 9 82; a n d S t e r n b a c h , 1 9 7 6 ) . A n x i e t y a b o u t t h e s i g n i f i c a n c e o f t h e 7 p a i n ( i . e . , w h e t h e r i t i n d i c a t e s a l i f e o r l i f e - s t y l e t h r e a t e n i n g e v e n t ) has a l s o been s u g g e s t e d as a t t r a c t i n g a t t e n t i o n t o t h e p a i n (Chapman, 1986). O t h e r t h e o r i e s r e g a r d i n g t h e i n t e r n a l f o c u s o f a t t e n t i o n f o u n d i n c h r o n i c p a i n p a t i e n t s i n c l u d e t h e b e h a v i o u r a l ( F o r d y c e , 1976) and t h e c o g n i t i v e ( P e n n e b a k e r , 1982) p e r s p e c t i v e s . B e h a v i o u r a l t h e o r y s u g g e s t s t h a t t h e i n t e r n a l f o c u s o f a t t e n t i o n d e v e l o p s as a p e r c e p t u a l h a b i t b e c a u s e of t h e r e i n f o r c e m e n t ( e . g . , sympathy and a t t e n t i o n ) p r o v i d e d by s i g n i f i c a n t o t h e r s when t h e p a t i e n t r e p o r t s h i s / h e r s u f f e r i n g . C o g n i t i v e t h e o r y p u r p o r t s t h a t p a s t e x p e r i e n c e s r e s u l t i n t h e d e v e l o p m e n t of c o g n i t i v e schemas or s e t s . T h e s e schemas i n v o l v e t h e b e l i e f t h a t h e /she has a m a l i g n a n t c o n d i t i o n and l e a d t h e i n d i v i d u a l t o s e a r c h ( o r be h y p e r v i g i l a n t ) f o r c o n f i r m i n g s o m a t i c c u e s . The h y p e r v i g i 1 a n c e model has been a s s o c i a t e d w i t h s o m a t i z a t i o n d i s o r d e r s and h y p o c h o n d r i a s i s i n r e c e n t r e s e a r c h ( L i p m a n e t a l . , 1987; Scudds e t a l . , 1 9 8 7 ) . T h i s i m p l i e s t h a t t h e p a i n r e p o r t e d by t h e s e p a t i e n t s i s h i g h l y o v e r e x a g g e r a t e d and p e r h a p s , u n r e a l i s t i c . R e g a r d l e s s of t h e r e a s o n f o r t h e h y p e r v i g i 1 a n c e , i t has been f o u n d t h a t t h e f o c u s s i n g o f a t t e n t i o n on a p a r t i c u l a r s e n s a t i o n r e s u l t s i n th e r e p o r t e d enhancement of the s e n s a t i o n ( S c h i f f , 1980; L e v i n e e t a l . , 1 9 8 2 ) . P a i n s e n s a t i o n s a r e p e r c e i v e d as more p a i n f u l when a t t e n t i o n i s d i r e c t e d t o w a r d them and a r e d i m i n i s h e d when s u b j e c t s a r e d i s t r a c t e d ( L e v e n t h a l e t a l . , 1979; M i l l e r e t a l . , 1979; A h l e s e t a l . , 1983; McCaul & M a l o t t , 1 9 8 4 ) . Many of t h e c o g n i t i v e o a i n r e d u c t i o n t e c h n i q u e s i n v o l v e some f o r m o f d i s t r a c t i o n ( T u r k , Meichenbaum, & G e n e s t , 1 9 8 3 ) . I t i s p o s s i b l e , t h e r e f o r e , t h a t h v p e r v i g i l a n c e e n h a n c e s s e n s o r y s e n s i t i v i t y t o p a i n and n o t j u s t t h e t e n d e n c y t o r e p o r t s e n s a t i o n s as p a i n f u l . The A d a p t a t i o n - L e v e l Model A d a p t a t i o n - 1 e v e 1 t h e o r y was f i r s t p r o p o s e d by H e l s o n ( 1964) t o a c c o u n t f o r t h e o b s e r v a t i o n t h a t p e r c e p t i o n s of a p a r t i c u l a r s t i m u l u s v a r y as t h e c o n t e x t o r b a c k g r o u n d s t i m u l i c h a n g e . B a s i c a l l y , t h e t h e o r y c o n t e n d s t h a t when an o b s e r v e r makes a judgement a b o u t some q u a l i t y of a s t i m u l u s ( e . g . , s i z e , c o l o r , l o u d n e s s , e t c . ) , h e / s h e e s t a b l i s h e s a p e r s o n a l ( s u b j e c t i v e ) s c a l e upon w h i c h t o base t h e d e c i s i o n . The " a d a p t a t i o n - l e v e l " r e f e r s t o t h e s t i m u l u s i n t e n s i t y t h a t e l i c i t s a n e u t r a l o r medium r e s p o n s e . A l l o t h e r s t i m u l i a r e j u d g e d r e l a t i v e t o t h i s r e f e r e n c e p o i n t ( i . e . , t h e y a r e 'more' o r ' l e s s * of t h e q u a l i t y b e i n g j u d g e d ) . The a d a p t a t i o n - 1 e v e 1 i s fo r m e d by t h e c o m b i n a t i o n of a l l i n t e r n a l and e x t e r n a l f a c t o r s t h a t s u r r o u n d t h e o b s e r v e r . H e l s o n d i v i d e d t h e s e f a c t o r s i n t o t h r e e c l a s s e s of s t i m u l i : f o c a l , b a c k g r o u n d , and r e s i d u a l . The f o c a l s t i m u l u s i s t h a t w h i c h i s c u r r e n t l y b e i n g e v a l u a t e d . The b a c k g r o u n d s t i m u l i c o m p r i s e t h o s e t h a t p r o v i d e t h e c o n t e x t f o r t h e f o c a l s t i m u l u s w i t h i n the e x p e r i m e n t a l s i t u a t i o n ( e . g . , r a n g e of s t i m u l u s i n t e n s i t i e s e n c o u n t e r e d ) . The r e s i d u a l s t i m u l i i n c l u d e f a c t o r s t h a t a r e not under e x p e r i m e n t a l c o n t r o l , f o r example, p a s t e x p e r i e n c e , b i o l o g i c a l and p s y c h o l o g i c a l s t a t e s . T h u s , p e r c e p t u a l judgements a r e p r o p o s e d t o be r e l a t i v e t o some r e f e r e n c e p o i n t ( o r a d a p t a t i o n l e v e l ) w h i c h r e f l e c t s t h e o b s e r v e r ' s p e r s o n a l a d j u s t m e n t t o t h e gamut of f a c t o r s f a c i n g h i m / h e r . A d a p t a t i o n - 1 e v e 1 t h e o r y has been e x t e n d e d t o p a i n p e r c e p t i o n by R o l l m a n (1979) who f o u n d t h a t j u d g e m e n t s of p a i n were b a s e d on c o m p a r i s o n s w i t h p r e v i o u s l y e x p e r i e n c e d p a i n l e v e l s . He p r o p o s e d t h a t c h r o n i c p a i n p a t i e n t s judge e x t e r n a l n o x i o u s s t i m u l i r e l a t i v e t o a h i g h e r a d a p t a t i o n l e v e l t h a n p a i n - f r e e i n d i v i d u a l s b e c a u s e of t h e i r p e r s i s t e n t e x p o s u r e t o i n t e r n a l d i s c o m f o r t . T h i s r e a s o n i n g l e d t o t h e p r e d i c t i o n t h a t c h r o n i c p a i n p a t i e n t s would have h i g h e r p a i n t h r e s h o l d s and would be l e s s l i k e l y t o r e p o r t s e n s a t i o n s as p a i n f u l t h a n p a i n - f r e e i n d i v i d u a l s . T h i s i s t h e o p p o s i t e p r e d i c t i o n t o t h a t p r o p o s e d by t h e h y p e r v i g i l a n c e m o d e l . The h y p e r v i g i l a n c e and a d a p t a t i o n - l e v e l models have r e f e r r e d t o ' c h r o n i c p a i n p a t i e n t s ' as a g e n e r a l o r homogeneous g r o u p ; however, t h e r e i s c o n s i d e r a b l e d i v e r s i t y among c h r o n i c p a i n p a t i e n t s as t o t h e o r i g i n and n a t u r e of t h e i r p a i n p r o b l e m and t h e i r p s y c h o l o g i c a l w e l l - b e i n g . B o t h m o d e l s a p p e a r t o have r e c e i v e d s u p p o r t i n p a s t r e s e a r c h u s i n g S i g n a l D e t e c t i o n T h e o r y (SDT) m e t h o d o l o g y , but under d i f f e r e n t c i r c u m s t a n c e s , and w i t h d i f f e r e n t t y p e s of c h r o n i c p a i n p o p u l a t i o n s . B e f o r e t h i s r e s e a r c h i s r e v i e w e d , SDT w i l l be b r i e f l y p r e s e n t e d . t o S i g n a l D e t e c t i o n T h e o r y (SDT) S i g n a l D e t e c t i o n T h e o r y p r o v i d e s a method of m e a s u r i n g p e r c e p t u a l j u d g e m e n t s t h a t s e p a r a t e l y e v a l u a t e s t h e i n f l u e n c e of s e n s o r y s e n s i t i v i t y and t h e w i l l i n g n e s s t o r e p o r t s e n s o r y e v e n t s . The t h e o r y c o n t e n d s t h a t p e r c e p t u a l j u d g e m e n t s a r e s t a t i s t i c a l d e c i s i o n s t h a t depend upon b o t h s e n s o r y and n o n s e n s o r y f a c t o r s . The s e n s o r y f a c t o r s i n c l u d e t h e i n t e n s i t y of t h e s t i m u l u s t h a t i s b e i n g j u d g e d and t h e s e n s i t i v i t y of t h e o b s e r v e r . They a r e r e f l e c t e d by t h e o b s e r v e r ' s a c c u r a c y i n d e t e c t i n g a s t i m u l u s o r a c c u r a t e l y d i s c r i m i n a t i n g between d i f f e r e n t s t i m u l u s i n t e n s i t i e s and a r e e v a l u a t e d by an i n d e x o f d i s c r i m i n a t i o n a b i l i t y ( d ' ) . The n o n s e n s o r y f a c t o r s t h a t i n f l u e n c e p e r c e p t u a l j u d g e m e n t s i n c l u d e a t t i t u d e , e x p e c t a n c y , l e a r n i n g , and m o t i v a t i o n . T h e s e a f f e c t j u d g e m e n t s by a l t e r i n g t h e t e n d e n c y f o r t h e o b s e r v e r t o g i v e a c e r t a i n r e s p o n s e , a t e n d e n c y t h a t i s m e a s u r e d by an i n d e x c a l l e d t h e r e s p o n s e b i a s o r c r i t e r i o n ( b e t a ) . S i g n a l D e t e c t i o n T h e o r y was o r i g i n a l l y d e r i v e d f r o m a g e n e r a l m a t h e m a t i c a l t h e o r y of s t a t i s t i c a l d e c i s i o n s (Swets et a l . , 1 9 6 1 ) . The t h e o r y p r o v i d e s a way of e v a l u a t i n g how d e c i s i o n s a r e made when p e o p l e a r e f a c e d w i t h ambiguous d a t a and was o r i g i n a l l y a d a p t e d f o r e v a l u a t i n g s i g n a l d e t e c t i o n i n r a d a r o p e r a t i o n s i n 1955 (Swets e t a l . , 1 9 6 1 ) . I t has s i n c e become a v a l u a b l e t o o l i n t h e p s y c h o p h y s i c a l measurement of p e r c e p t u a l j u d g e m e n t s b e c a u s e i t p r o v i d e s a way t o examine the c o n t r i b u t i o n o f s e n s o r y s e n s i t i v i t y and 11 d e c i s i o n a l b i a s e s (Swets et a l . , 1 9 61). The t h e o r y i s b a s e d upon t h e a s s u m p t i o n t h a t t h e s i g n a l s t o be d e t e c t e d a r e p r e s e n t e d a g a i n s t a f l u c t u a t i n g b a c k g r o u n d o f s e n s o r y ' n o i s e 1 . I t i s assumed t h a t t h e d i s t r i b u t i o n of t h e n o i s e i s a n o r m a l c u r v e and t h a t t h e a d d i t i o n o f a s i g n a l on t h e n o i s e p r o d u c e s a n o r m a l c u r v e o f g r e a t e r , but o v e r l a p p i n g , o v e r a l l s e n s o r y a c t i v i t y . T h i s i s g r a p h i c a l l y p r e s e n t e d i n F i g u r e 1. Pain Report C r i t e r i o n Sensory Continuum F i g u r e 1. T h e o r e t i c a l d i s t r i b u t i o n s of an o b s e r v e r ' s r e s p o n s e s i n a s i g n a l d e t e c t i o n t a s k . The o b s e r v e r ' s t a s k i s t o d e c i d e w h e t h e r t h e l e v e l of s e n s o r y a c t i v i t y e x p e r i e n c e d i s due t o t h e s i g n a l s u p e r i m p o s e d on a b a c k g r o u n d l e v e l of s e n s o r y a c t i v i t y or to s i m p l y , t h e b a c k g r o u n d n o i s e i t s e l f . The o v e r l a p i n t h e two d i s t r i b u t i o n s i s an ambiguous zone w h i c h r e s u l t s i n t h e o b s e r v e r h a v i n g t o a d o p t a d e c i s i o n c r i t e r i o n ( i . e . , a s p e c i f i e d l e v e l of s e n s a t i o n ) whereby s e n s o r y a c t i v i t y above and below t h a t l e v e l i s j u d g e d t o i n d i c a t e t h e p r e s e n c e o r a b s e n c e of a s i g n a l , r e s p e c t i v e l y . 1 2 B e c a u s e t h e two d i s t r i b u t i o n s o v e r l a p , t h e r e a r e t o u r p o s s i b l e outcomes ot t h e d e c i s i o n : a h i t , m i s s , t a l s e a l a r m , or a c o r r e c t r e j e c t i o n . T h e s e a r e p r e s e n t e d i n t h e g r i d below ( s e e T a b l e 1 ) . Response "Yes" "No" Signal Present Signal Absent Signal + HIT MISS Noise Noise F A L S E CORRECT Alone ALARM REJECTION T a b l e 1. D e c i s i o n a l M a t r i x t o r B i n a r y SDT T a s k The p r o p o r t i o n ot h i t s t o t a l s e a l a r m s w i l l depend upon the d e g r e e ot o v e r l a p ot t h e two d i s t r i b u t i o n s and t h e c r i t e r i o n l e v e l a d o p t e d by t h e o b s e r v e r . The d e g r e e ot o v e r l a p ot t h e two d i s t r i b u t i o n s w i l l be a f f e c t e d by t h e s t r e n g t h ot t h e s i g n a l and t h e s e n s i t i v i t y ot t h e o b s e r v e r . When t h e s i g n a l s t r e n g t h i s s p e c i f i e d and h e l d c o n s t a n t , i t i s p o s s i b l e t o e v a l u a t e t h e o b s e r v e r ' s s e n s o r y s e n s i t i v i t y t o d e t e c t t h e s i g n a l . A s e n s i t i v e o b s e r v e r w i l l have a l a r g e r p r o p o r t i o n ot h i t s to t a l s e a l a r m s . S e n s o r y s e n s i t i v i t y i s g r a p h i c a l l y r e p r e s e n t e d by t h e d i s t a n c e between the means ot t h e two d i s t r i b u t i o n s and i s q u a n t i f i e d i n t h e p a r a m e t e r , d' (Swets et a l . , 1 9 6 1 ) . The c r i t e r i o n l e v e l a d o p t e d by t h e o b s e r v e r w i l l a l s o a t t e c t t h e p r o p o r t i o n ot h i t s t o t a l s e a l a r m s . I*f a v e r y c o n s e r v a t i v e l e v e l i s e m p l o y e d , the o b s e r v e r t r i e s t o m i n i m i z e t h e t a l s e a l a r m s but by d o i n g s o . w i l l a l s o r e d u c e t h e number o i h i t s . In c o n t r a s t , a l i b e r a l c r i t e r i o n w ould be a d o p t e d t o m a x i m i z e t h e p r o p o r t i o n o i h i t s b u t , i n t u r n , t h i s w i l l a l s o i n c r e a s e t h e number o i i a l s e a l a r m s . The c r i t e r i o n l e v e l c a n change w i t h , t o r example, d i t t e r e n t e x p e c t a t i o n s a b o u t t h e l i k e l i h o o d ot a s i g n a l b e i n g p r e s e n t e d , t h e m o t i v a t i o n ot t h e o b s e r v e r i n g i v i n g a c e r t a i n r e s p o n s e , and t h e c o s t ot g i v i n g a t a l s e a l a r m v e r s u s t h e b e n e t i t ot o b t a i n i n g a h i t . The c r i t e r i o n ( o r r e s p o n s e b i a s ) i s r e p r e s e n t e d q u a n t i t a t i v e l y by t h e p a r a m e t e r , b e t a . T h i s t h e o r y c a n a l s o be a p p l i e d t o t h e a s s e s s m e n t ot d i s c r i m i n a b i l i t y ot two s t i m u l i o r s i g n a l s , b o t h p r e s e n t e d a g a i n s t t h e n o r m a l l y d i s t r i b u t e d b a c k g r o u n d n o i s e (N •+• ̂  ̂  , ' + S.j). The o b s e r v e r ' s t a s k i s t o i n d i c a t e w h i c h s i g n a l was p r e s e n t e d . The same p r i n c i p l e s a r e v a l i d t o r t h i s t y p e ot t a s k as t o r t h e s i m p l e d e t e c t i o n t a s k . The s e n s i t i v i t y i n d e x ( d ' ) , however, i s a measure ot t h e o b s e r v e r ' s a b i l i t y t o d i s c r i m i n a t e between t h e two s t i m u l i w h i c h w i l l r e t l e c t h i s / h e r s e n s o r y s e n s i t i v i t y i t t h e s t i m u l i i n t e n s i t i e s a r e h e l d c o n s t a n t . In a d d i t i o n , i n s t e a d ot a b i n a r y d e c i s i o n made by t h e s u b j e c t ( i . e . , p r e s e n c e o r a b s e n c e ot a s i g n a l ; s t i m u l u s A or s t i m u l u s B ) , s u b j e c t s c an a l s o judge t h e s t i m u l i on a r a t i n g s c a l e as t o t h e c e r t a i n t y ot t h e i r d e c i s i o n . Swets et a l . (1961) p o i n t e d out t h a t t h e use ot r a t i n g s c a l e s c a n p r o d u c e r e l i a b l e d a t a w i t h tewer t r i a l s . However, M c N i c o l (1972) c a u t i o n s t h a t the number ot c a t e g o r i e s u s e d i n the r a t i n e s c a l e s h o u l d be l i m i t e d to i'.J and t h e s u b j e c t s h o u l d be p i v e n c o n s i d e r a b l e D r a c t i c c i n t h e i r use D r i o r to t h e c x o c r i m c n t . T h i s i s b e c a u s e cub i c c t : have been i o u n d to have d i f f i c u l t y i n u s i n g s e v e r a l c a t e g o r i e s s i m u l t a n e o u s l v and, c o n s e a u e n t l y , t h i s method i s l e s s s e n s i t i v e t o c h a n g e s i n d 1 t h a n SDT methods i n v o l v i n g b i n a r v i u d g e m e n t s ( C l a r k & D i l l o n , 1973; M c N i c o l , 1972). S i g n a l D e t e c t i o n T h e o r v was f i r s t u sed i n p s y c h o o h v s i c s to i n v e s t i g a t e e x t e r o c e o t i v e s e n s e s , s u c h as v i s i o n and a u d i t i o n (Swets et a l . , 19 6 1 ) . C l a r k (1974) s u b s e a u e n t l v has p r o v i d e d a t h o r o u g h e x p l a n a t i o n ot how SDT can be a D p l i e d t o t h e a s s e s s m e n t ot e x p e r i m e n t a l o a i n . T r a d i t i o n a l o a i n m e a s u r e s ( e . g . , t h r e s h o l d and t o l e r a n c e ) c o n t o u n d o a i n r e p o r t w i t h s e n s i t i v i t v t o o a i n and. t h e r e t o r e , the a b i l i t y t o s e o a r a t e l v e v a l u a t e t h e s e two components was v i e w e d as h i g h l v v a l u a b l e i n s t u d y i n g the e t t e c t s ot a n a l g e s i c s and i n a s s e s s i n g c l i n i c a l p a i n ( C l a r k , 1974; Chapman, 1977; 1 9 » 3 ) . One ot t h e main d i f f i c u l t i e s i n t h e a p p l i c a t i o n o r SDT to p a i n r e s e a r c h , however, has been the d e f i n i t i o n ot a ' s i g n a l ' . I t assumes p r i o r k nowledge w h i c h a l l o w s the r e s e a r c h e r t o s p e c i f y when a s i g n a l ( a s t i m u l u s e x p e c t e d t o c a u s e p a i n ) and a b l a n k t r i a l (a s i g n a l w h i c h does not c a u s e p a i n ) have been p r e s e n t e d . P a i n s e n s a t i o n s a r e u s u a l ! v p r e c e d e d bv o t h e r s e n s a t i o n s s u c h as warmth, h e a t , o r p r e s s u r e w h i c h does not a l l o w t o r t h e c l e a r i d e n t i t i c a t i o n o t a n o n s i g n a l t r i a l ( M c B u r n e v , 1976; R o l l m a n , 1 9 7 7 ) . P a i n r e s e a r c h e r s have c i r c ii mvented the p r o b l e m by h a v i n g s u b i e c t s r a t e t h e s t i m u l u s l e v e l s on a o a i n r a t i n p c c a l c ( C l a r k , 1969; 1 9 7 4 ) . Some r e s e a r c h e r s have used a d i f f e r e n t s e t o i s t i m u l u s l e v e l s t o r e a c h s u b i e c t on the b a s i s ot t h e i r i n d i v i d u a l o a i n t h r e s h o l d s , t h u s c o n f o u n d i n g t h e s t i m u l u s s e t w i t h i n d i v i d u a l s u b j e c t s t a c t o r s ( C l a r k , 1969; C l a r k & D i l l o n . 1973; Cohen eL a l . , 1983; N a l i b o t t et a l . , 1 9 81). T h i s ' t a i l o r i n g ' ot t h e s t i m u l u s s e t r e s u l t s i n a ' f l o a t i n g b a s e l i n e , however, w h i c h e l i m i n a t e s t h e a b i l i t v to examine b a s e l i n e d i t t e r e n c e s i n s e n s i t i v i t v . The c o n s e a u e n c e i s g r e a t e r a m b i g u i t v i n the i n t e r p r e t a t i o n ot gro u p d i t t e r e n c e i n d' or c h a n g e s i n d' as a r e s u l t ot an i n t e r v e n t i o n . The i n t e r p r e t a t i o n ot d' and b e t a as s e p a r a t e measures ot p h y s i o l o g i c a l l y b a s e d p a i n s e n s i t i v i t y and p s y c h o l o g i c a l l y or e m o t i o n a l l y b a s e d r e s p o n s e b i a s ( C l a r k , 1974) has been one ot t h e major c r i t i c i s m s ot SDT i n i t s a p p l i c a t i o n t o p a i n r e s e a r c h (Chapman, 1985; C o p p o l a & G r a c e l y , 1983; G r a c e l y , 1989; R o l l m a n , 1977). Chapman (1978) n o t e d t h a t , a l t h o u g h d' and b e t a a r e s t a t i s t i c a l l v i n d e p e n d e n t , i t i s not a c c u r a t e to say t h e y a r e not t u n c t i o n a l l v r e l a t e d . I t has been p o i n t e d out t h a t Lhese m e a s u r e s t e n d to change t o g e t h e r i n p a i n m o d u l a t i o n s t u d i e s ( i . e . , as d 1 d e c r e a s e s , r e s p o n s e c r i t e r i o n - i n c r e a s e s ) w h i c h r e s u l t s i n i n t e r p r e t i v e p r o b l e m s (Chapman, 1985; R o l l m a n , 1 9 7 7 ) . However, G r a c e l v (1989) has n o t e d t h a t a l t h o u g h c h a n g e s i n t h e s e m e asures a r e d i t t i c u l t t o i n t e r p r e t , s i t u a t i o n s i n w h i c h t h e v r e m a i n the same i s c o n f i r m a t i o n ot 16 s i m i l a r s e n s o r v a b i l i t i e s . P.ollman ( 1 976; 1977; 1 979b; 1980) has e x p r e s s e d a d d i t i o n a l c o n c e r n s w i t h th e a p p l i c a t i o n ot SDT t o D a i n r e s e a r c h . B r i e t l y , R o l l m a n (1977) has i n d i c a t e d t h a t v a r i a t i o n i n t h e m e t h o d o l o g i e s ( e . g . , number ot p r a c t i c e and e x p e r i m e n t a l t r i a l s , number ot d i t t e r e n t s t i m u l u s i n t e n s i t i e s -judged, number ot c a t e g o r i e s u s e d t o r -judgements, t v o e ot o a i n s t i m u l u s -iudged, e t c . ) e m n l o v e d i n SDT o a i n r e s e a r c h has c o n t r i b u t e d t o i n c o n s i s t e n t r e s u l t s a c r o s s l a b s . R o l l m a n (1977) t u r t h e r p o i n t e d out t h a t m e t h o d o l o g i c a l v a r i a t i o n s may a t t e c t the SDT p a r a m e t e r s , t h u s l i m i t i n g t h e e x t e r n a l v a l i d i t y to t h e c o n d i t i o n s p r e s e n t i n the s t u d y . R o l l m a n (1977) s u g g e s t e d t h a t m a n v o f the m e t h o d o l o g i c a l r e o u i r e m e n t s t o r an i d e a l SDT s t u d v were not met i n the p a i n s t u d i e s he r e v i e w e d . T h e s e r e q u i r e m e n t s i n c l u d e : a l a r g e number ot s t i m u l u s t r i a l s ( e . g . , 2 5 0 ) , a l a r g e number ot p r a c t i c e t r i a l s ( s e v e r a l h u n d r e d ) , p a r t i c u l a r l y i t s e v e r a l c a t e g o r i e s a r e used i n a r a t i n g s c a l e ( e . g . , 10), and a l i m i t e d number ot s t i m u l u s i n t e n s i t i e s t o be i u d g e d ( i . e . , t w o ) . R o l l m a n p u r p o r t s t h a t t h e s e p a r a m e t e r s a r e n e c e s s a r y t o p r o d u c e r e l i a b l e , a c c u r a t e d a t a i n SDT e x p e r i m e n t s . T h e s e r e q u i r e m e n t s t o r a SDT s t u d y a r e somewhat i m p r a c t i c a l t o r p a i n r e s e a r c h , however. The t i m e i n v o l v e d would r e s u l t i n poor s u b i e c t c o m p l i a n c e and h i g h a t t r i t i o n r a t e s , e s p e c i a l l y i n s t u d i e s i n v o l v i n g c h r o n i c o a i n p a t i e n t s . Chapman (1977) a s s e r t s t h a t R o l l m a n i s d e s c r i b i n g d e t e r m i n i n g p s y c h o p h y s i c a l f u n c t i o n s . He c o n s i d e r s t h a t SDT c a n be u s e i u l i n p a i n r e s e a r c h e v e n i t i t i s n o t a p p l i e d i n t h e r i g o r o u s p s y c h o p h y s i c a l way t h a t R o l l m a n s u g g e s t s b e c a u s e i t p r o v i d e s some i n s i g h t i n t o t h e p r o c e s s ot p a i n j u d g e m e n t s . F i n a l l y , Chapman n o t e d t h a t a l t h o u g h more p r e c i s e d a t a a r e p r o d u c e d i t o n l y two s t i m u l i a r e j u d g e d , m u l t i p l e s t i m u l i may be u s e d p r o v i d e d c o n t r o l g r o u p s a r e a l s o t e s t e d w i t h t h e same number ot s t i m u l i . In summary. Chapman (1977) n o t e d t h a t " t h e r e i s no more r e a s o n t o assume t h a t SDT d a t a must p r e c i s e l y t i t t h e a s s u m p t i o n s ot t h e e a r l i e s t SDT model t h a n t h e r e i s t o demand t h a t o t h e r d a t a e x a c t l y t i t a l l t h e r e q u i r e m e n t s ot a t - t e s t o r any o t h e r p a r a m e t r i c s t a t i s t i c a l t e s t b e t o r e i t i s u s e d . " ( p . 2 9 9 ) . Chapman ( 1 977 ; 1983 ) and C l a r k . (1974; 1987) m a i n t a i n t h a t SDT i s c u r r e n t l y a u s e f u l method ot p r o v i d i n g s e p a r a t e m e a s u r e s ot t h e s e n s o r y and r e s p o n s e b i a s components ot p a i n . They do n o t s u g g e s t t h a t i t i s t h e ' f i n a l s o l u t i o n ' to p a i n measurement, but o n l y t h a t i t p r o v i d e s u s e f u l i n f o r m a t i o n t h a t w i l l h e l p us g a i n a d d i t i o n a l i n s i g h t i n how v a r i o u s t a c t o r s a t t e c t t h e e x p e r i e n c e ot p a i n . 18 R e s e a r c h on P a i n P e r c e p t i o n i n C h r o n i c P a i n P a t i e n t s In g e n e r a l , t h e r e a r e two g r o u p s ot i n v e s t i g a t i o n s : one w h i c h r e p o r t s t h a t c h r o n i c p a i n p a t i e n t s a r e o v e r r e s p o n s i v e t o p a i n , and t h e o t h e r i n d i c a t i n g t h e c h r o n i c p a i n p a t i e n t s a r e u n d e r r e s p o n s i v e t o p a i n . S t u d i e s u s i n g SDT m e t h o d o l o g y w i l l be r e p o r t e d and c r i t i q u e d s e p a r a t e l y f r o m o t h e r i n v e s t i g a t i o n s a f t e r w h i c h an a n a l y s i s of t h i s a r e a of r e s e a r c h w i l l be p r e s e n t e d . S D T s t u d i e s on p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s . R e s e a r c h on m v o f a s c i a l p a i n d y s f u n c t i o n (MPD) has r e v e a l e d t h a t c h r o n i c p a i n p a t i e n t s w i t h t h i s d i s o r d e r have l o w e r p a i n t h r e s h o l d s t h a n n o r m a l c o n t r o l s u b j e c t s (Malow et a l . , 1 9 8 0 ) . S i g n a l d e t e c t i o n t h e o r y i n v e s t i g a t i o n s of MPD have shown t h a t a l t h o u g h t h i s c h r o n i c p a i n g r o u p i s l e s s a b l e t o d i s c r i m i n a t e between d i f f e r e n t i n t e n s i t i e s of f o c a l p r e s s u r e p a i n ( s u g g e s t i n g d e c r e a s e d s e n s i t i v i t y ) , t h e i r c r i t e r i o n t o r e p o r t s e n s a t i o n s as p a i n f u l was l o w e r t h a n n o r m a l c o n t r o l s u b j e c t s (Malow e t a l . , 1980; Malow & O l s o n , 1 9 8 1 ) . A f t e r s u c c e s s f u l t r e a t m e n t , MPD p a t i e n t s ' p a i n t h r e s h o l d s were h i g h e r , t h e i r a b i l i t y t o d i s c r i m i n a t e between s t i m u l u s i n t e n s i t i e s was i m p r o v e d and t h e i r p a i n r e p o r t c r i t e r i o n was h i g h e r . T h e s e p o s t - t r e a t m e n t r e s p o n s e s of t h e MPD p a t i e n t s were s i m i l a r t o t h e r e s p o n s e s of t h e n o r m a l c o n t r o l g r o u p (Malow & O l s o n , 1 9 81). T h u s , t h e s e c h r o n i c p a i n p a t i e n t s were f o u n d to be more l i k e l y t o r e p o r t s e n s a t i o n s as p a i n f u l t h a n p e o p l e w i t h o u t c h r o n i c p a i n 19 d e s p i t e a p p a r e n t l y l o w e r e d s e n s i t i v i t y t o t h e s t i m u l i . In c o n t r a s t t o t h e above i n v e s t i g a t i o n s t h a t f o u n d c h r o n i c p a i n p a t i e n t s t o be more r e s p o n s i v e t o p a i n f u l s t i m u l a t i o n t h a n p a i n - f r e e i n d i v i d u a l s , t h e r e a r e s e v e r a l s t u d i e s t h a t i n d i c a t e c h r o n i c p a i n p a t i e n t s a r e l e s s r e s p o n s i v e t o p a i n . N a l i b o f f e t a l . , ( 1981) and Cohen e t a l . , ( 1983) e x amined t h e r e s p o n s e s of c h r o n i c low back p a i n p a t i e n t s , c h r o n i c r e s p i r a t o r y p a t i e n t s , and n o n p a t i e n t c o n t r o l s u b j e c t s t o p a i n f u l t h e r m a l s t i m u l a t i o n . They f o u n d t h a t b o t h t h e back p a i n and c h r o n i c r e s p i r a t o r y p a t i e n t s had h i g h e r p a i n t h r e s h o l d s t h a n t h e n o n p a t i e n t c o n t r o l s u b j e c t s . S i g.n a l d e t e c t i o n t h e o r y a n a l y s i s i n d i c a t e d t h a t back p a i n p a t i e n t s showed p o o r e r d i s c r i m i n a b i l i t y of p a i n f u l r a d i a n t h e a t s t i m u l i t h a n t h e r e s p i r a t o r y p a t i e n t s and n o n p a t i e n t c o n t r o l s u b j e c t s , a g a i n s u g g e s t i n g l o w e r e d s e n s i t i v i t y t o p a i n s t i m u l i as was f o u n d w i t h th e MPD p a t i e n t s . However, t h e y d i d not f i n d any r e l i a b l e g r o u p d i f f e r e n c e s f o r b e t a ( i . e . , p a i n r e p o r t c r i t e r i o n ) . O t h e r SDT i n v e s t i g a t i o n s have a l s o r e v e a l e d t h a t c h r o n i c back p a i n p a t i e n t s have h i g h e r p a i n t h r e s h o l d s . They a l s o r e p o r t e d d e c r e a s e d d i s c r i m i n a b i l i t y f o r r a d i a n t h e a t ; however, t h e y f o u n d t h a t c h r o n i c p a i n p a t i e n t s had a h i g h e r c r i t e r i o n to r e p o r t p a i n r e l a t i v e t o n o r m a l c o n t r o l s u b j e c t s (Yang et a l . , 1983; 1 9 8 5 ) . T h a t i s , t h e y were l e s s i n c l i n e d t h a n th e n o r m a l c o n t r o l g r o u p t o c a l l the s e n s a t i o n s ' p a i n f u l ' . Yang e t a l . ( 1 9 8 5 ) a t t r i b u t e d t h e a d d i t i o n a l f i n d i n g of d i f f e r e n c e s i n t h e p a i n r e p o r t 20 c r i t e r i o n t o m e t h o d o l o g i c a l d i t t e r e n c e s . I t i s d i f f i c u l t t o draw c o n c l u s i o n s a b o u t how c h r o n i c p a i n p a t i e n t s r e s p o n d t o l a b o r a t o r y p a i n i n t h e s e SDT i n v e s t i g a t i o n s b e c a u s e o f t h e v a r i a t i o n i n t h e m e t h o d o l o g i e s e m p l o y e d . Many of t h e s t u d i e s r e q u i r e d s u b j e c t s t o make c a t e g o r y j u d g e m e n t s of i n t e n s i t y i n t h e i r SDT t a s k ( N a l i b o f f e t a l . , 1981; Cohen e t a l . , 1983; Yang e t a l . , 1 9 85). The use of c a t e g o r y j u d g e m e n t s i n SDT has been f o u n d t o be l e s s s e n s i t i v e t o c h a n g e s i n d' t h a n b i n a r y j u d g e m e n t s b e c a u s e s u b j e c t s were f o u n d t o have d i f f i c u l t y u s i n g a l l t h e c a t e g o r i e s s i m u l t a n e o u s l y and c o n s i s t e n t l y ( C l a r k & D i l l o n , 1 9 7 3 ) , p a r t i c u l a r l y i f o n l y a s m a l l number o f p r a c t i c e t r i a l s were g i v e n ( M c N i c o l , 1 9 72). I t i s n o t c l e a r how many- p r a c t i c e t r i a l s were g i v e n i n t h e s e s t u d i e s or even i f any were g i v e n a t a l l . T h e r e i s wide v a r i a t i o n among the above SDT s t u d i e s w i t h r e s p e c t t o t h e number of t r i a l s g i v e n per s t i m u l u s i n t e n s i t y , r a n g i n g f r o m 3 t r i a l s p e r i n t e n s i t y (Malow e t a l . , 1980; Malow & O l s o n , 1981) t o 26 t r i a l s p e r s t i m u l u s i n t e n s i t y ( N a l i b o f f et a l . , 1981; Cohen e t a l . , 1 9 8 3 ) . More r e l i a b l e e s t i m a t e s of t h e SDT i n d i c e s a r e g a i n e d w i t h a g r e a t e r number o f t r i a l s . T h e r e f o r e , t h e f i n d i n g s o b t a i n e d w i t h t h e s e g r e a t l y v a r y i n g numbers of e x p e r i m e n t a l t r i a l s may not be c o m p a r a b l e . In a d d i t i o n , some of t h e s t u d i e s have s e l e c t e d d i f f e r e n t s t i m u l u s i n t e n s i t i e s t o be u s e d i n t h e SDT t a s k f o r e a c h s u b j e c t b a s e d on e a c h p e r s o n ' s r e c o r d e d p a i n t h r e s h o l d (Cohen et a l . , 1983; N a l i b o f f et 21 a l . , 1 9 8 1 ). Yang and h i s c o l l e a g u e s , however, u s e d t h e same s e t o f s t i m u l i f o r a l l s u b j e c t s . C l a r k (1974) has i n d i c a t e d t h a t d' v a l u e s o b t a i n e d w i t h d i f f e r e n t s t i m u l u s i n t e n s i t i e s f o r e a c h s u b j e c t a r e n o t d i r e c t l y c o m p a r a b l e . F i n a l l y , two t y p e s of p a i n s t i m u l i were u s e d i n t h e s e s t u d i e s : f o c a l p r e s s u r e (Malow e t a l . , 1980; Malow & O l s o n , 1981) and r a d i a n t h e a t (Cohen e t a l . , 1983; N a l i b o f f e t a l . , 1981; Yang e t a l . , 1 9 8 5 ) . R o l l m a n (1983) has s u g g e s t e d c a u t i o n i n c o m p a r i n g r e s u l t s of s t u d i e s u s i n g d i f f e r e n t p a i n s t i m u l i . T h u s , w h i l e t h e r e i s some c o n s i s t e n c y a c r o s s d i f f e r e n t m e t h o d o l o g i e s i n t h a t i t a p p e a r s t h a t a l l c h r o n i c p a i n p a t i e n t s e x h i b i t a r e d u c e d a b i l i t y t o d i s c r i m i n a t e between p a i n f u l s t i m u l i , one c a n n o t be s u r e b e c a u s e of t h e above m e t h o d o l o g i c a l v a r i a t i o n s . O t h e r i n v e s t i g a t i o n s o f p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s . R e c e n t s t u d i e s have been u n d e r t a k e n t o a s c e r t a i n w h e t h e r c h r o n i c p a i n s t a t e s a f f e c t p a i n t o l e r a n c e l e v e l s ( B r a n d s & S c h m i d t , 1987; L i p m a n e t a l . , 1987; Scudds e t a l . , 1 9 8 7). B r a n d s and S c h m i d t (1987) f o u n d t h a t c h r o n i c low back p a i n p a t i e n t s w i t h no a p p a r e n t p a t h o l o g i c a l b a s i s f o r t h e i r c o n d i t i o n had l o w e r t o l e r a n c e t o c o l d p r e s s o r p a i n t h a n n o r m a l c o n t r o l s . Scudds e t a l . (1987) examined p a i n t h r e s h o l d s , t o l e r a n c e l e v e l s , and p e r s o n a l i t y c o r r e l a t e s of f i b r o s i t i s p a t i e n t s , r h e u m a t o i d a r t h r i t i s p a t i e n t s , and n o r m a l c o n t r o l s u b j e c t s . F i b r o s i t i s i s a c h r o n i c p a i n c o n d i t i o n i n w h i c h t h e r e i s an " a b s e n c e of l a b o r a t o r y , r a d i o g r a p h i c , and e x a m i n a t i o n e v i d e n c e of i n f l a m m a t o r y 22 d i s e a s e " ( S c u d d s e t a l . , 1987, p. 5 6 3 ) . The f i b r o s i t i s g r o u p was r e p o r t e d t o s c o r e s i g n i f i c a n t l y h i g h e r t h a n normal c o n t r o l s on h y p o c h o n d r i a s i s , d e p r e s s i o n , a n x i e t y , and s o c i a l i n t r o v e r s i o n . In a d d i t i o n , t h e y showed s i g n i f i c a n t l y l o w e r p a i n t h r e s h o l d s and t o l e r a n c e l e v e l s t h a n n o r m a l c o n t r o l s u b j e c t s and r h e u m a t o i d p a t i e n t s . The a u t h o r s s u g g e s t t h a t t h e s e r e s u l t s a r e c o n s i s t e n t w i t h t h e h y p e r v i g i 1 a n c e model of p a i n p e r c e p t i o n . In c o n t r a s t , L ipman e t a l . (1987) compared the t o l e r a n c e l e v e l s t o r a d i a n t h e a t s t i m u l i o f c h r o n i c p a i n p a t i e n t s and n o r m a l v o l u n t e e r s . The c h r o n i c p a i n g r o u p c o n s i s t e d of p a t i e n t s e x p e r i e n c i n g s e v e r e p a i n r e s u l t i n g f r o m a v a r i e t y o f d i s o r d e r s . In g e n e r a l , however, t h e c o n d i t i o n s were a l l c o n s i d e r e d t o have o r g a n i c e t i o l o g i e s and t o be t r e a t a b l e by n e u r o s u r g i c a l i n t e r v e n t i o n . They f o u n d t h a t t h e c h r o n i c p a i n p a t i e n t s e x h i b i t e d h i g h e r t o l e r a n c e l e v e l s o f p a i n f u l t h e r m a l s t i m u l i t h a n n o r m a l v o l u n t e e r s . F u r t h e r m o r e , t h e y f o u n d t h a t t h e p a i n t o l e r a n c e l e v e l s d e c r e a s e d i n t h e c h r o n i c p a i n g r o u p f o l l o w i n g s u r g i c a l i n t e r v e n t i o n s and were s i m i l a r t o t h e r e s p o n s e s of t h e n o r m a l v o l u n t e e r s . 23 A n a l y s i s ot R e s e a r c h on P a i n P e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s I t i s d i i i i c u l t t o r e a c h a c o n c l u s i o n r e g a r d i n g a l t e r e d p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s b e c a u s e of the method v a r i a t i o n u s e d i n t h e above s t u d i e s . T h e r e a r e some c o n s i s t e n t d i f f e r e n c e s , however, between s t u d i e s i n d i c a t i n g o v e r r e s p o n s i v e n e s s o r u n d e r r e s p o n s i v e n e s s t o p a i n i n c h r o n i c p a i n p a t i e n t s s u c h a s , t h e t y p e of p a i n s t i m u l i u s e d and t h e t y p e o f p a i n d i s o r d e r s t u d i e d . Type o f p a i n s t i m u l u s u s e d . A c o n s i s t e n t m e t h o d o l o g i c a l d i f f e r e n c e between s t u d i e s f i n d i n g o v e r r e s p o n s i v e n e s s and t h e s e r e p o r t i n g u n d e r r e s p o n s i v e n e s s t o p a i n i n c h r o n i c p a i n p a t i e n t s c o n c e r n s th e g e n e r a l t y p e of p a i n i n d u c t i o n t e c h n i q u e u s e d . I n v e s t i g a t i o n s t h a t have r e p o r t e d p a i n p a t i e n t s t o have low p a i n t h r e s h o l d s u s e d f o c a l p r e s s u r e and c o l d p r e s s o r p a i n i n d u c t i o n methods ( B r a n d s C S c h m i d t , 1987; Malow e t a l . , 1980; Malow & O l s o n , 1981; S c udds e t a l . , 1 9 8 7 ) . T h e s e p a i n i n d u c t i o n methods have been termed ' t o n i c s t i m u l i ' b e c a u s e t h e y p r o d u c e deep, p r o l o n g e d p a i n f u l s e n s a t i o n s . In c o n t r a s t , i n v e s t i g a t i o n s t h a t f o u n d p a i n p a t i e n t s t o have h i g h t h r e s h o l d s t o p a i n u s e d r a d i a n t h e a t s t i m u l i ( C ohen e t a l . , 1983; Lipman e t a l . , 1987; N a l i b o f f e t a l . , 1981; and Yang e t a l . , 1985) and one s t u d y s i m p l y u s e d a q u e s t i o n n a i r e f o r m a t ( i . e . , no p a i n was i n d u c e d ) (Yang e t a l . , 1 9 8 3 ) . R a d i a n t h e a t and o t h e r s p r o d u c i n g s h o r t - t e r m o r t r a n s i e n t p a i n ( e . g . , e l e c t r i c s h o c k ) have been termed ' p h a s i c s t i m u l i 1 . 24 T o n i c and p h a s i c s t i m u l i a r e b e l i e v e d t o a c t on t h e n e r v o u s s v s t e m i n d i f f e r e n t wavs. C o l d p r e s s o r and p r e s s u r e p a i n a r e b e l i e v e d t o p r i m a r i l y s t i m u l a t e t h e l a r g e u n m y e l i n a t e d 'C' f i b r e s o f n o c i c e p t i o n and p r o d u c e s l o w , d i f f u s e , and a c h i n g s e n s a t i o n s (Chapman, 1 9 8 6 ) . T h e s e methods o f p a i n i n d u c t i o n a r e f a v o r e d by some i n v e s t i g a t o r s b e c a u s e of t h e s i m i l a r i t y w i t h c l i n i c a l p a i n c o n d i t i o n s (Malow e t a l . , 1980; 1 9 8 7 ) . However, t h i s t y p e of s t i m u l u s may n o t be a p p r o p r i a t e f o r SDT i n v e s t i g a t i o n s . S i g n a l D e t e c t i o n T h e o r y r e q u i r e s many r e p e a t e d p r e s e n t a t i o n s of b r i e f s t i m u l i (Chapman, 1985). The n a t u r e of t o n i c p a i n i n d u c t i o n t e c h n i q u e s i s s u c h t h a t i t t a k e s some t i m e f o r e a c h s t i m u l u s t o be a d m i n i s t e r e d ( e . g . , 60 s e c o n d s o r more) w h i c h n e c e s s a r i l v l i m i t s t h e number o f t r i a l s g i v e n p e r s t i m u l u s i n t e n s i t y ( e . g . , o n l y 3 t r i a l s p e r i n t e n s i t y were a d m i n i s t e r e d i n Malow's i n v e s t i g a t i o n s ) . R a d i a n t h e a t p a i n i n v o l v e s b r i e f (3 t o U s e c o n d s ) , d i s c r e t e s t i m u l i and, a l t h o u g h i t i s not c o n s i d e r e d t o be as s i m i l a r to t h e e x p e r i e n c e of c h r o n i c p a i n , i t i s a w i d e l y u s e d f o r m o f p a i n i n d u c t i o n t e c h n i q u e ( R o l l m a n & H a r r i s , 1 9 8 7). T h i s i s b e c a u s e i t i s a v e r y r e l i a b l e and e a s i l y - c o n t r o l l e d s o u r c e o f p a i n s t i m u l i . P h a s i c p a i n has been f o u n d t o s t i m u l a t e t h e A - d e l t a f i b r e s . In a d d i t i o n , r a d i a n t h e a t ( i n c o n t r a s t t o e l e c t r i c a l and m e c h a n i c a l p a i n i n d u c t i o n t e c h n i q u e s ) was f o u n d t o c o n f o r m t o t h e a s s u m p t i o n t h a t t h e v a r i a n c e s o f t h e two u n d e r l y i n g d i s t r i b u t i o n i n SDT a r e e q u a l ( C l a r k , 1969; R o l l m a n , 1976). T h i s a s s u m p t i o n i s 25 i m p o r t a n t f o r t h e p a r a m e t r i c c a l c u l a t i o n s ot d' ( R o l l m a n , 1 9 7 6 ) . F i n a l l y , t h e r e l a t i v e l y b r i e f a d m i n i s t r a t i o n t i m e f o r s t i m u l u s p r e s e n t a t i o n makes r a d i a n t h e a t a s u i t a b l e p a i n i n d u c t i o n t e c h n i q u e f o r SDT b e c a u s e more t r i a l s may be a d m i n i s t e r e d i n a g i v e n t i m e . D i f f e r e n c e s i n t h e t y p e o f p a i n p o p u l a t i o n s t u d i e d . An i m p o r t a n t d i s t i n c t i o n between the s t u d i e s t h a t f o u n d o v e r r e s p o n s i v e n e s s i n p a i n p a t i e n t s and t h o s e t h a t f o u n d u n d e r r e s p o n s i v e n e s s was t h e t y p e of p a i n p a t i e n t s t u d i e d . A g e n e r a l d i f f e r e n c e a p p e a r s t o be w h e t h e r t h e p a i n c o n d i t i o n had an o b v i o u s o r g a n i c c a u s e o r n o t . One o f the d i s t i n c t d i a g n o s t i c c r i t e r i a f o r MPD, e s t a b l i s h e d by L a s k i n , has been t h a t t h e r e i s no e v i d e n c e of o r g a n i c p a t h o l o g y i n t h e a f f e c t e d a r e a ( i n S c o t t , 1 9 8 1 ) . The I n t e r n a t i o n a l A s s o c i a t i o n f o r t h e S t u d y of P a i n : S u b c o m m i t t e e on Taxonomy (1986) a l s o i n d i c a t e d t h a t t h e p h y s i c a l p a t h o l o g y of MPD was unknown. T h i s i s a l s o t r u e f o r f i b r o s i t i s and, i n a d d i t i o n , Scudds e t a l . ( 1987) r e p o r t e d a s t r o n g a s s o c i a t i o n between f i b r o s i t i s and h y p o c h o n d r i a s i s . Low p a i n t o l e r a n c e l e v e l s were r e p o r t e d i n c h r o n i c p a i n p a t i e n t s f o r whom no o r g a n i c c a u s e was a p p a r e n t ( B r a n d s & S c h m i d t , 1987). In c o n t r a s t , N a l i b o f f e t a l . (1981) and Cohen e t a l . (1983) b o t h u s e d p a t i e n t s " t y p i c a l of an o r g a n i c a l l y b a s e d d i s o r d e r w i t h o u t m a j o r p s y c h i a t r i c p r o b l e m s . " (Cohen et a l . , 1983, p. 2 4 7 ) . Lipman e t a l . ( 1987) a l s o c o n d u c t e d t h e i r s t u d y u s i n g p a i n p a t i e n t s w i t h o b v i o u s o r g a n i c c a u s e s and who were l i k e l y t o o b t a i n r e l i e f f r o m upcoming s u r g i c a l i n t e r v e n t i o n s . Yang et a l . (1983) were l e s s c l e a r a : to the n a t u r e or the c o n d i t i o n s ot t h e i r o a i n p a t i e n t s , however Yang e t a l . (19 85) i n d i c a t e d t h a t t h e i r p a i n p a t i e n t s were d i a g n o s e d w i t h h e r n i a t e d lumbar d i s k s , m v o i a s c i a l svndrome, and o s t e o a r t h r i t i s . Malow and O l s o n (198U) have commented on t h e p o s s i b i l i t y t h a t p e o p l e w i t h ' o r g a n i c a l l y c a u s e d ' p a i n s yndromes may d i t t e r i n t h e i r r e s p o n s e to p a i n i n c o m p a r i s o n w i t h p e o p l e who do n o t e x h i b i t o b v i o u s o r g a n i c s i g n s . They s u g g e s t e d t h a t " t h e a b s e n c e of o r g a n i c c a u s e s f o r c h r o n i c p a i n may r e s u l t i n p e o p l e who a r e t e m p o r a r i l y more s e n s i t i v e t o p a i n t u l s t i m u l a t i o n t h a n n o r m a l i n d i v i d u a l s . " ( p . 7 1 ) . O t h e r i n v e s t i g a t i o n s have f o u n d t h a t p a i n p a t i e n t s w i t h u n c l e a r o r no a p p a r e n t o r g a n i c c a u s e t o r t h e i r d i s c o m f o r t r e p o r t g r e a t e r i n t e n s i t y ot p a i n t h a n p a t i e n t s w i t h c l e a r p h y s i c a l e t i o l o g i e s ( L e a v i t t e t a l . , 1979; P e r r y e t a l . 1 9 8 8 ) . Cohen e t a l . ( 1 9 8 3 ) , however, have s u g g e s t e d t h a t t h e d i f f e r e n c e i n r e s u l t s may i n s t e a d " r e f l e c t t h e d i t t e r e n t p s y c h o l o g i c a l components ot t h e d i s o r d e r s . " ( p . 2 5 1 ) . L e a v i t t & G a r r o n (1979) t o u n d t h a t p s y c h o l o g i c a l t a c t o r s were r e l a t e d t o i n c r e a s e d p a i n r e p o r t i n e i t h e r ' o r g a n i c ' or ' n o n - o r g a n i c ' p a t i e n t s . I t i s i n t e r e s t i n g t o n o t e t h a t b o t h MPD and t i b r o s i t i s have been s t r o n g l y a s s o c i a t e d w i t h s t r e s s and a n x i e t y and i n b o t h c o n d i t i o n s , t h e p h y s i c a l c a u s e i s u n c l e a r ( S c h w a r t z e t a l . , 1979; Malow et a l . , 198U; S c o t t , 1981; Scudds e t a l . , 1 9 8 7 ) . C h a r a c t e r i s t i c symptoms ot a n x i e t y i n c l u d e w o r r y and a n t i c i p a t i o n ot p o s s i b l e c a l a m i t y t o s e l t o r o t h e r s and h v p e r v i g i l a n c e t o r p o s s i b l e m i s t o r t u n e ( A m e r i c a n P s y c h i a t r i c A s s o c i a t i o n , D i a g n o s t i c and S t a t i s t i c a l M a nual ot M e n t a l D i s o r d e r s I I I - R e v i s e d , 1 9 8 7 ) . R e s e a r c h on t h e r e l a t i o n s h i p between p a i n and a n x i e t y has g e n e r a l l y s u p p o r t e d t h e o b s e r v a t i o n t h a t a n x i e t y i s a s s o c i a t e d w i t h i n c r e a s e d p a i n r e p o r t , d e c r e a s e d p a i n t h r e s h o l d and t o l e r a n c e l e v e l s ( L e p a n t o e t a l . , 1965; H a lsam, 1966; M e n d l e r & Watson, 1966; K l u s m a n , 1975; W e i s e n b e r g e t a l . , 1977; K e n t , 1984; S t e r n b a c h , 1986; W harton & C l a r k , 1 9 8 7 ) . T e c h n i q u e s t o r e d u c e a n x i e t y r e s u l t e d i n i n c r e a s e d p a i n t h r e s h o l d and t o l e r a n c e (Bobey & D a v i d s o n , 1970; E l t o n £> S t a n l e y , 1 9 76). F e a r e d s t i m u l i , w h e t h e r e x t e r n a l o r i n t e r n a l ( e . g . , s o m a t i c s e n s a t i o n s ) , have been f o u n d t o c a p t u r e a t t e n t i o n ( W i l l i a m s e t a l . , 1988; Chapman, 1 9 8 6 ) . B u s h n e l l e t a l . (1985) f o u n d t h a t t h e s e l e c t i v e a t t e n t i o n t o p a i n f u l h e a t s t i m u l i i m p r o v e d s u b j e c t s ' a b i l i t y to d e t e c t t e m p e r a t u r e c h a n g e s . They a t t r i b u t e d t h i s f i n d i n g t o c h a n g e s i n t h e s e n s o r y n e u r a l pathways and n o t t o c h a n g e s i n t h e s u b j e c t s ' d e c i s i o n c r i t e r i o n . I t i s p l a u s i b l e t h a t t h e h v p e r v i g i l a n c e model i s a p p l i c a b l e t o a s u b g r o u p of c h r o n i c p a i n p a t i e n t s who a r e p a r t i c u l a r l y a n x i o u s a b o u t t h e i r c o n d i t i o n and a r e a t t e n t i v e t o s i g n s o f s o m a t i c d i s t r e s s . A r e v i e w o f t h e s i g n i f i c a n c e of t h e o r g a n i c / f u n c t i o n a 1 c l a s s i f i c a t i o n s y s t e m w i l l f o l l o w i n c o n j u n c t i o n w i t h a r e v i e w o f t h e r o l e o f 2 8 c o g n i t i v e and a f f e c t i v e f a c t o r s i n t h e e x p e r i e n c e of c h r o n i c p a i n . C l a s s i f i c a t i o n o f p a i n p a t i e n t s One o f t h e m a j o r ways t h a t p a i n p a t i e n t s have been c l a s s i f i e d i n t h e p a s t has been on t h e b a s i s of t h e p r e s e n c e or a b s e n c e o f i d e n t i f i a b l e o r g a n i c c a u s e s . T h i s d i a g n o s t i c p r o c e s s has y i e l d e d two c a t e g o r i e s of p a i n p a t i e n t s . T h o s e p a t i e n t s w i t h o b v i o u s u n d e r l y i n g p h y s i c a l c a u s e s f o r t h e i r p a i n have been c l a s s i f i e d as h a v i n g ' o r g a n i c ' or ' s o m a t o g e n i c ' d i s o r d e r s and have been c o n s i d e r e d t o d i s p l a y ' r e a l p a i n ' ( T u r k 6. Rudy, 1987 ) . However, t h o s e p a t i e n t s c o m p l a i n i n g of p e r s i s t e n t p a i n i n t h e a b s e n c e of i d e n t i f i a b l e p h y s i c a l ' c a u s e s o r whose p a i n r e p o r t s were d i s p r o p o r t i o n a t e t o t h e t i s s u e damage have been c l a s s i f i e d as h a v i n g ' f u n c t i o n a l ' o r ' p s y c h o g e n i c ' d i s o r d e r s , and have been c o n s i d e r e d t o d i s p l a y ' u n r e a l p a i n ' ( i . e . , p a i n t h a t i s e m o t i o n a l l y b a s e d ) ( T u r k & Rudy, 1987). T h i s t y p e o f mind-body d u a l i s m has been c r i t i c i z e d i n t h e wake of c u r r e n t f o r m u l a t i o n s of p a i n w h i c h c o n s i d e r p a i n to i n v o l v e s e n s o r y - d i s c r i m i n a t i v e , m o t i v a t i o n a l - a f f e c t i v e , and c o g n i t i v e - e v a l u a t i v e components w h i c h a r e c o n s t a n t l y i n t e r a c t i n g i n t h e e x p e r i e n c e of p a i n ( M e l z a c k & W a l l , 1 9 8 2 ) . T h e r e has been s u b s t a n t i a l s u p p o r t f o r t h e r o l e of c o g n i t i o n and a f f e c t as m e d i a t i n g f a c t o r s i n t h e p e r c e p t i o n of p a i n ( C r a i g , 1989; E l t o n , 1987; Thompson, 1981; T u r k , Meichenbaum, & G e n e s t , 19 8 3 ) . In a d d i t i o n , the o r g a n i c / f u n c t i o n a l d i s t i n c t i o n has e n c o u n t e r e d p r o b l e m s . I t i s r a r e t o f i n d an o r g a n i c a l l y c a u s e d p a i n c o n d i t i o n t h a t does not a l s o i n v o l v e p s y c h o l o g i c a l v a r i a b l e s ( B e l l i s i m o & T u n k s , 1984; T u r k e t a l . , 1983; W a d d e l l & M a i n , 1 9 8 4 ) . O r t h o p a e d i c t r e a t m e n t s o f t e n have been i n e f f e c t i v e w i t h a p p a r e n t l y o r g a n i c a l l y c a u s e d d i s o r d e r s b e c a u s e of t h e t e n d e n c y t o i g n o r e t h e p s y c h o l o g i c a l f a c t o r s ( L e a v i t t & G a r r o n , 1979; L e a v i t t , 1987; D e r e b e r y & T u l l i s , 1986; W a d d e l l e t a l . , 1 9 8 0 ) . F i n a l l y , an a l t e r n a t i v e e x p l a n a t i o n f o r " f u n c t i o n a l " d i s o r d e r s i s a p p a r e n t i n t h e t e n d e n c y t o a t t r i b u t e i n a p p r o p r i a t e p a i n r e p o r t to m a l i n g e r i n g o r ' s e c o n d a r y g a i n ' ( e . g . , f i n a n c i a l i n c e n t i v e s t h r o u g h c o m p e n s a t i o n o r l i t i g a t i o n ) . S e v e r a l s t u d i e s , however, have f a i l e d t o f i n d a r e l a t i o n s h i p between n o n o r g a n i c s i g n s and c o m p e n s a t i o n o r l i t i g a t i o n c l a i m s ( L e a v i t t e t a l . , 1982; M e l z a c k et a l . , 1985; R e e s o r & C r a i g , 1988; W a d d e l l e t a l . , 19 8 0 ) . I t i s becoming a p p a r e n t i n r e c e n t r e s e a r c h t h a t t h e d e g r e e o f d e t e c t a b l e p h y s i c a l p a t h o l o g y c o n t r i b u t e s l e s s t o t h e v a r i a n c e i n p a i n p e r c e p t i o n and d i s a b i l i t y i n c h r o n i c p a i n p a t i e n t s t h a n does t h e c o g n i t i v e a p p r a i s a l and e m o t i o n a l r e a c t i o n t o t h e c o n d i t i o n ( B a r n e s et a l . , 1989; F l o r & T u r k , 1987; L a c r o i x e t a l . , 1990; Lee et a l . , 1989; M a i n & W a d d e l l , 1984; P o l a t i n e t a l . , 1989; T u r k & Rudy, 1987; and W a d d e l l , 1 9 8 7 ) . P a i n p a t i e n t s who r e p o r t e d c a t a s t r o p h i c c o g n i t i o n s r e g a r d i n g t h e i r p a i n and a s e n s e of h e l p l e s s n e s s i n c o n t r o l l i n g t h e p a i n a l s o r e p o r t e d h i g h e r 30 i n t e n s i t i e s of p a i n and i n c r e a s e d d i s a b i l i t y . T h i s was t r u e f o r p a t i e n t s w i t h l i m i t e d o r g a n i c f i n d i n g s and f o r p a t i e n t s w i t h c l e a r o r g a n i c c a u s e s ( F l o r & T u r k , 1987; K e e f e et a l . , 1989; and S p i n h o v e n et a l . , 1 9 8 9 ) . B a n d u r a e t a l . (1987) f o u n d t h a t s e 1 f - e f f i c a c y to w i t h s t a n d c o l d p r e s s o r p a i n was c o r r e l a t e d w i t h i n c r e a s e d p a i n t o l e r a n c e and a c t i v a t i o n of o p i o i d a n a l g e s i c s y s t e m s . S e 1 f - e f f i c a c y i s d e f i n e d by t h e a u t h o r s as a p e r s o n ' s b e l i e f o f h i m / h e r s e l f as b e i n g c a p a b l e t o a c h i e v e c e r t a i n l e v e l s of p e r f o r m a n c e and t o m a i n t a i n c o n t r o l o v e r e v e n t s . T h u s , i t a p o e a r s t h a t a s e n s e of c o n t r o l o v e r p a i n i s a s s o c i a t e d w i t h ;nc r e l e a s e of e ndogenous o p i o i d s u b s t a n c e s w h i c h a c t as a n a l g e s i c s ( i . e . , d e c r e a s e s e n s i t i v i t y t o pa i n ) • Co g n i t i o r . s o f c o n t r o l h av e been a s s o c i a t e d w i t h d e c r e a s e d p a i n r e p o r t and i n c r e a s e d p a i n t o l e r a n c e i n p a s t r e s e a r c h ( B o w e r s , 1963; H i l l e t a l . , 1952; L e p a n t o e t a l . , 1965; M e n d l e r & Watson, 1966; HaIsam, 1966; S z p i l e r & E p s t e i n , 1976; F l o r & T u r k , 1987; S p i n h o v e n e t a l . , 1 9 8 9 ) . C h r o n i c p a i n p a t i e n t s who e x h i b i t s e l f - e f f i c a c y t o c o n t r o l o r cope w i t h p a i n may r e p r e s e n t t h e s u b g r o u p of p a t i e n t s who have been r e p o r t e d to be l e s s r e s p o n s i v e t o p a i n f u l s t i m u l i and who a p p e a r to c o n f o r m t o t h e p r e d i c t i o n s of t h e A d a p t a t i o n - l e v e l m o d e l . E m o t i o n a l r e s p o n s e t o s t r e s s has been l i n k e d to b i o c h e m i c a l f a c t o r s t h a t a f f e c t p a i n s e n s i t i v i t y . A n i m a l r e s e a r c h c o n d u c t e d t o i n v e s t i g a t e a l t e r e d p a i n p e r c e p t i o n u n d e r s t r e s s f u l c o n d i t i o n s r e v e a l e d t h a t a n a l g e s i a and h y p e r a l g e s i a c o u l d be p r o d u c e d by t h e same s i t u a t i o n i n r a t s ( J o r u m , 1 9 8 8 a ) . T h e c r i t i c a l f a c t o r l e a d i n g to e a c h of t h e s e outcomes a p p e a r e d t o be t h e a n i m a l ' s e m o t i o n a l b e h a v i o u r e x h i b i t e d d u r i n g t h e n o n n o x i o u s s t r e s s f u l s i t u a t i o n . R a t s t h a t l a y q u i e t l y were f o u n d t o be l e s s s e n s i t i v e t o p a i n whereas r a t s t h a t were a g i t a t e d and " h y p e r e m o t i o n a l " e x h i b i t e d h y p e r s e n s i t i v i t y t o p a i n . H y p e r e m o t i o n a 1 i t y r e f e r s t o motor a g i t a t i o n , d e f e c a t i o n , an v o c a l i z a t i o n and i s c o n s i d e r e d t o be an i n d e x of a n x i e t y i n a n i m a l s ( J o r u m , 1988b; T a n a k a e t a l . , 1 9 8 3 ) . Jorum (1988b) f u r t h e r i n v e s t i g a t e d t h e b i o c h e m i c a l b a s e s f o r t h e s e r e s p o n s e s i n a d d i t i o n t o s e e i n g w h e t h e r t h e h y p e r a l g e s i c r e s p o n s e c o u l d be c o n d i t i o n e d . He f o u n d t h a t n o r a d r e n e r g i c mechanisms m e d i a t e d t h e h y p e r a l g e s i c r e s p o n s e and t h a t the h y p e r a l g e s i c r e s p o n s e c o u l d be c o n d i t i o n e d s u c h t h a t t h e "mere a n t i c i p a t i o n of an e v e n t w h i c h has e a r l i e r p r o d u c e d h y p e r e m o t i o n a l i t y w i t h a s u b s e q u e n t d e c r e a s e i n n o c i c e p t i v e t h r e s h o l d r e s u l t s i n h y p e r a l g e s i a " ( p . 3 5 3 ) . Jorum (1988b) s u g g e s t e d t h a t t h e e x p e c t a t i o n of an u n p l e a s a n t e v e n t , t h e r e f o r e , may r e s u l t i n d e c r e a s e s i n p a i n t h r e s h o l d . He f u r t h e r s u g g e s t e d t h a t t h e i m p l i c a t i o n of t h e above r e s u l t s i s t h a t a n x i e t y ( p r e s e n t e d as h y p e r e m o t i o n a l i t y ) may be a c r i t i c a l f a c t o r i n t h e d e v e l o p m e n t of h y p e r a l g e s i a . T h e s e f i n d i n g s l e a d t o t h e i m p l i c a t i o n t h a t p a i n p a t i e n t s who a r e d i s t r e s s e d by t h e i r p a i n c o n d i t i o n and e x h i b i t i n c r e a s e d s o m a t i c p r e o c c u p a t i o n ( h v p e r v i g i l a n c e ) may be i n c r e a s i n g t h e i r s e n s o r y s e n s i t i v i t y t o p a i n f u l s e n s a t i o n s . 3Z I t i s now r e c o g n i z e d t h a t b o t h p h y s i c a l and p s y c h o l o g i c a l f a c t o r s w i l l be p r e s e n t i n any c h r o n i c p a i n c o n d i t i o n . C o n s e q u e n t l y , e f f o r t s have been made to i d e n t i f y , t h r o u g h th e p h y s i c a l e x a m i n a t i o n , t h o s e p a t i e n t s who may r e q u i r e a more d e t a i l e d p s y c h o l o g i c a l a s s e s s m e n t b e f o r e u n d e r g o i n g a p h y s i c a l t r e a t m e n t s u c h as s u r g e r y ( W a d d e l i e t a l . , 1 9 8 0 ) . T h i s a p p e a r s t o be b e s t done on t h e b a s i s o f e s t a b l i s h i n g t h e p r e s e n c e o f n o n - o r g a n i c s i g n s r a t h e r t h a n by e x c l u s i o n , d e t e r m i n i n g t h e a b s e n c e of o r g a n i c s i g n s ( B i g o s & B a t t i e , 1987; D e r e b e r y & T u l l i s , 1986; Doxey et a l . , 1988; M a i n & W a d d e l i , 1984; W a d d e l i e t a l . , 1980; W a d d e l i , 1 9 8 7 ) . N o n - o r g a n i c s i g n s o r symptoms r e f e r t o r e p o r t s o f p a i n o r r e a c t i o n s t o p h y s i c a l e x a m i n a t i o n t h a t a r e v a g u e , p o o r l y l o c a l i z e d , or d e v i a t e f r o m a n a t o m i c a l p r i n c i p l e s ( W a d d e l i e t a l . , 1980; W a d d e l i et a l . , 1 9 84). N o n - o r g a n i c s i g n s / s y m p t o m s have been termed " m e d i c a l l y i n c o n g r u e n t symptoms" and have a l s o been i d e n t i f i e d by e x a g g e r a t e d and n o n - a n a t o m i c a l p a i n d r a w i n g s ( R a n s f o r d et a l . , 1976; R e e s o r & C r a i g , ' 1 9 8 8 ) . C l a s s i f i c a t i o n o f m e d i c a l l y c o n g r u e n t vs m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n . R e e s o r & C r a i g (1988) c l a s s i f i e d p a i n p a t i e n t s on t h e b a s i s of t h e p r e s e n c e or a b s e n c e of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms. M e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n was a s s e s s e d u s i n g t h r e e m e a s u r e s t h a t i n v o l v e d i f f e r e n t modes of c o m m u n i c a t i o n : b e h a v i o u r a l , v e r b a l s e l f - r e p o r t , and p i c t o r i a l . P a i n p a t i e n t s were c l a s s i f i e d as e x h i b i t i n g a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n i f t h e y e x h i b i t e d s i g n s t h a t s u r p a s s e d a s e t c r i t e r i o n f o r a t l e a s t one of the m e a s u r e s . A d i s c r i m i n a n t f u n c t i o n a n a l y s i s i n d i c a t e d t h a t 85% of t h e p a t i e n t s were c l a s s i f i e d c o r r e c t l y a c c o r d i n g t o t h i s s y s t e m . The b e h a v i o u r a l component was a s s e s s e d u s i n g a measure of n o n o r g a n i c p h y s i c a l s i g n s p r e s e n t d u r i n g a p h y s i c a l e x a m i n a t i o n ( W a d d e l i et a l . , 1 9 8 0 ) . The n o n o r g a n i c p h y s i c a l s i g n s c o n s i s t of r e p o r t s of p a i n t h a t do not c o r r e s p o n d t o a n a t o m i c a l p r i n c i p l e s and i n c l u d e t h e f o l l o w i n g symptoms: s u p e r f i c i a l and deep n o n - a n a t o m i c a 1 1 y b a s e d t e n d e r n e s s , r e p o r t of p a i n d u r i n g mock e x a m i n a t i o n t e s t s , i n c r e a s e i n s t r a i g h t l e g r a i s i n g when the p a t i e n t i s d i s t r a c t e d , d i s t u r b a n c e s of m u s c l e s t r e n g t h or s e n s a t i o n i n n e i g h b o r i n g a r e a s t h a t do n o t c o r r e s p o n d t o n e u r o l o g i c a l o r a n a t o m i c a l s u b s t r a t e s , and o v e r r e a c t i o n t o e x a m i n a t i o n . N o n o r g a n i c p h y s i c a l s i g n s were more l i k e l y t o be o b s e r v e d i n p a t i e n t s f o r whom c o n v e n t i o n a l m e d i c a l t r e a t m e n t s had f a i l e d ( W a d d e l i e t a l . , 1 9 8 0 ) . Two o r g r e a t e r n o n o r g a n i c s i g n s were f o u n d t o c o r r e l a t e w i t h t h e h y p o c h o n d r i a s i s and h y s t e r i a s c a l e s on t h e M i n n e s o t a M u l t i p h a s i c P e r s o n a l i t y I n v e n t o r y (MMPI) but d i d n o t c o r r e l a t e w i t h t h e F o r K v a l i d i t y s c a l e s s u g g e s t i n g t h a t t h e s i g n s a r e n o t i n d i c a t i v e of m a l i n g e r i n g (Doxey et a l . , 1988; W a d d e l i e t a l . , 1 9 80). O t h e r s t u d i e s have f a i l e d to f i n d a r e l a t i o n s h i p between n o n o r g a n i c p h y s i c a l s i g n s and c o m p e n s a t i o n o r l i t i g a t i o n c l a i m s ( L e a v i t t et a l . , 1982; M e l z a c k e t a l . , 1985; R e e s o r & C r a i g , 1988; and Repco & C o o p e r , 1 9 8 3 ) . The p r e s e n c e of m u l t i p l e n o n o r g a n i c s i g n s i s i n d i c a t i v e of p a t i e n t s l i k e l y t o have a poor r e s u l t f r o m s u r g e r v and who may r e q u i r e a more d e t a i l e d p s y c h o l o g i c a l a s s e s s m e n t ( D e r e b e r y & T u l l i s , 1986; Doxey e t a l . , 1988; D z i o b a & Doxey, 1984; and W a d d e l l e t a l . , 1 9 8 0 ) . T h i s measure was f o u n d t o have h i g h r e l i a b i l i t y a c r o s s a s s e s s m e n t s ( i n t e r - r a t e r and t e s t - r e t e s t r e l i a b i l i t y c o e f f i c i e n t s have r a n g e d f r o m .78 t o .86) ( R e e s o r & C r a i g , 1988; W a d d e l l et a l . , 1980) and h i g h d i s c r i m i n a t i v e v a l i d i t y ( i . e . , d i d n o t c o r r e l a t e s i g n i f i c a n t l y w i t h o b j e c t i v e p h y s i c a l i m p a i r m e n t ) ( M a i n & W a d d e l l , 1 9 8 4 ) . The s e l f - r e p o r t component of m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n was a s s e s s e d u s i n g t h e W a d d e l l e t a l . , (1984) I n a p p r o p r i a t e Symptom I n v e n t o r y . T h i s measure c o n s i s t s of a l i s t o f s e v e n s p e c i f i c q u e s t i o n s w h i c h i n q u i r e a b o u t symptoms t h a t a r e vague, p o o r l y l o c a l i z e d , and g e n e r a l l y a r e i n c o n s i s t e n t w i t h known p h y s i o l o g i c a l and a n a t o m i c a l p r i n c i p l e s . The s c a l e has been f o u n d t o have h i g h i n t e r - r a t e r r e l i a b i l i t y (K=.58-1.00, jo < . 0 1 > and h i g h d i s c r i m i n a t i v e v a l i d i t y ( i . e . , v e r y low i n c i d e n c e i n p a t i e n t s w i t h c l e a r o r g a n i c p a t h o l o g y ) . D e r e b e r y & T u l l i s ( 1 986) c o n s i d e r t h e measure t o be v a l u a b l e i n i d e n t i f y i n g symptoms r e l a t e d t o p s y c h o l o g i c a l f a c t o r s . F i n a l l y , t h e p i c t o r a l component of m e d i c a l i n c o n g r u e n c e was a s s e s s e d by R e e s o r and C r a i g w i t h t h e P a i n D r a w i n g u s i n g t h e R a n s f o r d e t a l . (1976) s c o r i n g s y s t e m . The p a t i e n t i s 3 5 r e q u i r e d t o i n d i c a t e on an o u t l i n e of a human f i g u r e t h e l o c a t i o n and q u a l i t y o f t h e i r p a i n . The s c o r i n g s y s t e m q u a n t i f i e s n o n a n a t o m i c a 1 o r e x a g g e r a t e d f e a t u r e s of t h e d r a w i n g . A s c o r e of t h r e e o r g r e a t e r has been a s s o c i a t e d w i t h d e c r e a s e d l i k e l i h o o d t h a t t h e p a t i e n t w i l l r e s p o n d to c o n v e n t i o n a l o r t h o p o e d i c t r e a t m e n t ( D z i o b a & Doxey, 1984; T a y l o r e t a l . , 1984; Uden e t a l . , 1 9 8 8 ) . E x a g g e r a t e d or n o n a n a t o m i c a 1 p a i n p r e s e n t a t i o n i s r a r e i n p a t i e n t s w i t h o r g a n i c l e s i o n s s u c h as a h e r n i a t e d d i s k (Uden e t a l . , 1 9 8 8 ) . H i g h s c o r e s have been c o r r e l a t e d w i t h t h e h y p o c h o n d r i a s i s and h y s t e r i a s c a l e s of t h e MMPI ( R a n s f o r d e t a l . , 1 9 7 6 ) . The R a n s f o r d e t a l . , s c o r i n g s y s t e m has been u s e d w i t h h i g h i n t e r - r a t e r r e l i a b i l i t y ( c o e f f i c i e n t s r a n g e f r o m .70 t o .89) and h i g h t e s t - r e t e s t r e l i a b i l i t y ( c o e f f i c i e n t s r a n g e f r o m .77 t o .85) ( R e e s o r & C r a i g , 1988; Uden e t a l . , 1988) . The a s s e s s m e n t of i n c o n g r u e n t p a i n p r e s e n t a t i o n has been of use i n i d e n t i f y i n g p a t i e n t s who a r e l i k e l y t o have a poo r r e s u l t t o s u r g i c a l t r e a t m e n t and f o r whom a p s y c h o l o g i c a l c o n s u l t a t i o n w o u l d be h e l p f u l ( B i g o s & B a t t i e , 1987; D e r e b e r y & T u l l i s , 1986; Doxey e t a l . , 1988; W a d d e l i et a l . , 1980; 1984; W a d d e l i , 1 9 8 7 ) . I n c o n g r u e n t p a i n p r e s e n t a t i o n i s c o n s i d e r e d t o p r o v i d e i n f o r m a t i o n a b o u t t h e p a t i e n t ' s e m o t i o n a l r e s p o n s e t o t h e i r i l l n e s s and p e r c e p t i o n o f t h e i r d i s a b i l i t y ( W a d d e l i , 1987; W a d d e l i e t a l . , 1 9 8 9 ) . P a t i e n t s w i t h i n a p p r o p r i a t e p a i n p r e s e n t a t i o n s " c a n be s a i d t o be r e a c t i n g t o l i f e ' s s t r e s s e s i n a m a l a d a p t i v e way" ( D e r e b e r y & T u l l i s , 1 9 8 6 ) . I n c o n g r u e n t symptoms have been c o r r e l a t e d w i t h h i g h e r s e n s o r y i n t e n s i t y r a t i n g s of p a i n , more p h y s i c a l i m p a i r m e n t and d i s a b i l i t y , c a t a s t r o p h i c c o g n i t i o n s r e g a r d i n g p a i n , and a s e n s e o f h e l p l e s s n e s s i n a b i l i t y t o c o n t r o l p a i n ( R e e s o r & C r a i g , 1 9 88). P a t i e n t s e x h i b i t i n g n o n o r g a n i c s i g n s have a l s o been f o u n d t o have a p o o r r e s p o n s e t o p h y s i c a l t r e a t m e n t s and t o have e l e v a t e d s c o r e s on t h e h y s t e r i a and h y p o c h o n d r i a s i s s c a l e s o f t h e MMPI ( D z i o b a & Doxey, 1984; R a n s f o r d e t a l . , 1976; T a y l o r e t a l . , 1984; Uden e t a l . , 1988; W a d d e l l et a l . , 1 9 8 0 ) . P a i n p a t i e n t s who a p p e a r t o c o n f o r m t o t h e h v p e r v i g i l a n c e model of a l t e r e d p a i n p e r c e p t i o n may be i d e n t i f i a b l e on t h e b a s i s of p r e s e n c e of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms. "The e f f e c t of f a i l u r e t o o b t a i n r e l i e f f r o m c h r o n i c p a i n may ... l e a d t o a g e n e r a l s e n s i t i z i n g of t h e p a t i e n t t o a l l s o r t s of p h y s i o l o g i c a l e v e n t s ( h e i g h t e n e d s o m a t i c a w a r e n e s s ) l e a d i n g t o i n a p p r o p r i a t e p a i n p e r c e p t i o n s o r r e p o r t s ( i n a p p r o p r i a t e symptoms), i n a p p r o p r i a t e r e s p o n s e s t o p h y s i c a l e x a m i n a t i o n ( s i g n s ) and r e s u l t i n g i n a marked e x a c e r b a t i o n of t h e e x t e n t of d i s a b i l i t y f o r a g i v e n l e v e l of o b j e c t i v e p h y s i c a l i m p a i r m e n t " ( M a i n & W a d d e l l , 1984, p. 4 0 ) . R e e s o r & C r a i g (1988) s u g g e s t e d t h a t p a i n p a t i e n t s w i t h i n e f f e c t i v e c o p i n g t e c h n i q u e s and m a l a d a p t i v e c o g n i t i o n s ( w h i c h s e r v e t o a c c e n t u a t e t h e i r s u f f e r i n g ) may come t o e x h i b i t p a i n b e h a v i o u r s o u t of p r o p o r t i o n t o t h e u n d e r l y i n g p a t h o l o g y - The t e n d e n c y t o be a n x i o u s and t o engage i n m a l a d a p t i v e c o g n i t i o n s ( e . g . , c a t a s t r o p h i z i n g ) may draw a t t e n t i o n t o t h e p a i n ( i . e . , c r e a t e a s t a t e of h v p e r v i g i l a n c e ) and r e s u l t i n h y p e r s e n s i t i v i t y t o p a i n . F u r t h e r m o r e , a v i c i o u s c i r c l e w o u l d be e s t a b l i s h e d whereby t h e p a t i e n t f e e l s more p a i n , becomes more a n x i o u s and h y p e r v i g i l a n t , t h u s m a i n t a i n i n g o r e x a c e r b a t i n g t h e c h r o n i c p a i n c o n d i t i o n . An a d a p t a t i o n - l e v e l e f f e c t ( i . e . , r e d u c e d r e a c t i v i t y t o p a i n f u l s t i m u l i ) would be more l i k e l y t o be s e e n i n p a t i e n t s w i t h o u t s i g n i f i c a n t n o n o r g a n i c s i g n s , who show e f f e c t i v e c o p i n g s t r a t e g i e s , and e x h i b i t low a n x i e t y s c o r e s . I n t h i s c a s e , a p o s i t i v e c y c l e c o u l d be e s t a b l i s h e d whereby t h e p a t i e n t ' s s e l f - e f f i c a c y t o c o n t r o l p a i n i s r e i n f o r c e d . Summary and P u r p o s e o f t h e P r e s e n t I n v e s t i g a t i o n Two m o d e ls o f a l t e r e d p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s have been p r e s e n t e d : t h e h v p e r v i g i l a n c e model and t h e a d a p t a t i o n - l e v e l m o d e l . The h v p e r v i g i l a n c e model has l e d t o t h e p r e d i c t i o n t h a t c h r o n i c p a i n p a t i e n t s w i l l be more r e a c t i v e t o p a i n f u l s t i m u l i b e c a u s e t h e y t e n d t o d i r e c t most o r a l l of t h e i r a t t e n t i o n t o s i g n s of s o m a t i c d i s t r e s s . In c o n t r a s t , t h e a d a p t a t i o n - l e v e l model has l e d t o t h e p r e d i c t i o n t h a t c h r o n i c p a i n p a t i e n t s w i l l be l e s s r e a c t i v e to p a i n f u l s t i m u l i b e c a u s e t h e y w i l l j udge p a i n f u l s t i m u l i r e l a t i v e to a h i g h e r s t a n d a r d o r a d a p t a t i o n - 1 e v e 1 of p a i n t h a n p e o p l e w i t h o u t c h r o n i c p a i n . B o t h p r e d i c t i o n s have been s u p p o r t e d i n p a s t r e s e a r c h but w i t h p a t i e n t s who d i s p l a y d i f f e r e n t t y p e s o f p a i n c o n d i t i o n s . I n g e n e r a l , p a t i e n t s who r e p o r t c a t a s t r o p h i c c o g n i t i o n s and h i g h l e v e l s o f a n x i e t y r e g a r d i n g t h e i r p a i n a l s o r e p o r t g r e a t e r p a i n i n t e n s i t y . T h e s e p a t i e n t s have been i d e n t i f i e d by the d i s p l a y of m e d i c a l l y i n c o n g r u e n t symptoms. However, p a t i e n t s who do n o t d i s p l a y i n a p p r o p r i a t e symptoms, engage i n a d a p t i v e c o p i n g s t r a t e g i e s , a r e l e s s a n x i o u s , and more e f f i c a c i o u s t o c o n t r o l t h e i r p a i n a p p e a r to be l e s s r e a c t i v e t o p a i n f u l s t i m u l i . S i g n a l D e t e c t i o n T h e o r y has been u s e d t o a s s e s s t h e p r e d i c t i o n s of t h e h y p e r v i g i 1 ance and a d a p t a t i o n - 1 e v e 1 m o d els i n o r d e r t o s e p a r a t e l y e v a l u a t e s e n s o r y s e n s i t i v i t y t o p a i n and r e s p o n s e b i a s . However, m e t h o d o l o g i c a l v a r i a t i o n has r e n d e r e d t h e c o n c l u s i o n s amb i g uou s. The p u r p o s e of t h e p r e s e n t i n v e s t i g a t i o n was t o e v a l u a t e w h e t h e r the p r e d i c t i o n s of t h e two models of p a i n p e r c e p t i o n were met by p a i n p a t i e n t s w i t h d i f f e r e n t p r e s e n t a t i o n s of s y m p t o m a t o l o g y ( i . e . , t h o s e w i t h m e d i c a l l y i n c o n g r u e n t o r c o n g r u e n t symptoms). P a i n p e r c e p t i o n was a s s e s s e d u s i n g SDT m e t h o d o l o g y i n a d d i t i o n t o m e asures of p a i n t h r e s h o l d and s e l f r e p o r t of t h e s u b j e c t i v e e x p e r i e n c e of p a i n . C o g n i t i v e and a f f e c t i v e c o r r e l a t e s of t h e p a i n r e s p o n s e s were e v a l u a t e d i n o r d e r t o d e f i n e more c l e a r l y t h e c o n d i t i o n s u n d e r w h i c h hypo- o r h y p e r r e a c t i v i t y t o p a i n can be e x p e c t e d i n c h r o n i c p a i n p a t i e n t s . 39 H y p o t h e s e s and D e s i g n B e c a u s e t h i s s t u d y i n v o l v e d a p a r t i a l r e p l i c a t i o n o f a p r e v i o u s s t u d y c o n d u c t e d by t h e same r e s e a r c h l a b o r a t o r y ( R e e s o r & C r a i g , 1 9 8 8 ) , i t was e x p e c t e d t h a t t h e c l a s s i f i c a t i o n s y s t e m would p r o d u c e two a d e q u a t e l y - d i s t i n g u i s h e d g r o u p s o f p a i n p a t i e n t s : t h o s e w i t h and w i t h o u t m e d i c a l l y i n c o n g r u e n t symptoms. In a c c o r d a n c e w i t h R e e s o r and C r a i g ' s f i n d i n g s , p a t i e n t s w i t h m e d i c a l l y i n c o n g r u e n t symptoms were e x p e c t e d t o r e p o r t l e s s e f f e c t i v e c o p i n g s t y l e s , be more p r o n e t o c a t a s t r o p h i z i n g , and r e p o r t g r e a t e r p a i n i n t e n s i t y t h a n p a t i e n t s w i t h o u t i n c o n g r u e n t • symptoms. In a d d i t i o n , i t was e x p e c t e d t h a t t h e m e d i c a l l y i n c o n g r u e n t g r o u p would be more a n x i o u s and f e e l l e s s a b l e t o c o n t r o l o r manage t h e i r p a i n . An i n i t i a l a s s e s s m e n t of t h e g e n e r a l h y p o t h e s i s t h a t c h r o n i c p a i n p a t i e n t s r e s p o n d d i f f e r e n t l y t o p a i n t h a n p a i n - f r e e i n d i v i d u a l s was e x p e c t e d t o y i e l d no s i g n i f i c a n t g r o u p d i f f e r e n c e s . T h i s was b e c a u s e t h e p a t i e n t g r o u p would be r e p r e s e n t e d by a h e t e r o g e n e o u s s e l e c t i o n of p a i n p a t i e n t s . R a t h e r , t h e two m o d e ls o f p a i n p e r c e p t i o n were e x p e c t e d t o be d i f f e r e n t i a l l y s u p p o r t e d by p a t i e n t s w i t h d i f f e r e n t p a i n p r e s e n t a t i o n s . P a t i e n t s w i t h m e d i c a l l y c o n g r u e n t symptoms were e x p e c t e d t o c o n f o r m t o t h e p r e d i c t i o n s of t h e a d a p t a t i o n - l e v e l model and t h o s e w i t h m e d i c a l l y i n c o n g r u e n t symptoms were e x p e c t e d t o c o n f o r m t o t h e p r e d i c t i o n s of the h v p e r v i g i l a n c e m o d e l . The a d a p t a t i o n - l e v e l model was a n t i c i p a t e d t o be r e f l e c t e d by a h i g h t h r e s h o l d f o r p a i n and 40 by a h i g h c r i t e r i o n t o r e p o r t p a i n f r o m th e s i g n a l d e t e c t i o n a n a l y s i s . T h i s i s b e c a u s e t h e model r e f e r s t o j u d g e m e n t s o f p e r c e p t u a l s t i m u l i r e l a t i v e t o t h e o b s e r v e r ' s i n t e r n a l s t a n d a r d o r a d a p t a t i o n - l e v e l . From t h i s m o d e l , one would e x p e c t th e ' m e d i c a l l y c o n g r u e n t ' g r o u p t o have a h i g h e r c r i t e r i o n t o r e p o r t p a i n f u l s e n s a t i o n s t h a n t h e ' m e d i c a l l y i n c o n g r u e n t ' o r n o r m a l c o n t r o l g r o u p s . The h y p e r v i g i l a n c e model was e x p e c t e d t o be r e f l e c t e d by a low t h r e s h o l d f o r p a i n i n t h e m e d i c a l l y i n c o n g r u e n t p a i n g r o u p . The c r i t e r i o n t o r e p o r t s e n s a t i o n s as p a i n f u l f r o m th e s i g n a l d e t e c t i o n a n a l y s i s was e x p e c t e d t o be low r e l a t i v e t o t h e m e d i c a l l y c o n g r u e n t and n o r m a l c o n t r o l g r o u p s . T h i s i s b e c a u s e o f t h e h y p o t h e s i z e d i n c r e a s e d s o m a t i c v i g i l a n c e . In a d d i t i o n , b e c a u s e of r e s e a r c h on a t t e n t i o n , h e i g h t e n e d a n x i e t y and p a i n s e n s i t i v i t y , i t was s p e c u l a t e d t h a t t h e s i g n a l d e t e c t i o n measure o f s e n s o r y s e n s i t i v i t y ( d ' ) would be h i g h e r r e l a t i v e t o t h e o t h e r two g r o u p s . A 3 X 2, g r o u p by s e x , between g r o u p s d e s i g n was u s e d to e v a l u a t e t h e h y p o t h e s e s . Group 1 c o n s i s t e d of n o r m a l c o n t r o l s u b j e c t s ( i . e . , t h o s e w i t h o u t c h r o n i c p a i n ) . G r o u p s 2 and 3 c o n s i s t e d of c h r o n i c back, p a i n p a t i e n t s , w i t h o u t and w i t h , m e d i c a l l y i n c o n g r u e n t symptoms, r e s p e c t i v e l y . A l l g r o u p s were age and sex m a t c h e d . B e c a u s e t h i s t y p e of d e s i g n ( i . e . , q u a s i - e x p e r i m e n t a l ) y i e l d s c o r r e l a t i o n a l d a t a o n l y , c a u s a l r e l a t i o n s h i p s may not be i n t e r p r e t t e d ( C a m p b e l l & S t a n l e y , 1 9 6 3 ) . D e m o g r a p h i c v a r i a b l e s a s s e s s e d i n c l u d e d 41 age, m a r i t a l s t a t u s , s o c i o e c o n o m i c s t a t u s , and e t h n i c i t y . E x p e r i m e n t a l c o n d i t i o n s ( a m b i e n t t e m p e r a t u r e d u r i n g a h e a t d e t e c t i o n t a s k ) and f a c t o r s r e l a t e d t o c h r o n i c p a i n ( d u r a t i o n of t h e c o n d i t i o n , m e d i c a t i o n u s e , s u r g e r y , s u b j e c t i v e d i s a b i l i t y , and p h y s i c a l i m p a i r m e n t ) were a l s o a s s e s s e d . The d e p e n d e n t v a r i a b l e s c o n s i s t e d o f t h r e e g r o u p s o f m e a s u r e s : a f f e c t i v e , c o g n i t i v e , and p a i n m e a s u r e s . G e n e r a l a n x i e t y was a s s e s s e d i n a l l s u b j e c t s u s i n g t h e T r a i t S c a l e of t h e S t a t e - T r a i t A n x i e t y I n v e n t o r y ( S p i e l b e r g e r , 1 9 85). Worry and e m o t i o n a l i t y s p e c i f i c t o c h r o n i c p a i n was a s s e s s e d i n t h e p a i n p a t i e n t s u s i n g t h e P a i n E x p e r i e n c e S c a l e ( T u r k & Rudy, 1 9 8 5 ) . C o g n i t i o n s a s s o c i a t e d w i t h c h r o n i c p a i n c o n d i t i o n s i n c l u d i n g c o p i n g s t r a t e g i e s were a s s e s s e d w i t h t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e ( R o s e n s t i e l & K e e f e , 1 9 8 3 ) . F i n a l l y , t h e f o l l o w i n g p a i n m e a s u r e s were t a k e n : t h r e s h o l d f o r r a d i a n t h e a t p a i n , t h e s i g n a l d e t e c t i o n i n d i c e s of s e n s i t i v i t y ( d ' ) and r e s p o n s e b i a s ( B ) , and s u b j e c t i v e d e s c r i p t i o n s of t h e p a i n u s i n g t h e G r a c e l y R a t i n g S c a l e s of S e n s o r y I n t e n s i t y and A f f e c t i v e D i s t r e s s ( G r a c e l y e t a l . , 1 9 7 9 ) . 42 METHOD S u b j e c t s A l l s u b j e c t s were r e c r u i t e d trom th e U n i v e r s i t y H o s p i t a l , S h a u g h n e s s y S i t e , a l a r g e g e n e r a l h o s p i t a l i n V a n c o u v e r , B.C.. N ormal c o n t r o l s u b j e c t s were r e c r u i t e d trom t h e s t a i t o i the h o s p i t a l and trom v i s i t o r s t o t h e h o s p i t a l . They were e l i g i b l e t o p a r t i c i p a t e i t t h e v were: ( a ) between t h e ages ot 30 and 60 y e a r s , (b) t l u e n t i n t h e E n g l i s h l a n g u a g e , and ( c ) n o t s u f f e r i n g f r o m c h r o n i c p a i n o r t a k i n g any r e g u l a r m e d i c a t i o n . Back p a i n p a t i e n t s were r e c r u i t e d t h r o u g h th e Back P a i n C l i n i c and f r o m c o n s u l t i n g p h y s i c i a n s a s s o c i a t e d w i t h t h e Back P a i n C l i n i c a t S h a u g h n e s s y H o s p i t a l . The Back P a i n C l i n i c c o n d u c t s c o m p r e h e n s i v e a s s e s s m e n t s of c h r o n i c back p a i n p a t i e n t s r e f e r r e d f r o m g e n e r a l p r a c t i t i o n e r s o r m e d i c a l s p e c i a l i s t s . P a i n p a t i e n t s a r e r o u t i n e l y a s s e s s e d by one of two teams, e a c h c o n s i s t i n g of a g e n e r a l p r a c t i c e p h y s i c i a n , an o r t h o p a e d i c s p e c i a l i s t , a p s y c h o l o g i s t , and a p h y s i o t h e r a p i s t . C o n s e c u t i v e a d m i s s i o n s o f back p a i n p a t i e n t s who met the f o l l o w i n g c r i t e r i a were a s k e d t o p a r t i c i p a t e i n t h e s t u d y : ( a ) between t h e ages of 30 and 60 y e a r s , (b) n o t i n v o l v e d i n c o m p e n s a t i o n c l a i m s or l i t i g a t i o n w i t h r e s p e c t t o t h e i r back p a i n , ( c ) a g r e e a b l e t o a b s t a i n f r o m p a i n m e d i c a t i o n from m i d n i g h t t h e n i g h t b e f o r e t h e i r p a r t i c i p a t i o n i n t h e s t u d y , (d) s u f f i c i e n t l y f l u e n t i n t h e E n g l i s h l a n g u a g e i n o r d e r to f i l l o ut s e l f - r e p o r t i n v e n t o r i e s and t o u n d e r s t a n d i n s t r u c t i o n s , and ( e ) p r e s e n t i n g w i t h a c h r o n i c p a i n p r o b l e m of s i x months d u r a t i o n or l o n g e r . Of t h o s e who v o l u n t e e r e d , 43 s i x were o m i t t e d trom t h e sample b e c a u s e t h e y t o o k m e d i c a t i o n a t t e r t h e t i m e s p e c i i i e d and t h r e e o t h e r s were o m i t t e d b e c a u s e t h e y were u n a b l e t o d i s t i n g u i s h any ot t h e t o u r s t i m u l u s l e v e l s a d m i n i s t e r e d i n t h e SDT t a s k . A t o t a l ot n i n e t y s u b j e c t s p r o d u c e d v a l i d d a t a , t h i r t y i n e a c h of t h r e e g r o u p s w i t h e q u a l numbers o f m a l e s and f e m a l e s i n e a c h g r o u p . The mean age of t h e e n t i r e sample was 40.3 y e a r s (SD=7.8, range=30-59 y e a r s ) . Of t h e c o n t r o l s u b j e c t s , 30% were m a r r i e d o r i n common-law r e l a t i o n s h i p s , i n c o n t r a s t t o t h e p a i n p a t i e n t s o f whom 68% were m a r r i e d o r i n v o l v e d i n common-law r e l a t i o n s h i p s . E i g h t y - n i n e p e r c e n t of t h e sample were C a u c a s i a n a n g l o p h o n e s w h i l e 11% r e p o r t e d E n g l i s h as t h e i r s e c o n d l a n g u a g e . S o c i o e c o n o m i c s t a t u s was r a t e d on the B l i s h e n , C a r r o l l , and Moore (1987) i n d e x b a s e d on 1981 c e n s u s d a t a . The mean s o c i o e c o n o m i c i n d e x f o r t h e e n t i r e sample was 43.22 (SD=14.30). S e v e n t y - t w o p e r c e n t were employed and 28% were n o t w o r k i n g . T h i s g r o u p c o n s i s t e d of s t u d e n t s , u n e m p l o y e d p e o p l e s e e k i n g work, and homemakers not s e e k i n g o u t s i d e wo r k. Of t h e p a i n p a t i e n t s , t h e mean s e l f - r e p o r t e d d u r a t i o n of the p a i n c o n d i t i o n was 9.0 y e a r s (SD = 9.3, range=.5-38 y e a r s ' ) . T h i r t y p e r c e n t r e p o r t e d h a v i n g u n d e r g o n e p r e v i o u s s u r g e r y . P h y s i c a l i m p a i r m e n t ( i . e . , o b j e c t i v e s t r u c t u r a l l i m i t a t i o n s ) was a s s e s s e d by t h e p h y s i c i a n s a c c o r d i n g t o c r i t e r i a o u t l i n e d by W a d d e l i and M a i n (1984) w h i c h a r e d e s c r i b e d more t h o r o u g h l y below. The measure y i e l d s a p e r c e n t a g e o f b o d i l y i m p a i r m e n t ( i . e . , l o s s of f u n c t i o n ) . Mean p e r c e n t a g e s f o r the sample ot 44 p a i n p a t i e n t s were 14.3% (SD=5.54) f o r t h e men and 15.36% (SD=8.2) f o r women. S e l f r e p o r t of s u b j e c t i v e d i s a b i l i t y was me a s u r e d by t h e O s w e s t r y D i s a b i l i t y I n v e n t o r y a l s o d e s c r i b e d b elow. Mean p e r c e n t a g e of s u b j e c t i v e d i s a b i l i t y f o r t h e men was 28.56% (SD=12.73) and 38.63% (SD=14.74) f o r t h e women. The above v a l u e s f o r o b j e c t i v e p h y s i c a l i m p a i r m e n t and s u b j e c t i v e d i s a b i l i t y a r e s i m i l a r t o t h o s e o b t a i n e d by R e e s o r and C r a i g (1988) who a s s e s s e d p a i n p a t i e n t s f r o m t h e same f a c i l i t y . M e d i c a t i o n was rank, o r d e r e d a c c o r d i n g t o t h e s t r e n g t h ot e f f e c t on t h e c e n t r a l n e r v o u s s y s t e m (Yang e t a l . , 1 9 8 5 ) . S i x t y f i v e p e r c e n t o f t h e sample d e n i e d t a k i n g m e d i c a t i o n r e g u l a r l y . F i f t e e n p e r c e n t r e p o r t e d t a k i n g n o n n a r c o t i c a n a l g e s i c s o n l y ; 8% r e p o r t e d t a k i n g m e d i c a t i o n w i t h a combined p s y c h o t r o p i c and n o n n a r c o t i c a n a l g e s i c a c t i o n ; and 12% r e p o r t e d t a k i n g o p i a t e a n a l g e s i c m e d i c a t i o n . The p e r c e n t a g e breakdown of t y p e of m e d i c a t i o n f o r t h e sample of p a i n p a t i e n t s i s p r e s e n t e d i n T a b l e 2. Of i n t e r e s t i s t h e a b s e n c e of a n x i o l y t i c o r s e d a t i v e m e d i c a t i o n and t h e p r e p o n d e r a n c e of no m e d i c a t i o n t a k e n f o r a l l f o u r g r o u p s . 45 T a b l e 2 : P e r c e n t a g e of M e d i c a t i o n Use by P a t i e n t Group C o n g r u e n t I n c o n g r u e n t M e d i c a t i o n M a l e s Fema 1 e s Ma 1 e s F ema 1 e s A n t i - i n f l a m m a t o r y/ A n a l g e s i c s M u s c l e R e l a x a n t s O p i a t e A n a l g e s i c s A n t i d e p r e s s a n t s No M e d i c a t i o n n-15 p e r g r o u p P r i m a r y and s e c o n d a r y d i a g n o s t i c c a t e g o r i e s ( a n d / o r e x a c e r b a t i n g f a c t o r s ) , as d e t e r m i n e d by c h a r t r e v i e w , a r e l i s t e d i n T a b l e 3. I t s h o u l d be n o t e d t h a t one of t h e s u b j e c t s was m i s s i n g a p r i m a r y d i a g n o s i s and 15 were not g i v e n s e c o n d a r y d i a g n o s e s . T a b l e 3 . P e r c e n t a g e Breakdown o f D i a g n o s e s i n the P a t i e n t Sample P r i m a r y D i a g n o s e s S e c o n d a r y D i a g n o s e s &/or E x a c e r b a t i n g F a c t o r s No C l e a r F i n d i n g s o r P h y s i c a l D e c o n d i t i o n i n g / P a i n Out o f P r o p o r t i o n I n a c t i v i t y / O b e s i t y 35 . 6 to P a t h o l o g y 25 . 4 F a c e t J o i n t R e l a t e d 1 1 . 1 M e c h a n i c a l Back P a i n 16 . 9 D e g e n e r a t i v e Changes 1 1 . 1 F a c e t J o i n t R e l a t e d 1 6 . 9 D i s c o g e n i c P r o b l e m 6 . 7 D e g e n e r a t i v e D i s c 1 1 . 9 P a i n Out o f P r o p o r t i o n N e r v e Root I r r i t a t i o n 6 . 8 to Pathology- 6 . 7 S o f t T i s s u e I n j u r y 6 . 8 A r t h r i t i s 6 . 7 S p o n d y l o s i s 6 . 8 D e p r e s s i o n / A l c o h o l Abuse 6 . 7 B u r s i t i s / F i b r o s i t i s 3 . 4 S p i n a l S t e n o s i s / S p o n d y l o l i t h e s i s 1 . 7 C a l c i f i c a t i o n 4 . 4 L u m b a r i z a t i o n 1 . 7 M e c h a n i c a l Back P a i n 4 . 4 D i s c P r o t r u s i o n 1 . 7 P s y c h o l o g i c a l O v e r l a y 2 2 N e r v e Root I r r i t a t i o n •) . 2 S o f t T i s s u e I n j u r y 2 2 31.2 18.8 14.3 6.2 0 0 6.2 6.2 6.2 12.5 31.2 14.3 0 0 0 14.3 62.5 56.2 56.2 42.8 n=59 n=4 5 46 Group A s s i g n m e n t The s u b j e c t s f o r m e d t h r e e g r o u p , and two p a i n p a t i e n t g r o a s s i g n e d t o two g r o u p s ( m e d i c a l i n c o n g r u e n t ) on t h e b a s i s o f t h ( W a d d e l i e t a l . , 1980) ( A p p e n d i ( R a n s f o r d e t a l . , 1976) (Append Symptom I n v e n t o r y ( W a d d e l i e t a N o n o r g a n i c p h y s i c a l s i g n s we the Back P a i n C l i n i c . A l t h o r o u t i n e p a r t of the c l i n i c ' s p a i n p a t i e n t s were a s s e s s e d p a t i e n t s , 20 were a s s e s s e d b a l l o w e d f o r t h e c a l c u l a t i o n P e a r s o n c o r r e l a t i o n c o e f f i c i m easure i n d i c a t e d a d e q u a t e i JJ<.00 1) w h i c h i s s i m i l a r t o ( 1 9 8 8 ) . The P a i n D r a w i n g wa ( 1976) s c o r i n g c r i t e r i a . F i d r a w i n g s were s c o r e d by two a f e m a l e r e s e a r c h a s s i s t a n t . ( r = . 9 6 , D<.001) as c a l c u l a t e c o e f f i c i e n t . The I n a p p r o p r i t h e f o r m of an i n t e r v i e w by P a t i e n t s were a s s i g n e d more n o n - o r g a n i c p h y s i c a l s i i n a p p r o p r i a t e symptoms were g r o u p s : a n o r m a l c o n t r o l u p s . P a i n p a t i e n t s were l y c o n g r u e n t o r m e d i c a l l y e N o n o r g a n i c P h y s i c a l S i g n s x A ) , t h e P a i n D r a w i n g i x B ) , and t h e I n a p p r o p r i a t e 1., 1984) ( A p p e n d i x C ) . r e a s s e s s e d D y t h e p h y s i c i a n s i n ugh t h i s measure i s i n c l u d e d as a a s s e s s m e n t , o n l y 44 of t h e 60 on t h i s m e a s u r e . Of t h e s e 44 y two i n d e p e n d e n t p h y s i c i a n s w h i c h of i n t e r r a t e r r e l i a b i l i t y . The e n t on the t o t a l s c o r e on t h i s n t e r r a t e r r e l i a b i l i t y ( r = . 77 , t h a t o b t a i n e d by R e e s o r and C r a i g s s c o r e d u s i n g t h e R a n s f o r d e t a l . f t y f i v e p e r c e n t (n= 3 3) of t h e s e i n d e p e n d e n t r a t e r s , t h e a u t h o r and I n t e r r a t e r r e l i a b i l i t y was h i g h d w i t h a P e a r s o n c o r r e l a t i o n a t e Symptom I n v e n t o r y was g i v e n i n t h e e x p e r i m e n t e r . to t h e i n c o n g r u e n t g r o u p i f 2 or gns were p r e s e n t ; 3 o r more r e p o r t e d ; or p a t i e n t s s c o r e d 5 or 47 g r e a t e r on t h e P a i n D r a w i n g a c c o r d i n g t o t h e R a n s t o r d e t a l . (1976) s c o r i n g s y s t e m . P a i n p a t i e n t s were a s s i g n e d to t h e c o n g r u e n t g r o u p i n the a b s e n c e of t h e s e c r i t e r i a . The p r e c e d e n t f o r t h i s c l a s s i f i c a t i o n s y s t e m was s e t by R e e s o r and C r a i g (1988) who, f r o m a d i s c r i m i n a t e f u n c t i o n a n a l y s i s , r e p o r t e d t h a t 85% o f t h e p a t i e n t s were c o r r e c t l y c l a s s i f i e d a c c o r d i n g t o t h i s s y s t e m . R e e s o r & C r a i g (1988) a s s i g n e d p a t i e n t s t o t h e i n c o n g r u e n t g r o u p i f a t l e a s t one o f t h e t h r e e m e a s u r e s i n d i c a t e d an a b n o r m a l p r e s e n t a t i o n of t h e p a i n i n o r d e r t o keep t h e g r o u p s as d i s t i n c t as p o s s i b l e . A l l t h r e e m e a s u r e s i n d i c a t e e x a g g e r a t e d symptom r e p o r t or p a i n p r e s e n t a t i o n but i n v o l v e t h r e e d i f f e r e n t modes o f c o m m u n i c a t i o n : b e h a v i o r a l , v e r b a l r e p o r t , and p i c t o r a l . The t h r e e m e a s u r e s have been f o u n d t o be m o d e r a t e l y c o r r e l a t e d ( R e e s o r & C r a i g , 1 9 8 8 ) . The r e l a t i o n s h i p s among t h e s e t h r e e m e a s u r e s i n t h e p r e s e n t s t u d y a r e p r e s e n t e d i n T a b l e 4 . T a b l e 4 : R e l a t i o n s h i p s Among M e a s u r e s o f I n c o n g r u e n t P a i n M e asure N o n - o r g a n i c I n a p p r o p r i a t e P a i n S i g n s Symptoms D r a w i n g N o n - o r g a n i c S i g n s I n a p p r o p r i a t e Symptoms -15 ( 44 ) P a i n D r a wing S c o r e . 4 3 * . 4 1 ) * * ( 4 4 ) (60) * p <.01 ; * * p < . 0 0 1 Of n o t e , t h e N o n - o r g a n i c P h y s i c a l S i g n s were m o d e r a t e l y c o r r e l a t e d w i t h the P a i n D r a w i n g but were not s i g n i f i c a n t l y c o r r e l a t e d w i t h the I n a p p r o p r i a t e Symptom I n v e n t o r y . The P a i n 48 D r a w i n g and I n a p p r o p r i a t e Svmptoms were m o d e r a t e l v c o r r e l a t e d . T a b l e 5 l i s t s t h e p e r c e n t a g e o c c u r r e n c e ot p a t i e n t s e x c e e d i n g e a c h c r i t e r i o n w i t h i n t h e m e d i c a l l y i n c o n g r u e n t g r o u p by s e x . T a b l e 5: P e r c e n t a g e O c c u r r e n c e of C r i t e r i a W i t h i n t h e I n c o n g r u e n t Group Sex N o n - o r g a n i c I n a p p r o p r i a t e P a i n D r a wing S i g n s (>1) Symptoms (>2) S c o r e ( >4 ) M a l e s 13 73 40 F e m a l e s 33 80 73 n= l 5 T a b l e 6 r e p r e s e n t s t h e p e r c e n t a g e of p a i n p a t i e n t s i n t h e m e d i c a l l y i n c o n g r u e n t g r o u p who s a t i s f i e d one, two, or t h r e e of t h e c r i t e r i a . O n l y t h o s e p a t i e n t s f o r whom a l l t h r e e m e a s u r e s were a v a i l a b l e a r e i n c l u d e d . V e r y few of t h e s u b j e c t s met a l l t h r e e c r i t e r i a b u t , as i n R e e s o r and C r a i g ' s d a t a , more women t h a n men met two of the t h r e e c r i t e r i a . None of t h e p a t i e n t s were c l a s s i f i e d as i n c o n g r u e n t on t h e b a s i s of th e n o n o r g a n i c p h y s i c a l s i g n s o n l y . Of t h o s e i d e n t i f i e d by- o n l y one o f t h e t h r e e c r i t e r i a , s e v e n were c l a s s i f i e d as ' m e d i c a l l y i n c o n g r u e n t ' on t h e b a s i s of t h e i n a p p r o p r i a t e symptoms, and one on t h e b a s i s of t h e p a i n d r a w i n g . 49 T a b i c fa: P e r c e n t a g e ot P a t i e n t s M e e t i n g I n c o n g r u e n t C r i t e r i a Number ot C r i t e r i a Sex T h r e e Two One M a l e s 0 25 75 F e m a l e s 15 69 15 ( M a l e s , n=8; F e m a l e s , n=13) E q u i p m e n t R a d i a n t h e a t was d e l i v e r D o l o r i m e t e r ( W i l l i a m s o n D e v e l c a l i b r a t e d u s i n g a F i s c h e r Sc S t i m u l i were a d m i n i s t e r e d t o p a t c h e s o f i n d i a ink. a p p l i e d f o r e a r m ( f o u r on e a c h a r m ) . ed by a H a r d y - W o l f f - G o o d e 1 1 opment C o . ) . The d o l o r i m e t e r was i e n t i f i c D i g i t a l T h e r m o p r o b e . one of e i g h t 2.0 cm d i a m e t e r to t h e v o l a r s u r f a c e of e a c h S t i m u 1 i The s t i m u l i s e l e c t e d f o r the SDT e x p e r i m e n t were d e t e r m i n e d i n a p i l o t s t u d y i n v o l v i n g a g r o u p of 20 n o r m a l s u b j e c t s ( i . e . , n o n - p a i n p a t i e n t s ) , age and sex matched t o the g r o u p s u s e d i n t h e SDT e x p e r i m e n t . T h e s e s u b j e c t s were r e c r u i t e d f r o m t h e s t a f f o f t h e S h a u g h n e s s y H o s p i t a l and were p a i d $5.00 f o r t h e i r p a r t i c i p a t i o n . A f t e r c o m p l e t i n g t h e c o n s e n t f o r m ( A p p e n d i x D ) , f a i n t p a i n t h r e s h o l d t o r a d i a n t h e a t was d e t e r m i n e d by a s t a i r c a s e method of t h r e s h o l d 50 d e t e r m i n a t i o n . F a i n t p a i n t h r e s h o l d r e f e r s t o the l e v e l of s t i m u l a t i o n a t w h i c h a " d i s t i n c t , s h a r p , v e r y s m a l l s t a b o f p a i n ( i s ) e x p e r i e n c e d a t t h e e x a c t end of a t h r e e s e c o n d e x p o s u r e t o t h e s t i m u l u s " ( H a r d y , W o l f f , & G o o d e l l , 1952, p. 8 1 ) . H a r d y , W o l f f , and G o o d e l l (1952) r e p o r t e d t h a t the t h r e s h o l d f o r t h i s s e n s a t i o n , c a l l e d " p r i c k i n g p a i n " i s e a s i l y i d e n t i f i e d . The s t a i r c a s e method u s e d i s c a l l e d t h e "Up-Down Meth o d " ( D i x o n & M assey, 1969) and p r o v i d e s a f a s t and a c c u r a t e e s t i m a t e of t h r e s h o l d . B r i e f l y , i t i n v o l v e s i n c r e a s i n g t h e s t i m u l u s i n t e n s i t y i n 10 m c a l / s e c / c m u n i t i n c r e m e n t s u n t i l p a i n i s r e p o r t e d . The i n t e n s i t y of t h e s t i m u l u s i s t h e n d e c r e a s e d u n t i l no p a i n i s r e p o r t e d . The d i r e c t i o n i n w h i c h th e i n t e n s i t y of t h e s t i m u l u s c h a n g e s c o n t i n u e s i n t h i s manner u n t i l s i x t r i a l s a f t e r t h e f i r s t r e v e r s a l a r e r e c o r d e d . Based on t h e f i n a l i n t e n s i t y l e v e l a d m i n i s t e r e d and t h e p a t t e r n o f r e s p o n d i n g , an a c c u r a t e e s t i m a t e of p a i n t h r e s h o l d c a n be c a l c u l a t e d . T h r e s h o l d s were d e t e r m i n e d a f t e r s u b j e c t s had been f a m i l i a r i z e d w i t h t h e r a n g e of s t i m u l i and t h e l e v e l of s t i m u l a t i o n t h a t t h e y r e p o r t e d t o be f a i n t l y p a i n f u l . The mean f a i n t p a i n t h r e s h o l d was 253.14 m c a l / s e c / c m - ( S D = 2 6 . 5 0 , r a n g e = 2 1 5 . 0 - 3 0 2 . 5 ) . T h e r e was no s i g n i f i c a n t d i f f e r e n c e between m a l e s and f e m a l e s (J^=.02, p>.05). On t h e b a s i s o f t h i s a v e r a g e t h r e s h o l d and t h e r a n g e , f o u r s t i m u l i were s e l e c t e d f o r t h e SDT e x p e r i m e n t w h i c h were a d m i n i s t e r e d t o a l l s u b j e c t s . T h e s e f o u r s t i m u l i s p a n n e d the a v e r a g e ' n o r m a l ' p a i n t h r e s h o l d s u c h t h a t two were above and two below i n 51 a d d i t i o n t o e n c o m p a s s i n g the r a n g e . S t i m u l i i n t e n s i t i e s were 2 s p a c e d a t e q u a l i n t e r v a l s (30 mcal/sec/cm*" a p a r t ) and were: 210, 240, 270, and 300 m c a l / s e c / c m " . T h i s was t o i n c r e a s e t h e l i k e l i h o o d t h a t t h e p a i n t h r e s h o l d w o u l d be s p a n n e d by t h e s e f o u r s t i m u l i f o r a l l t h e s u b j e c t s . H a r d y , W o l f f , and G o o d e l l ( 1952) r e p o r t e d t h a t t h e j u s t n o t i c e a b l e d i f f e r e n c e t o r 2 p r i c k i n g p a i n i s 7 m c a l / s e c / c m on a v e r a g e . P r o c e d u r e The Back P a i n C l i n i c c o n d u c t s t h e i r a s s e s s m e n t o v e r two c o n s e c u t i v e d a y s . D u r i n g t h e f i r s t day of a s s e s s m e n t , e l i g i b l e p a t i e n t s were i n f o r m e d a b o u t t h e s t u d y and r e q u i r e m e n t s and a s k e d i f t h e y would be w i l l i n g t o p a r t i c i p a t e d u r i n g t h e s e c o n d day of t h e i r a s s e s s m e n t . T h o s e who a g r e e d were g i v e n t h e c o n s e n t f o r m ( A p p e n d i x E) and a s k e d t o r e t u r n i t when t h e y t o o k p a r t i n t h e s t u d y t h e f o l l o w i n g day. D u r i n g t h e one h o u r e x p e r i m e n t , s u b j e c t s underwent the same s e r i e s o f e v e n t s . F i r s t , i n d i a i n k was u s e d t o p a i n t f o u r , 2 cm d i a m e t e r s p o t s on t h e v o l a r s u r f a c e of e a c h f o r e a r m . W h i l e t h e s e d r i e d , s u b j e c t s c o m p l e t e d t h e s e l f - r e p o r t q u e s t i o n n a i r e s . D e m o g r a p h i c i n f o r m a t i o n and i n f o r m a t i o n r e l a t e d t o t h e i r p a i n c o n d i t i o n was t h e n c o l l e c t e d , f o l l o w e d by t h e I n a p p r o p r i a t e Symptom I n v e n t o r y w h i c h was g i v e n i n t h e f o r m o f an i n t e r v i e w . W h i l e th e i n s t r u c t i o n s f o r t h e p a i n p e r c e p t i o n t a s k ( A p p e n d i x F) were r e a d , t h e s u b j e c t ' s s k i n t e m p e r a t u r e was t a k e n . 52 A t t e r h e a r i n g the i n s t r u c t i o n s , a l l s u b j e c t s were g i v e n an a s c e n d i n g s e r i e s ot s t i m u l i and were a s k e d t o v e r b a l l y d e s c r i b e t h e s e n s a t i o n s t h e y were e x p e r i e n c i n g . When t h e y i d e n t i f i e d t h e p o i n t a t w h i c h a f a i n t p r i c k l y s e n s a t i o n was p e r c e i v e d , i t was e m p h a s i z e d t o them t h a t t h i s was t h e ' s i g n a l ' t h a t we wanted them t o d e t e c t . I t was s t r e s s e d t h a t t h e y were r e q u i r e d t o d i s t i n g u i s h between h e a t and t h e f i r s t h i n t o f a p r i c k l y s e n s a t i o n w h i c h i s c o n s i d e r e d t o be t h e b e g i n n i n g of p a i n . S e v e r a l more r a n d o m l y p r e s e n t e d s t i m u l i i n t e n s i t i e s were p r e s e n t e d a r o u n d t h e r e p o r t e d f a i n t p a i n l e v e l u n t i l t h e s u b j e c t r e s p o n d e d i n a r e l a t i v e l y c o n s i s t e n t f a s h i o n and had c o n f i d en ce t h a t t h e y knew what t h e y were t r y i n g t o d e t e c t . T h r e s h o l d f o r f a i n t p a i n was t h e n d e t e r m i n e d f o r e a c h s u b j e c t u s i n g t h e Up-Down.Method t h a t was u s e d i n t h e p i l o t s t u d y . T h i s was f o l l o w e d by t h e s i g n a l d e t e c t i o n e x p e r i m e n t of w h i c h t h e f o u r s t i m u l u s l e v e l s s e l e c t e d ( 2 1 0 , 240, 270, and 2 300 mcal/sec/cm*") f r o m t h e p i l o t s t u d y were a d m i n i s t e r e d i n 10 random b l o c k s of e i g h t s t i m u l i e a c h . Twenty t r i a l s were a d m i n i s t e r e d f o r e a c h s t i m u l u s i n t e n s i t y making a t o t a l of 80 e x p e r i m e n t a l t r i a l s . P r i o r t o t h e a d m i n i s t r a t i o n of the e x p e r i m e n t a l t r i a l s , 4 p r a c t i c e t r i a l s per s t i m u l u s i n t e n s i t y were a d m i n i s t e r e d making a t o t a l of 16 p r a c t i c e t r i a l s ( A p p e n d i x G ) . The d u r a t i o n o f e a c h s t i m u l u s was 3 s e c o n d s w i t h a 12 s e c o n d i n t e r s t i m u l u s i n t e r v a l and s u b j e c t s were t o l d t o move th e h e a t gun t o a d i f f e r e n t s p o t f o r e a c h t r i a l , t h u s r o t a t i n g among th e e i g h t l o c a t i o n s on t h e f o r e a r m s . On e a c h 53 t r i a l , s u b j e c t s were r e q u i r e d t o make a b i n a r y d e c i s i o n as t o w h e t h e r t h e y f e l t p a i n o r n o t . A p p r o x i m a t e t i m e t o c o m p l e t e e x p o s u r e t o t h e s t i m u l i i n t h e SDT t a s k was 3 0 m i n u t e s . Upon t h e c o m p l e t i o n o f t h e p a i n p e r c e p t i o n t a s k , s u b j e c t s r a t e d t h e most i n t e n s e s t i m u l u s r e c e i v e d d u r i n g t h e e x p e r i m e n t on t h e G r a c e l y R a t i n g S c a l e s o f s e n s o r y i n t e n s i t y and u n p l e a s a n t n e s s . F i n a l l y , s u b j e c t s were t h o r o u g h l y d e b r i e f e d ( A p p e n d i x H) and p a i d $20.00 f o r t h e i r p a r t i c i p a t i o n . The P a i n D r a w i n g and A s s e s s m e n t of N o n o r g a n i c P h y s i c a l S i g n s were a d m i n i s t e r e d by t h e Back P a i n C l i n i c S t a f f d u r i n g t h e two day a s s e s s m e n t . The Normal C o n t r o l Group underwent the same s e r i e s o f e v e n t s e x c e p t t h e y d i d n o t c o m p l e t e any i n f o r m a t i o n r e l e v a n t t o c h r o n i c p a i n c o n d i t i o n s ( c o n s e n t f o r m , A p p e n d i x I ) . The a u t h o r a s s e s s e d 25 s u b j e c t s w h i l e a f e m a l e r e s e a r c h a s s i s t a n t t h o r o u g h l y t r a i n e d i n t h e e x p e r i m e n t a l p r o c e d u r e s a s s e s s e d 35. T h e r e were no s y s t e m a t i c d i f f e r e n c e s between the d a t a c o l l e c t e d by e a c h e x p e r i m e n t e r as a s s e s s e d by t - t e s t s on' t h e means of p a i n t h r e s h o l d and t h e s i g n a l d e t e c t i o n i n d i c e s . SDT M e a s u r e s o f D i s c r i m i n a b i l i t y and R e s p o n s e B i a s I n i t i a l l y , the a v e r a g e p a i n t h r e s h o l d f o r t h e n o n p a t i e n t sample i n t h e p i l o t s t u d y was u s e d as t h e c u t o f f p o i n t f o r d e s i g n a t i n g ' h i t s ' and ' f a l s e a l a r m s ' . By d e s i g n , the s t u d y i n c l u d e d two s t i m u l u s i n t e n s i t i e s above t h i s t h r e s h o l d and two b e l o w . S t i m u l i j u d g e d t o be ' p a i n f u l ' above t h i s l e v e l were c a l l e d ' h i t s ' and t h o s e j u d g e d t o be ' p a i n f u l ' below t h i s 54 l e v e l were c o n s i d e r e d to be ' t a l s e a l a r m s ' . Two a d d i t i o n a l c u t o t t s were s e t t o r the d e t i n i t i o n ot ' h i t s ' and ' t a l s e a l a r m s ' i n o r d e r to c a l c u l a t e , a l o n g w i t h the o r i g i n a l d' and b e t a m e a s u r e s , t h r e e s e n a r a t e measures t o r d' and b e t a . The two a d d i t i o n a l c u t o t t s were between the l o w e s t s t i m u l u s l e v e l and the o t h e r t h r e e s t i m u l i l e v e l s and t h e h i g h e s t s t i m u l u s l e v e l and t h e lower t h r e e . A g a i n , s t i m u l i judged to be D a i n i u l t h a t were above a s p e c i t i e d c u t o t t were c o n s i d e r e d to be ' h i t s ' and s t i m u l i judged t o be p a i n t u l t h a t were below the c u t o t t were c o n s i d e r e d to be ' t a l s e a l a r m s ' . These measures were t h e n a v e r a g e d to o r o d u c e one d' and b e t a measure t o r each s u b j e c t . By t h i s method, the r e s u l t i n g a v e r a g e d measures were more s t a b l e ( i . e . l e s s skewed and l e s s s p r e a d o u t ) t h a n anv ot the t h r e e measures by t h e m s e l v e s . G i v e n t h a t the p u r p o s e ot t h i s s t u d v was to a s s e s s the r e l a t i v e judgements ot p a i n t u l s t i m u l i b v c h r o n i c p a i n p a t i e n t s vs c o n t r o l s u b j e c t s , i t was p o s s i b l e to c o n s i s t e n t l y s p e c i t y the p r e s e n c e or a b s e n c e ot a s i g n a l on the b a s i s ot the c o m p a r i s o n g r o u p . T h i s r e p r e s e n t s an i m p o r t a n t m e t h o d o l o g i c a l i n n o v a t i o n i n the a p p l i c a t i o n ot SDT t o p a i n r e s e a r c h . The use ot t h i s method, w h i c h s e t s a t i x e d c o m p a r i s o n l e v e l Cor b a s e l i n e ) on the b a s i s ot the c o i o a r i s o n g r o u p , c o n t o r m s e x a c t l y to the a s s u m p t i o n s and r e q u i r e m e n t s ot a SDT t a s k . T h i s a l l o w s t o r the unambiguous i n t e r p r e t a t i o n ot / the d's and b e t a s i n a manner not r e a l l v p o s s i b l e i n p a s t SDT i n v e s t i g a t i o n s ot o a i n . 55 Because the j u d g ements ot the s t i m u l i a r e r e l a t i v e to s e t c u t o t t D o i n t s , t h e a v e r a g e d d' measure i s i n t e r p r e t a b 1 e i n terms ot the c o n s i s t e n c y ot judgements made. The h i g h e r the d' measure, the more c o n s i s t e n t the judgements were. C o n s i s t e n c v i n judgements i s a r e t l e c t i o n ot how w e l l the s u b j e c t was a b l e to d i s t i n g u i s h or d i s c r i m i n a t e between heat and the t i r s t t r a c e ot p a i n . Because s t i m u l i l e v e l s and i n s t r u c t i o n s to s u b j e c t s were h e l d c o n s t a n t i n t h i s i n v e s t i g a t i o n , t h e a b i l i t y to c o n s i s t e n t l y d i s t i n g u i s h h e a t trom t a i n t p a i n i s i n t e r p r e t e d to r e t l e c t g r e a t e r s e n s i t i v i t y to d i t t e r e n c e s i n s t i m u l u s l e v e l s or to d e t e c t the t i r s t t r a c e ot p a i n upon a b a c k g r o u n d ot s e n s o r y n o i s e ( i . e . , h e a t ) . The c r i t e r i o n , b e t a , r e f l e c t s the t e n d e n c y t o r e p o r t p a i n s e n s a t i o n s such t h a t the lower the c r i t e r i o n s e t , the l e s s s t i m u l a t i o n needed to c a l l the s t i m u l u s p a i n t u l . M e a s ures ot Impairment and D i s a b i l i t y 1) The P h y s i c a l Impairment Index ( W a d d e l l & Main, 1984) (Append i x J ) . P h v s i c a l i m p a i r m e n t r e f e r s to o b j e c t i v e s t r u c t u r a l l i m i t a t i o n s or l o s s ot a b i l i t y b e cause ot a n a t o m i c a l or p a t h o p h y s i o l o g i c a l a b n o r m a l i t y . The measure p r o v i d e s a p e r c e n t a g e ot p h y s i c a l impairment which i s based o n o b j e c t i v e e v i d e n c e i n c l u d i n g the p a i n p a t t e r n , time p a t t e r n , p r e s e n c e ot a p r e v i o u s t r a c t u r e , p r e v i o u s s u r g e r y , s i g n s ot r o o t c o m p r e s s i o n , and s t r a i g h t l e g r a i s i n g b o t h w i t h and w i t h o u t d i s t r a c t i o n . T h i s c o m b i n a t i o n ot p h y s i c a l c h a r a c t e r i s t i c s was 56 s e l e c t e d bv W a d d e l i and Main (1984) f o l l o w i n g a r e g r e s s i o n a n a l v s i s w hich i d e n t i i i e d them as y i e l d i n g the b e s t p r e d i c t i o n ot i m p a i r m e n t . I n t e r r a t e r r e l i a b i l i t y t o r each ot the i c h a r a c t e r i s t i c s r a n g e d trom 77 t o 100% agreement ( M a i n & W a d d e l i , 1984). T h i s measure was c o m p l e t e d bv two i n d e p e n d e n t e x a m i n e r s i n the p r e s e n t s t u d y on 41% ot the p a t i e n t sample (n=11). I n t e r r a t e r r e l i a b i l i t y was h i g h ( j r=.94) as c a l c u l a t e d on the o v e r a l l t o t a l s c o r e s u s i n g a P e a r s o n c o r r e l a t i o n c o e t t i c i e n t . T h i s l e v e l ot i n t e r r a t e r r e l i a b i l i t y was t h e same as t h a t r e p o r t e d by R e e s o r & C r a i g ( 1988). 2) The O s w e s t r v Low Back. P a i n D i s a b i l i t y Q u e s t i o n n a i r e ( F a i r b a n k , C o u p e r , D a v i e s , and O ' B r i e n , 1980) ( A p p e n d i x K ) . D i s a b i l i t y r e t e r s t o the s u b j e c t i v e r e p o r t ot l o s s ot t u n c t i o n due t o a back p a i n p r o b l e m . T h i s s e l t r e p o r t i n v e n t o r y a s s e s s e s t h e e x t e n t to w h i c h e v e r y d a y a c t i v i t i e s a r e compromised bv the p a t i e n t ' s back p a i n p r o b l e m . I t c o n s i s t s ot t e n s e p a r a t e s c a l e s w h i c h a s s e s s d i t t e r e n t a r e a s ot e v e r y d a y l i v i n g i n c l u d i n g : need t o r a n a l g e s i c m e d i c a t i o n , p e r s o n a l c a r e , l i t t i n g , w a l k i n g , s i t t i n g , s t a n d i n g , s l e e p i n g , s e x u a l a c t i v i t y , s o c i a l l i t e , and t r a v e l l i n g . P a t i e n t s e n d o r s e one ot s i x s t a t e m e n t s i n each a r e a r e f l e c t i n g i n c r e a s i n g l e v e l s ot d i s a b i l i t y . The i n v e n t o r y i s s c o r e d to v i e l d a p e r c e n t a g e ot s e l t r e p o r t e d d i s a b i l i t y . T h i s measure has been tound t o r e f l e c t r e c o v e r y trom an a c u t e back p a i n p r o b l e m and to be s t a b l e ( i . e . , t e s t - r e t e s t 57 r e l i a b i l i t y , j r=.99) i n c h r o n i c c o n d i t i o n s ( F a i r b a n l ; c t a l . , 1980). Reesor (1990) r e p o r t e d the Oswestry to d i s c r i m i n a t e e x t e n s i v e from moderate or m i n i m a l back p a i n . The measure has been d e m o n s t r a t e d t o have i n t e r n a l c o n s i s t e n c y ( F a i r b a n k et a l . , 1980) . Main and W a d d e l l (1984) have s u g g e s t e d t h a t o b j e c t i v e p h y s i c a l impairment and s u b j e c t i v e d i s a b i l i t y can be compared. They r e p o r t e d t h a t p h y s i c a l i m p a i r m e n t a c c o u n t s f o r l e s s than h a l f of the r e p o r t e d d i s a b i l i t y which a l s o i n c l u d e s p s y c h o l o g i c a l f a c t o r s i n v o l v e d i n c h r o n i c p a i n . S e l f R e p o r t Measures 1) The G r a c e l y R a t i n g S c a l e ( G r a c e l y , Dubner, & M c G r a t h , 1979) ( A p p e n d i x L ) . S u b j e c t s r a t e d the most p a i n f u l s t i m u l i as t o i t s s e n s o r y i n t e n s i t y and u n p l e a s a n t n e s s on the G r a c e l y R a t i n g S c a l e r e t r o s p e c t i v e to t h e a d m i n i s t r a t i o n of a l l the s t i m u l i . Each s c a l e has 13 d e s c r i p t o r s t h a t have been q u a n t i f i e d i n t h e form of r a t i o s c a l e s and f o r w h i c h r e l i a b i l i t y and v a l i d i t y have been d e m o n s t r a t e d ( G r a c e l y e t a l . , 1979). These s c a l e s have been p r e f e r r e d o v e r o t h e r t y p e s of r a t i n g s c a l e s b e c a u s e of t h e i r p s y c h o p h y s i c a l p r o p e r t i e s (Chapman et a l . , 1985). / 58 2) T h e C o p i n g s t r a t e g y Q u e s t i o n n a i r e ( R o s e n s t e i l & K e e f e , 1 9 8 3 ) ( A p p e n d i x M). T h i s i s a 42 i t e m q u e s t i o n n a i r e t h a t a s s e s s e s t h e f r e q u e n c y t h a t p a t i e n t s r e p o r t u s i n g o n e o f s e v e n s t r a t e g i e s t o c o p e w i t h p a i n : d i v e r t i n g a t t e n t i o n , c o p i n g s e l f - s t a t e m e n t s , p r a y i n g o r h o p i n g , i n c r e a s i n g b e h a v i o r a l a c t i v i t i e s , r e i n t e r p r e t i n g t h e p a i n s e n s a t i o n s , i g n o r i n g t h e p a i n s e n s a t i o n s , a n d c a t a s t r o p h i z i n g . T h e r e a r e a l s o two m e a s u r e s o f c o p i n g s t r a t e g y e f f i c a c y : a b i l i t y t o d e c r e a s e p a i n a n d a b i l i t y t o c o n t r o l p a i n . T h e r e i s h i g h i n t e r - i t e m c o r r e l a t i o n ( a l p h a c o e f f i c i e n t = .71 - .85) i n d i c a t i n g t h a t t h e t e s t i s i n t e r n a l l y r e l i a b l e ( R o s e n s t i e l & K e e f e , 1 9 8 3 ) . T h e f a c t o r s t r u c t u r e o f t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e h a s b e e n c r o s s v a l i d a t e d o n f i v e d i f f e r e n t c h r o n i c p a i n p a t i e n t s a m p l e s ( t o t a l n = 6 2 0 ) ( L a w s o n e t a l . , 1 9 9 0 ) . F r o m t h i s i n v e s t i g a t i o n , a t h r e e f a c t o r s t r u c t u r e o f c o g n i t i v e c o p i n g s t r a t e g i e s was r e c o m m e n d e d . T h e f i r s t c o m p o n e n t i d e n t i f i e d i n c l u d e s t h e f o l l o w i n g s c a l e s : i g n o r i n g p a i n s e n s a t i o n s , c o p i n g s e l f s t a t e m e n t s , a n d r e i n t e r p r e t i n g p a i n s e n s a t i o n s . I t was c h a r a c t e r i z e d a s r e f l e c t i n g a c o n s c i o u s , a c t i v e u s e o f c o g n i t i v e s t r a t e g i e s o r c o p i n g " p r o c e s s e s " t o m a n age p a i n . T h e s e c o n d d i m e n s i o n i d e n t i f i e d r e f e r s t o a s e 1 f - e v a 1 u a t i v e c o m p o n e n t c o n s i s t i n g o f t h e p a t i e n t s ' r a t i n g s o f t h e i r a b i l i t i e s t o c o n t r o l a n d d e c r e a s e t h e p a i n . T h e / t h i r d f a c t o r r e p r e s e n t s s c a l e s r e f l e c t i n g p a s s i v e s t y l e s o f c o p i n g a n d r e l a t e t o t h e s p e c i f i c c o g n i t i v e c o n t e n t o f t h e c o p i n g s t r a t e g i e s ( i . e . , p r a y i n g , h o p i n g , a n d d i v e r t i n g 5 9 a t t e n t i o n to o t h e r m a t t e r s such as m e n t a l games, m u s i c , b o o k s ) . I t was recommended t h a t two s c a l e s be t r e a t e d as s e p a r a t e measures s i n c e t h e v were not c o n s i s t e n t l y r e l a t e d to the above t h r e e t a c t o r s . Thev a r e the s c a l e a s s e s s i n g b e h a v i o u r a l c o p i n g s t r a t e g i e s , w hich i s not s u r p r i s i n g s i n c e t h e s e r e a l l v c annot be c h a r a c t e r i z e d as c o g n i t i v e c o n s t r u c t s as s u c h , and c a t a s t r o p h i z i n g which i s c h a r a c t e r i z e d as b e i n g more r e t l e c t i v e ot e m o t i o n a l t a c t o r s (Lawson et a l . , 1990). The c a t a s t r o p h i z i n g s c a l e has been t o u n d to be r e l a t e d t o the e m o t i o n a l and b e h a v i o u r a l a d j u s t m e n t t o p a i n i n c h r o n i c p a i n c o n d i t i o n s ( K e e f e & D o l a n , 1986; K e e f e et a l . , 1987; 1989; R e e s o r & C r a i g , 1988; R o s e n t i e l & K e e f e , 1983; and T u r n e r & C l a n c e y , 1 9 8 6 ) . 3) The P a i n E x p e r i e n c e S c a l e ( T u r k & Rudy, 1985) ( A p p e n d i x N ) . T h i s i s a 19 i t e m s e l f - r e p o r t i n v e n t o r y d e s i g n e d t o a s s e s s t h e c o g n i t i v e - e v a 1 u a t i v e r e a c t i o n to c h r o n i c p a i n . F a c t o r a n a l y s i s has r e v e a l e d two r e l i a b l e s c a l e s : an e m o t i o n a l i t y s c a l e ( a l p h a = .91, p<.001) r e p r e s e n t i n g d i s t r e s s about t h e p a i n ( e . g . , " T h i s p a i n i s d r i v i n g me c r a z y " ) and a worry s c a l e ( a l p h a = .74, p<.001) r e p r e s e n t i n g l o n g term c o n c e r n s about ^how the p a i n i s a f f e c t i n g the p a t i e n t ' s l i f e ( e . g . , " I worry about my f a m i l y " ) . T e s t - r e t e s t r e l i a b i l i t y (two week i n t e r v a l ) i s h i g h ( r =.89, p. <.001 and r =.81,, p<.001 f o r each s c a l e r e s p e c t i v e l y ) and the s c a l e s a r e s e n s i t i v e t o c o g n i t i v e - b e h a v i o r a 1 t r e a t m e n t . 60 4) The S t a t e - T r a i t A n x i e t y I n v e n t o r y ( S p i e l b e r g e r , 1985) ( A p p e n d i x 0 ) . Onl v the ' T r a i t ' p o r t i o n of t h i s measure was a d m i n i s t e r e d . T h i s s e l f - r e p o r t i n v e n t o r y c o n s i s t s of 2U s t a t e m e n t s to a s s e s s the d e g r e e to w h i c h t h e r e s p o n d e n t i s a n x i e t v p r o n e . The s u b j e c t i n d i c a t e s t h e d e g r e e to which each s t a t e m e n t i s an a c c u r a t e d e s c r i p t i o n of h i m / h e r s e l f . The s c a l e has h i g h i n t e r n a l c o n s i s t e n c y , t e s t - r e t e s t r e l i a b i l i t y , and c o n s t r u c t v a l i d i t y and i s c o n s i d e r e d t o be an e x c e l l e n t measure of t r a i t a n x i e t y ( B u r o s , 1978). S t a t i s t i c a l A n a l y s i s . D e m ographic v a r i a b l e s w h i c h were c o n t i n u o u s i n n a t u r e (age and s o c i o e c o n o m i c s t a t u s ) and t e s t i n g c o n d i t i o n s (room t e m p e r a t u r e d u r i n g t e s t i n g and s k i n t e m p e r a t u r e of each s u b j e c t ) were a n a l y s e d f i r s t u s i n g 3 X 2 ( g r o u p X sex) ANOVAs. C a t e g o r i c a l d e m o g r a p h i c v a r i a b l e s ( m a r i t a l s t a t u s , e t h n i c i t y , and employment s t a t u s ) were a n a l y s e d s e p a r a t e l y u s i n g C h i Square s t a t i s t i c s . T h i s was f o l l o w e d by an a n a l y s i s of p a t i e n t c h a r a c t e r i s t i c s . C a t e g o r i c a l d a t a ( p r e s e n c e or abs e n c e of p r e v i o u s s u r g e r y ) was a g a i n a n a l y s e d u s i n g n o n p a r a m e t r i c s t a t i s t i c s . I n t e r v a l d a t a ( d u r a t i o n ô f the p a i n c o n d i t i o n , s t r e n g t h of a n a l g e s i c m e d i c a t i o n , p e r c e n t a g e of p h y s i c a l i m p a i r m e n t , and p e r c e n t a g e of s u b j e c t i v e d i s a b i l i t y ) were a n a l v s e d u s i n g 2 X 2 ( p a i n group by s e x ) ANOVAs. Dependent measures were d i v i d e d c o n c e p t u a l l y i n t o t h r e e g r o u p s : p a i n , c o g n i t i v e , and a f f e c t i v e m e a s u r e s . The p a i n measures were a n a l y s e d as f o l l o w s : f i r s t , the e n t i r e p a t i e n t group (n=60) was compared to the c o n t r o l group (n=30) on p a i n measures i n 2 X 2 ( g r o u p by sex) a n a l y s e s of v a r i a n c e . Then the p a t i e n t s were a n a l y s e d as s e p a r a t e g r o u p s a c c o r d i n g to the ' c o n g r u e n t / i n c o n g r u e n t ' d i s t i n c t i o n w i t h the c o n t r o l group i n 3 X 2 ( g r o u p by s e x ) a n a l y s e s of v a r i a n c e . In the above a n a l y s e s , p a i n t h r e s h o l d was a n a l y s e d s e D a r a t e l v i n an ANOVA because i t was a s s e s s e d on a s e p a r a t e s e t of s t i m u l i . In a d d i t i o n , i t i s c o n s i d e r e d to be r e d u n d a n t w i t h the s i g n a l d e t e c t i o n m easures, d* and b e t a ( C l a r k , 1987). The r e m a i n i n g p a i n measures were a l l d e r i v e d from the same s e t of s t i m u l i and were, t h e r e f o r e , e n t e r e d i n t o m u l t i v a r i a t e a n a l y s e s . The G r a c e l y R a t i n g S c a l e s of S e n s o r y I n t e n s i t y and U n p l e a s a n t n e s s were f i r s t c o n v e r t e d to z - s c o r e s and a v e r a g e d as t h e y were h i g h l y c o r r e l a t e d (jr=.58, p_<.001) to p r o d u c e a c o m p o s i t e measure of ' s u b j e c t i v e p a i n r a t i n g ' . The SDT i n d i c e s , , d' and b e t a , c a l c u l a t e d r e l a t i v e t o the mean p a i n t h r e s h o l d of the normal c o n t r o l sample, were e n t e r e d i n t o a MANOVA a l o n g w i t h the s u b j e c t i v e p a i n r a t i n g and were f o l l o w e d up by u n i v a r i a t e a n a l y s e s where a p p r o p r i a t e . The mean of the t h r e e d' and b e t a measures were a n a l y z e d s i m i l a r l y . ^ h e f i v e c o g n i t i v e v a r i a b l e s ( c o g n i t i v e p r o c e s s e s , c o g n i t i v e c o n t e n t , s e 1 f - e f f i c a c y , b e h a v i o u r a l c o p i n g s t r a t e g i e s , and c a t a s t r o p h i z i n g ) were a l l d e r i v e d from the same q u e s t i o n n a i r e , the C o p i n g S t r a t e g y Q u e s t i o n n a i r e . These 62 t i v e v a r i a b l e s were e n t e r e d i n t o a 2 X 2 ( p a i n group bv sex) MANOVA which was f o l l o w e d by u n i v a r i a t e a n a l y s e s . The a t i e c t i v e v a r i a b l e s were a n a l y s e d i n t h r e e s e p a r a t e ANOVAs. T h i s was b e c a u s e one of the measures (The S t a t e - T r a i t A n x i e t v I n v e n t o r y ) was a d m i n i s t e r e d to a l l t h r e e g r o u p s and the P a i n E x p e r i e n c e S c a l e , which y i e l d s two mea s u r e s , was a d m i n i s t e r e d o n l y to t h e p a t i e n t g r o u p s . The above s e r i e s o f a n a l y s e s were f o l l o w e d by a s e t of c o r r e l a t i o n a l a n a l y s e s i n o r d e r to l o o k at the d a t a i n a d e s c r i p t i v e way. I n t e r r e l a t i o n s h i p s among the dependent measures were examined as w e l l as r e l a t i o n s h i p s between d i s a b i 1 i t y / p h y s i c a 1 i m p a i r m e n t measures and dependent measures, and the r e l a t i o n s h i p s among the t h r e e measures ot m e d i c a l i n c o n g r u i t y and the dependent m e a s u r e s . F i n a l l y , a p o s t hoc a n a l y s i s was c o n d u c t e d on t h r e e s e l e c t e d s u b g r o u p s of s u b j e c t s . P a i n p a t i e n t s were s e l e c t e d who had r e c e i v e d a f i n a l d i a g n o s i s from the Back P a i n C l i n i c as e x h i b i t i n g no a p p a r e n t o r g a n i c p a t h o l o g y or who were c o m p l a i n i n g o f d i s c o m f o r t t h a t was "out of p r o p o r t i o n " t o the d e t e c t a b l e p a t h o l o g y . E i g h t e e n s u c h p a t i e n t s ( 9 m a l e s ; 9 f e m a l e s ) were i d e n t i f i e d . In o r d e r t o form c o m p a r i s o n g r o u p s , e q u i v a l e n t numbers of normal c o n t r o l s u b j e c t s and p a i n p a t i e n t s who had r e c e i v e d c l e a r o r g a n i c d i a g n o s e s were r a n d o m l y - s e l e c t e d . The f i r s t s e r i e s of a n a l v s e s d e s c r i b e d above were c o m p l e t e d on t h i s new g r o u p i n g of the s u b j e c t p o o l . 63 R E S U L T S A n a l y s i s o i D e m o g r a p h i c V a r i a b l e s . C o n t i n u o u s d e m o g r a p h i c d a t a , age and s o c i o e c o n o m i c s t a t u s ( S E S ) , were a n a l y s e d u s i n g 3 X 2 ( g r o u p bv s e x ) ANOVAs. No s i g n i t i c a n t main e i i e c t s o r i n t e r a c t i o n s emerged on t h e s e v a r i a b l e s . T e s t i n g c o n d i t i o n s (room t e m p e r a t u r e and s k i n t e m p e r a t u r e ) were s i m i l a r l y a n a l y s e d and, a g a i n , no s y s t e m a t i c , d i t t e r e n c e s were r e v e a l e d . Means and s t a n d a r d d e v i a t i o n s t o r t h e d e m o g r a p h i c v a r i a b l e s a r e p r e s e n t e d i n T a b l e 7. T a b l e 7: Means and S t a n d a r d D e v i a t i o n s : C o n t i n u o u s D e m o g r a p h i c D a t a Group C o n t r o l C o n g r u e n t P a i n I n c o n g r u e n t P a i n V a r i a b l e M a l e s F e m a l e s . M a l e s F e m a l e s M a l e s F e m a l e s Age ( y e a r s ) x 41.4 39.4 38.1 43.7 39.6 39.8 sd 9.0 8.6 5.6 8.0 7.8 7.8 S E S 3 x 46.1 49.8 43.8 38.0 42.8 38.6 sd 14.2 11.9 14.4 17.0 14.4 13.8 _n = 15 per c e l l ( a ) h i g h e r s c o r e s r e f e r t o h i g h e r l e v e l s o f SES C a t e g o r i c a l d a t a ( m a r i t a l s t a t u s , e t h.n i c i t y , and employment s t a t u s ) were a n a l y s e d by g r o u p and by sex u s i n g C h i S q u a r e s t a t i s t i c s . A s i g n i f i c a n t g r o u p e f f e c t was f o u n d f o r m a r i t a l s t a t u s [ X " ( 2 ) = 11.97, p_< . 0 1 ] . E x a m i n a t i o n of t h e d a t a r e v e a l e d t h a t more s u b j e c t s i n the c o n t r o l g r o u p were s i n g l e t h a n i n t h e p a t i e n t g r o u p s . No s i g n i f i c a n t g r o u p e f f e c t s were 64 t o u n d t o r e t h n i c i t y and employment s t a t u s and no sex d i t t e r e n c e s on a n y o f : t h e above v a r i a b l e s emerged. The p e r c e n t a g e breakdown by g r o u p and sex f o r c a t e g o r i c a l d e m o g r a p h i c d a t a i s p r e s e n t e d i n T a b l e 8. T a b l e 8: P e r c e n t a g e Breakdown o f C a t e g o r i c a l D e m o g r a p h i c D a t a Group C o n t r o l C o n g r u e n t P a i n I n c o n g r u e n t P a i n V a r i a b l e M a l e s F e m a l e s M a l e s F e m a l e s M a l e s F e m a l e s Mar i t a 1 S t a t u s (S i n g 1 e ) 73 E t h n i c i t y ' ( C a u c a s i a n ) 100 67 87 27 80 33 100 40 100 27 93 Unemployed 20 33 33 33 40 n= 15 p e r c e l l A n a l y s i s o f P a t i e n t C h a r a c t e r i s t i c s . The p a t i e n t g r o u p s were a s s e s s e d w i t h r e s p e c t t o the p a r a m e t e r s o f t h e i r p a i n c o n d i t i o n s i C a t e g o r i c a l d a t a ( p r e s e n c e o r a b s e n c e of p r e v i o u s b a c k - r e l a t e d s u r g e r y ) were a n a l y s e d u s i n g C h i S q u a r e s t a t i s t i c s . No g r o u p or sex main e f f e c t s emerged from t h i s a n a l y s i s . I n t e r v a l d a t a ( d u r a t i o n of p a i n c o n d i t i o n , s t r e n g t h o f a n a l g e s i c m e d i c a t i o n , p e r c e n t a g e of o b j e c t i v e p h y s i c a l i m p a i r m e n t , and p e r c e n t a g e ot s u b j e c t i v e d i s a b i l i t y ) were a n a l y s e d u s i n g 2 X 2 ( p a i n g r o u p bv s e x ) ANOVAs. I t s h o u l d be n o t e d t h a t 54% of t h e d a t a f o r 65 t h e measure of p h y s i c a l i m p a i r m e n t was m i s s i n g b e c a u s e the p h y s i c i a n s d i d not c o m p l e t e the e x a m i n a t i o n s . T a b l e 9 l i s t s t h e means and s t a n d a r d d e v i a t i o n s o f t h e above v a r i a b l e s i n a d d i t i o n t o t h e r e s u l t s of t h e u n i v a r i a t e a n a l y s e s . No s i g n i f i c a n t main e f f e c t s o r i n t e r a c t i o n s were f o u n d f o r t h e d u r a t i o n of t h e p a i n c o n d i t i o n s , s t r e n g t h of m e d i c a t i o n consumed, and d e g r e e of o b j e c t i v e p h y s i c a l i m p a i r m e n t . However, s i g n i f i c a n t main e f f e c t s f o r b o t h g r o u p and sex were f o u n d f o r t h e measure o f s u b j e c t i v e d i s a b i l i t y . E x a m i n a t i o n of t h e d a t a r e v e a l e d t h a t i n c o m p a r i s o n to p a t i e n t s e x h i b i t i n g m e d i c a l l y c o n g r u e n t symptoms, p a t i e n t s w i t h i n c o n g r u e n t s y m p t o m a t o l o g y a l s o r e p o r t e d more f u n c t i o n a l d i s a b i l i t y . In a d d i t i o n , f e m a l e s were f o u n d t o r e p o r t more f u n c t i o n a l d i s a b i l i t y t h a n m a l e s . M e a s u r e s o f t h e l o s s of f u n c t i o n due t o a low back, p a i n c o n d i t i o n have a l s o been r e f e r r e d t o as m e a sures of s e v e r i t y ( W a d d e l i e t a l . , 1984; R e e s o r & C r a i g , 1 9 8 8 ) . The r e l a t i o n s h i p between the s e v e r i t y of t h e p a i n c o n d i t i o n , as m e a s u r e d by o b j e c t i v e and s u b j e c t i v e l o s s of f u n c t i o n , and i n c o n g r u e n t m e d i c a l s i g n s has been e v a l u a t e d i n p r e v i o u s i n v e s t i g a t i o n s ( W a d d e l i e t a l . , 1984; R e e s o r & C r a i g , 1 9 8 8). M o d e r a t e c o r r e l a t i o n s were r e p o r t e d among t h e s e m e a s u r e s w i t h t h e e x c e p t i o n o f t h a t between t h e P h y s i c a l I m p a irment Index and t h e N o n - o r g a n i c P h y s i c a l S i g n s ( R e e s o r & C r a i g , 1988). The r e l a t i o n s h i p s f o u n d i n t h e p r e s e n t s t u d y a r e p r e s e n t e d i n T a b l e 10. Of n o t e , the P h y s i c a l I mpairment Index i s not s i g n i f i c a n t l y c o r r e l a t e d w i t h t h e P a i n D r a w i n g or t h e Non- T a b i c 8. P a t i e n t C h a r a c t e r i s t i c : : Means and U n i v a r i a t e A n a l y s e s P a i n Croup S o u r c e C o n g r u e n t I n c o n g r u e n t C r o u p Sex C r o u p X Sex V a r i a b l e Males F e m a l e s M a l e s Females F C1 ,56) p F ( l , 5 6 ) £ F ( l , 5 6 ) p D u r a t i o n ( y e a r s ) 8.1 6.0 10.3 11.6 2.49 .120 .02 .880 . '.9 . 6 89 od 7.5 8.6 8.2 12.9 Med i c a t i on S t r c n g t h x. .47 .47 .80 .93 2.14 .149 .06 .808 .06 .808 sd .83 .92 1.26 1.16 0 s w c s t r v D i s a b i l i t y y. 22.5 31.3 34.6 45.9 13.51 .001 7.70 .007 .12 .728 sd 1 1 . 5 1 1 . 0 14.0 18.5 P h v s i c a l , I mpairment y. 13.6 14.5 15.0 16.2 .31 .583 .15 .70 .003 .955 sd 4.4 8.5 6.8 7.9 n 5 6 7 9 n_= 1 5 per c e l l Ca) H i g h e r s c o r e s r e f l e c t g r e a t e r s t r e n g t h s of a n a l g e s i c m e d i c a t i o n (b) Mote: u n e q u a l r\; F ( 1 , 2 3 ) 67 o r g a n i c P h y s i c a l S i g n s whereas the O s w e s t r v D i s a b i l i t v Q u e s t i o n n a i r e i s m o d e r a t e l y c o r r e l a t e d w i t h a l l t h r e e m e a s u r e s . T a b l e 10: C o r r e l a t i o n s Among M e a s u r e s ot P h y s i c a l L i m i t a t i o n and I n c o n g r u e n t S i g n s I n c o n g r u e n t P a i n M e a s u r e s M e a s u r e s ot P a i n N o n - o r g a n i c I n a p p r o p r i a t e P h y s i c a l L i m i t a t i o n D r a wing S i g n s Symptoms P h y s i c a l I m p airment Index (n=27) .29 .24 .36* O s w e s t r y D i s a b i l i t y Q u e s t i o n n a i r e (n=60) . 4 4 * * * .52*** .35** * p< . 05; ** p<.01 ; *** p<.00 1 68 A n a l y s i s o f Dependent M e a s u r e s . Group D i f f e r e n c e s : P a i n M e a s u r e s . Means and s t a n d a r d d e v i a t i o n s f o r a l l p a i n m e a s u r e s ( p a i n t h r e s h o l d , d' and b e t a c a l c u l a t e d r e l a t i v e t o t h e a v e r a g e p a i n t h r e s h o l d o f t h e n o r m a l c o n t r o l g r o u p , mean d' and mean b e t a c a l c u l a t e d f r o m t h e t h r e e c u t o f f l e v e l s , and s u b j e c t i v e p a i n r a t i n g ) a r e p r e s e n t e d i n T a b l e 11. T a b l e 11. Means and S t a n d a r d D e v i a t i o n s f o r P a i n M e a s u r e s Group C o n t r o l C o n g r u e n t P a i n I n c o n g r u e n t P a i n Va r i a b1e Ma 1 e s Fema1e s Ma 1 e s F e m a l e s Ma 1 e s Fema1e S T h r e s h o l d 2 ( m c a l / s e c / c m ) x 263.47 sd 24.77 260. 10 40.04 273.95 39.80 282.99 2 6.08 268.19 33.51 27 1.56 45.90 d • X sd 2 . 38 . 79 2.38 .83 1.99 . 6 1 2.62 .84 2.31 . 97 2.47 . 64 Mean d' X sd 2.52 . 62 2.51 . 66 2.21 . 5 4 2.85 .63 2.20 .87 2.41 . 4 7 B e t a X sd 30.53 49.35 15.91 39.17 22.68 44.02 42.66 5 2.14 34.27 49.65 35.60 5 2.92 Mean B e t a X sd 38.89 24.93 19.16 26.21 22.10 28.58 44.44 2 7.80 28.05 3 1.84 32.51 3 1.34 S u b j e c t i v e P a i n Ra t i ng X sd * . 07 . 90 . 22 . 64 -.41 . 8 1 . 20 . 9 5 - . 35 . 68 . 28 1.12 r e p o r t e d as z - s c o r e s ; r\= 1 5 per c e l l 69 P a i n p a t i e n t s were t i r s t compared as a g e n e r a l g r o u p t o th e c o n t r o l s u b j e c t s on t h e p a i n m e a s u r e s . B e c a u s e of u n e q u a l numbers i n e a c h g r o u p , t h e a s s u m p t i o n of h o m o g e n e i t y of v a r i a n c e was a s s e s s e d u s i n g t h e Box M t e s t w h i c h r e v e a l e d t h a t t h e v a r i a n c e s f o r t h e p a i n m e a s u r e s d i d n o t d i f f e r s i g n i f i c a n t l y between t h e g r o u p s . T h r e s h o l d was t h e n a n a l y s e d i n a 2 X 2 ( g r o u p by s e x ) ANOVA w h i c h r e v e a l e d no s i g n i f i c a n t main e f f e c t s o r i n t e r a c t i o n s ( s e e T a b l e 1 3 ) . The SDT i n d i c e s c a l c u l a t e d u s i n g t h e mean p a i n t h r e s h o l d o f n o r m a l c o n t r o l s u b j e c t s as a c u t o f f were f i r s t a n a l y z e d w i t h t h e s u b j e c t i v e p a i n r a t i n g i n a 2 X 2 MANOVA w h i c h y i e l d e d no s i g n i f i c a n t f i n d i n g s ( s e e T a b l e 1 2 ) . G i v e n t h e n e g a t i v e r e s u l t , t h e mean d' and mean b e t a m e a s u r e s were u s e d i n p l a c e i n o r d e r t o c o n t r o l f o r l o s t power b e c a u s e of t h e h i g h v a r i a b i l i t y i n t h e d' and b e t a m e a s u r e s . The r e s u l t s o f t h i s a n a l y s i s a l s o a p p e a r i n T a b l e 12. As can be s e e n , t h i s MANOVA r e v e a l e d no s i g n i f i c a n t g r o u p o r sex e f f e c t s ; however, a s i g n i f i c a n t g r o u p by sex i n t e r a c t i o n was f o u n d when t h e more s t a b l e a v e r a g e d m e a s u r e s o f d' and b e t a were u s e d . 70 Tab 1e 12. MANOVA Summary T a b l e l o r P a i n M e a s u r e s W i t h P a i n P a t i e n t s P o o l e d S o u r c e W i l k s Lambda F j ( S = l , M = 1 / 2 , N = 4 1 ) MANOVA U s i n g d' and B e t a M e a s u r e s Group .97 .79 .504 Sex .94 1.65 .183 Group X Sex .96 1.10 .358 MANOVA U s i n g Mean d' and B e t a M e a s u r e s Group .98 .60 .614 Sex .93 2.09 .108 Group X Sex .90 3.10 .031 G i v e n t h e s i g n i f i c a n t f i n d i n g on t h e MANOVA when t h e a v e r a g e d d' and b e t a m e a s u r e s a r e u s e d , f o l l o w - u p u n i v a r i a t e a n a l y s e s were c o n d u c t e d , as p r e s e n t e d i n T a b l e 13. The a n a l y s e s r e v e a l e d t h a t t h e g r o u p by sex i n t e r a c t i o n i s r e p r e s e n t e d by t h e mean c r i t e r i o n measure ( b e t a ) . E x a m i n a t i o n of t h e means i n d i c a t e d t h a t w i t h i n t h e c o n t r o l g r o u p , men s e t h i g h e r c r i t e r i a t o r e p o r t s e n s a t i o n s as p a i n f u l t h a n women. However, w i t h i n t h e p a t i e n t g r o u p , men s e t l o w e r c r i t e r i a t o r e p o r t p a i n f u l s e n s a t i o n s t h a n women. 71 T a b l e 13. U n i v a r i a t e A n a l v s e s : P a i n M e a s u r e s W i t h P a i n P a t i e n t s P o o l e d . S o u r c e Group Sex Group X Sex V a r i a b l e F ( 1 , 8 6 ) £ F( 1 ,86) p_ F( 1 ,86) £ Mean d* .41 .522 2.09 .152 2.31 . 132 Mean B e t a .19 .667 .25 .621 6.76 .011 S u b j e c t i v e P a i n R a t i n g 3 1.20 .275 4.03 .048 1.52 .222 T h r e s h o l d 6 2.42 .124 2.42 .124 .36 .5 50 (a ) C a l c u l a t e d on z - s c o r e s (b) Not i n c l u d e d as a p a r t of t h e MANOVA The a b s e n c e o± a g r o u P e f f e c t f o r p a i n m e a s u r e s was h y p o t h e s i z e d t o r e f l e c t t h e h e t e r o g e n e i t y o b s e r v e d i n the p a i n p a t i e n t s ' manner o f p a i n p r e s e n t a t i o n . T h e r e f o r e , pa i n p a t i e n t s were d i v i d e d i n t o two e q u a l g r o u p s on t h e ba s i s o i t h e p r e s e n c e o r a b s e n c e of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms and the above ana 1 y s e s were r e p e a t e d . T h r e s h o l d f o r f a i n t p a i n was f i r s t a n a l y s ed i n a 3 X 2 ( g r o u p by se x) ANOVA. A g a i n , no main e f f e c t s or i n t e r a c t i o n s were e v i d e n t f rom t h e s e a n a l y s e s w h i c h a r e p r e s e n t e d i n T a b l e 15. S i g n a l Det e c t i on i n d i c e s ( d 1 and b e t a c a l c u 1 a t e d r e l a t i v e t o t h e mean p a i n t h r e s h o l d of n o r m a l c o n t r o 1 s u b j e c t s ) were a g a i n a n a l y s e d w i t h t h e s u b j e c t i v e p a i n r a t i n g u s i n g a 3 X 2 MANOVA ( s e e T a b l e 1 4 ) . As can be s e e n , t h i s a n a l y s i s y i e l d e d no s i g n i f i c a n t g r o u p e f f e c t s or g r o u p by s ex i n t e r a c t i o n s . However, a 72 b o r d e r l i n e s i g n i t i c a n t f i n d i n g was e v i d e n t t o r sex d i f f e r e n c e s . A g a i n , i n o r d e r t o c o n t r o l t o r l o s t power due to t h e h i g h v a r i a b i l i t y i n d' and b e t a , t h e a n a l y s i s was r e p e a t e d u s i n g t h e a v e r a g e d d' and b e t a m e a s u r e s . T h e s e r e s u l t s a l s o a p p e a r i n T a b l e 14 w h i c h a g a i n r e v e a l e d no s i g n i f i c a n t o v e r a l l g r o u p d i f f e r e n c e s on p a i n m e a s u r e s . However, the main e f f e c t f o r sex was s t r o n g e r and s i g n i f i c a n t i n t h i s a n a l y s i s and, a l t h o u g h n o t s t a t i s t i c a l l y s i g n i f i c a n t a c c o r d i n g t o c o n v e n t i o n a l g u i d e l i n e s , t h e r e i s a s u g g e s t i o n o f a t r e n d i n th e d a t a w i t h r e s p e c t t o an i n t e r a c t i o n e f f e c t . B e c a u s e t h e p o o l e d d' and b e t a m e a s u r e s a r e more s t a b l e and, t h e r e f o r e , have g r e a t e r power, t h e y were be us e d i n s u b s e q u e n t a n a l y s e s . T a b l e 14. MANOVA Summary T a b l e t o r P a i n M e a s u r e s W i t h P a i n P a t i e n t s S e p a r a t e d i n t o M e d i c a l l y C o n g r u e n t and I n c o n g r u e n t G r o u p s S o u r c e W i I k s Lambda MANOVA U s i n g d' and B e t a M e a s u r e s Group .97 .42 .865 Sex .91 2.63 .056 G r o u p X S e x .95 .75 .611 MANOVA U s i n g Mean d* and B e t a M e a s u r e s Group .95 .66 .679 Sex .90 3.13 .030 G r o u p X S e x .89 1.83 .0 97 U n i v a r i a t e f o l l o w - u p t e s t s were examined g i v e n the s i g n i f i c a n t sex e f f e c t i n t h e MANOVA u s i n g t h e a v e r a g e d SDT i n d i c e s . The r e s u l t s of t h e s e a n a l y s e s a r e p r e s e n t e d i n T a b l e 15 and i n d i c a t e a sex e f f e c t f o r t h e me a s u r e s of d' ( s e n s o r y s e n s i t i v i t y ) and S u b j e c t i v e P a i n R a t i n g . I n s p e c t i o n of t h e 73 means ot t h e s e v a r i a b l e s showed t h a t women were b e t t e r a b l e t o d i s t i n g u i s h t h e p a i n s i g n a l f r o m t h e h e a t and a l s o r a t e d t h e s t i m u l i as more i n t e n s e and d i s t r e s s i n g t h a n t h e men. As m e n t i o n e d a b o v e , i t i s r e c o g n i z e d t h a t a s i g n i f i c a n t o v e r a l l g r o u p by sex i n t e r a c t i o n was n o t f o u n d ; however, t h e t r e n d f o u n d i n t h e a n a l y s i s i s q u a l i t a t i v e l y s i m i l a r t o t h a t w h i c h was f o u n d t o be s i g n i f i c a n t when t h e p a i n p a t i e n t s were p o o l e d . T a b l e 15. U n i v a r i a t e A n a l v s e s : P a i n M e a s u r e s S o u r c e Group Sex Group X Sex V a r i a b l e F ( 2 , 8 4 ) £ F ( 1 , 8 4 ) £ F( 2 , 84 ) £ Mean d' 1.14 .324 4.36 .040 1.98 .144 Mean B e t a .17 .840 .15 .696 4.10 .0 20 Sub i e c t i v e P a i n R a t i n g .63 .533 6.44 .013 . 74 .479 T h r e s h o l d 6 1.62 .203 .16 .69 1 . 22 . 799 (a ) C a l c u l a t e d on z - s c o r e s ( b ) Not i n c l u d e d as a p a r t o f the MANOVA R e l a t i o n s h i p s Among t h e P a i n M e a s u r e s . I n t e r c o r r e l a t i o n s among t h e s e m e a s u r e s were e v a l u a t e d w i t h P e a r s o n c o r r e l a t i o n c o e f f i c i e n t s w h i c h a r e p r e s e n t e d i n T a b l e 16. In t h i s t a b l e , t h e s u b j e c t i v e p a i n r a t i n g f r o m the G r a c e l y R a t i n g S c a l e i s p r e s e n t e d i n i t s two component s : s e n s o r y i n t e n s i t y and u n p l e a s a n t n e s s o r a f f e c t i v e d i s t r e s s • Of n o t e , a m o d e r a t e p o s i t i v e c o r r e l a t i o n was fo u n d between the 74 p a i n t h r e s h o l d and t h e o a i n r e p o r t c r i t e r i o n but no s i g n i f i c a n t a s s o c i a t i o n was f o u n d between p a i n t h r e s h o l d and d i s c r i m i n a b i 1 i t y . The r e l a t i o n s h i p between t h e c r i t e r i o n and p a i n t h r e s h o l d s u g g e s t s t h a t p a i n t h r e s h o l d i s p r i m a r i l y r e p r e s e n t e d by a r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s as p a i n f u l . A l s o f o u n d was a m o d e r a t e c o r r e l a t i o n between d' ( s e n s o r y d i s c r i m i n a t i o n ) and b e t a ( p a i n r e p o r t c r i t e r i o n ) . T h i s c o r r e l a t i o n i s i n t e r p r e t t e d t o mean t h a t t h o s e s u b j e c t s who s e t a h i g h e r c r i t e r i o n t o r e p o r t p a i n were a l s o more c o n s i s t e n t i n t h e i r j u d g e m e n t s . T h a t i s , t h o s e who s e t a h i g h c r i t e r i o n t o r e p o r t p a i n had f e w e r f a l s e a l a r m s r e l a t i v e to t h e h i t s i n d e t e c t i n g p a i n . A low but s i g n i f i c a n t n e g a t i v e c o r r e l a t i o n was f o u n d between the r a t i n g of s e n s o r y i n t e n s i t y and p a i n t h r e s h o l d - s u g g e s t i n g t h a t t h o s e w i t h low p a i n t h r e s h o l d s a l s o t e n d e d t o r e p o r t g r e a t e r s u b j e c t i v e i n t e n s i t y o f p a i n . F i n a l l y , a low p o s i t i v e r e l a t i o n s h i p was f o u n d between d' ( s e n s o r y d i s c r i m i n a t i o n ) and s e l f - r e p o r t of a f f e c t i v e d i s t r e s s o r u n p l e a s a n t n e s s c a u s e d by p a i n . T h i s w o u l d s u g g e s t a s l i g h t t e n d e n c y f o r t h o s e who a r e more s e n s i t i v e t o p a i n f u l s t i m u l i t o a l s o be more d i s t r e s s e d by the p a i n . 75 T a b l e l b . C o r r e l a t i o n M a t r i x : P a i n M e a s u r e s Mean Mean S e n s o r y A t t e c t i v e d 1 B e t a T h r e s h o l d I n t e n s i t y D i s t r e s s Mean d' Mean B e t a T h r e s h o l d S e n s o r v I n t e n s i t y A f f e c t i v e D i s t r e s s n=90; *<.05; ***< . 001 Group D i f f e r e n c e s : C o g n i t i v e M e a s u r e s . The means and s t a n d a r d d e v i a t i o n s of t h e f i v e m e a s u r e s o b t a i n e d f r o m t h e C o o i n g S t r a t e g y Q u e s t i o n n a i r e a r e p r e s e n t e d i n T a b l e 17. The f i v e m e a s u r e s a r e c o g n i t i v e c o p i n g p r o c e s s e s ( i . e . , a c t i v e c o p i n g s t r a t e g i e s s u c h as r e i n t e r p r e t a t i o n o f the p a i n and c o p i n g s e 1 f - s t a t e m e n t s ) , s t r a t e g i e s w i t h s p e c i f i c c o g n i t i v e c o n t e n t ( i . e . , p a s s i v e c o p i n g s t r a t e g i e s s u c h as p r a y i n g , h o p i n g , and d i v e r t i n g a t t e n t i o n ) , s e 1 f - e f f i c a c y to c o n t r o l t h e p a i n , b e h a v i o u r a l c o p i n g s t r a t e g i e s , and c a t a s t r o p h i z i n g c o g n i t i o n s . H i g h e r s c o r e s r e f l e c t g r e a t e r s e l f - r e p o r t e d use o f e a c h component. 50*** 12 .52*** 16 -.14 -.20* 18* -.04 -.02 .58*** 76 T a b l e 17. Means and S t a n d a r d D e v i a t i o n s f o r C o g n i t i v e Me a s u r e s Group C o n g r u e n t P a i n I n c o n g r u e n t P a i n V a r i a b l e Males F e m a l e s Males F e m a l e s P r o c e s s e s x 3 9. 73 4 5 .07 39.67 47.33 sd 12. 34 14 .80 15.30 16.95 C o n t e n t x 17. 00 23 .07 21.47 29.87 sd 10 . 7 1 12 .09 10.94 14.29 E f f i c a c y x 4 . 93 6 .53 4.80 5 . 40 sd 2 . 25 1 .36 2.60 2.06 B e h a v i o u r a l C o p i n g x 12. 40 1 7 .93 13.73 16.33 sd 6 . 8 1 6 .69 5.40 5.27 C a t a s t r o p h i z i n g x 7 . 47 7 .13 8.40 12.07 sd 5 . 76 7 .62 5.65 9.11 n=15 per c e l l These v a r i a b l e s were e n t e r e d i n t o a 2 X 2 ( p a i n group by sex ) MANOVA ( s e e T a b l e 1 8 ) . No s i g n i f i c a n t ma i n e f f e c t s or i n t e r a c t i o n s were r e v e a l e d t h r o u g h t h e s e a n a l y s e s However, t h e r e i s a t r e n d i n the d a t a t o s u g g e s t some sex d i f f e r enc e s. T a b l e , 1 8 . MANOVA Summary T a b l e t o r C o g n i t i v e Me a s u r e s' S o u r c e W i l k s Lambda F £ Group .88 1 . 40 .241 Sex / .83 2.09 .08 1 G r o u p X S e x . 95 . 52 .761 view 11 to was d e c i d e d t o l o o k at the u n i v a r i a t e a n a l y s e s e x a m i n i n g the v a r i a b l e s f o r the a p p a r e n t t r e n d w i t h a 77 d i f f e r e n t i a t i n g t h e s e x e s - R e s u l t s o f t h e s e a n a l y s e s a r e p r e s e n t e d i n T a b l e 19. T a b l e 19. U n i v a r i a t e A n a l y s e s : C o g n i t i v e M e a s u r e s S o u r c e Group Sex Group X Sex Var i a b1e F( 1 , 56) £ F ( 1 , 5 6 ) F( 1 , 56) £ C o n t e n t 3.26 .077 5.37 .024 . 1 4 .710 P r o c e s s .08 .777 2.84 .098 .09 .763 E f f i c a c y 1.34 .251 4.05 .049 . 84 .364 C a t a s t r o - p h i z i n g 2.50 .119 .81 .373 1.16 .285 B e h a v i o u r . 0 1 .933 6.70 .012 . 87 .355 The a p p a r e n t sex d i f f e r e n c e a p p e a r s on t h e f o l l o w i n g v a r i a b l e s : c o g n i t i v e c o n t e n t , e f f i c a c y t o manage t h e p a i n , and b e h a v i o u r a l c o p i n g s t r a t e g i e s . More women t h a n men a d m i t t e d t o u s i n g c o p i n g s t r a t e g i e s ( s u c h as d i s t r a c t i n g t h e m s e l v e s by e n g a g i n g i n o t h e r b e h a v i o u r a l or c o g n i t i v e a c t i v i t i e s ) and t o be more s e l f - e f f i c a c i o u s t o manage t h e i r p a i n . B e c a u s e t h e s e d i f f e r e n c e s were not f o u n d to be s t a t i s t i c a l l y s i g n i f i c a n t on t h e m u l t i v a r i a t e t e s t s , t h e y w i l l o n l y be d i s c u s s e d i n a q u a l i t a t i v e way. 78 R e l a t i o n s h i p s Among t h e C o g n i t i v e M e a s u r e s . I n t e r r a t i o n s h i p s among t h e c o g n i t i v e m e a s u r e s were a s s e s s e d u s i n g P e a r s o n C o r r e l a t i o n c o e f f i c i e n t s w h i c h a r e p r e s e n t e d i n t h e f o r m o f a m a t r i x i n T a b l e 20. I n c l u d e d i n t h i s m a t r i x i s an o v e r a l l c o m p o s i t e s c o r e c a l l e d ' c o p i n g ' w h i c h r e f l e c t s t h e sum of a l l t h e s u b s c a l e s o f t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e . T a b l e 20. C o r r e l a t i o n M a t r i x : C o g n i t i v e M e a s u r e s C a t a s t r o - C o n t e n t P r o c e s s E f f i c a c y p h i z i n g B e h a v i o u r C o p i n g C o n t e n t P r o c e s s .61*** " E f f i c a c y .18 .12 Cat a s t r o - p h i z i n g .26* .08 -.31** B e h a v i o u r .55*** .36** .38*** -.01 C o p i n g .83*** .86*** .31** .04 .89*** n=60; * £ < . 0 5 ; * * £ < . 0 1 ; * * * £ < . 0 0 1 H i g h p o s i t i v e c o r r e l a t i o n s were f o u n d between t h e o v e r a l l ' c o p i n g ' c o m p o s i t e measure and t h e c o p i n g s t r a t e g i e s r e p r e s e n t i n g s p e c i f i c c o g n i t i v e c o n t e n t and p r o c e s s e s i n a d d i t i o n t o b e h a v i o u r a l s t r a t e g i e s . T h i s would s u g g e s t t h a t t h e more w e i g h t e d s u b s c a l e s on t h e q u e s t i o n n a i r e a r e t h o s e a c t u a l l y r e f l e c t i n g c o p i n g s t r a t e g i e s f o r p a i n . E f f i c a c y r e f l e c t s how w e l l the c o p i n g s t r a t e g i e s a r e p e r c e i v e d to work and c a t a s t r o p h i z i n g , i n e f f e c t , r e f l e c t s ' n o n - c o p i n g ' . 79 M o d e r a t e t o h i g h p o s i t i v e c o r r e l a t i o n s were t o u n d among the c o p i n g s u b s c a l e s i n c l u d i n g e t t i c a c y . A m o d e r a t e t o low n e g a t i v e c o r r e l a t i o n was t o u n d between c a t a s t r o p h i z i n g and e t t i c a c y w h i c h s u g g e s t s t h a t t h e more a p e r s o n c a t a s t r o p h i z e s a b o u t h i s / h e r p a i n , t h e l e s s e f f i c a c i o u s h e / s h e f e e l s i n b e i n g a b l e t o manage t h e p a i n . Group D i f f e r e n c e s : A f f e c t i v e M e a s u r e s . The means and s t a n d a r d d e v i a t i o n s f o r the t h r e e m e a s u r e s of a f f e c t , t h e T r a i t S c a l e of t h e S t a t e - T r a i t A n x i e t y I n v e n t o r y and t h e two s u b s c a l e s of t h e P a i n E x p e r i e n c e S c a l e (Worry and E m o t i o n a l i t y ) a r e p r e s e n t e d i n T a b l e 21. The T r a i t A n x i e t y measure ( S T A I ) was a n a l y s e d i n a 3 X 2 ( g r o u p by s e x ) ANOVA. No s i g n i f i c a n t main e f f e c t s or i n t e r a c t i o n s were r e v e a l e d i n t h e s e a n a l y s e s . B e c a u s e t h e P a i n E x p e r i e n c e S c a l e e v a l u a t e s d i s t r e s s s p e c i f i c t o c h r o n i c p a i n , i t was n o t a d m i n i s t e r e d t o t h e c o n t r o l g r o u p . Two-way ANOVAs were c o n d u c t e d on e a c h m e a s u r e . No s i g n i f i c a n t main e f f e c t s or i n t e r a c t i o n s emerged on any of t h e v a r i a b l e s . 80 T a b l e 2 1. Means and S t a n d a r d D e v i a t i o n s : A t t e c t i v e M e a s u r e s Group C o n t r o l V a r i a b l e M a l e s F e m a l e s C o n g r u e n t P a i n I n c o n g r u e n t P a i n Ma1e s Fema1e s M a l e s F e m a l e s T r a i t Anx i e t y x 36.07 sd 7.04 Wo r r y x sd Emo t i o n a 1 i t y x sd 33.47 6.52 34.80 9.06 2 .37 1.13 03 34 35 9 3 1 2 1 47 2 0 0 1 34 78 5 9 35.73 8.66 3 1 28 50 2.49 1 . 40 3 6.53 6.66 3.10 1.38 3.03 1 . 60 N o t e : H i g h e r s c o r e s r e f l e c t h i g h e r l e v e l s of a f f e c t , n = 15 p e r c e l l R e l a t i o n s h i p s Among t h e A f f e c t i v e M e a s u r e s . I n t e r r a t i o n s h i p s were a g a i n a s s e s s e d u s i n g P e a r s o n c o r r e l a t i o n c o e f f i c i e n t s w h i c h a p p e a r as a c o r r e l a t i o n m a t r i x i n T a b l e 22. H i g h p o s i t i v e c o r r e l a t i o n s were f o u n d among a l l t h r e e m e a s u r e s . T a b l e 22. C o r r e l a t i o n M a t r i x : A f f e c t i v e M e a s u r e s STAI (n=90) T r a i t Anx i e t v P a i n E x p e r i e n c e S c a l e (ri=60) Worrv E m o t i o n a 1 i t v T r a i t A n x i e t y Wo r r y E m o t i o n a l i t v 66*** 7 5 * * * 76*** [p_< .00 1 81 A d d i t i o n a l C o r r e l a t i o n a l A n a l y s e s . R e l a t i o n s h i p s Among t h e Dependent M e a s u r e s . I t was of i n t e r e s t t o examine t h e r e l a t i o n s h i p s among the d i f f e r e n t d e p e n d e n t m e a s u r e s as w e l l as between t h e d e p e n d e n t m e a s u r e s and t h e m e a s u r e s of s e v e r i t y and symptom p r e s e n t a t i o n . A l t h o u g h t h i s k i n d of a n a l y s i s becomes more l i b e r a l w i t h number of c o r r e l a t i o n s c a l c u l a t e d , t h e g o a l was to i d e n t i f y p o s s i b l e t r e n d s i n t h e d a t a f o r h e u r i s t i c p u r p o s e s . T a b l e 23 p r e s e n t s t h e P e a r s o n c o r r e l a t i o n c o e f f i c i e n t s between t h e p a i n m e a s u r e s and the m e a s u r e s of c o g n i t i v e c o p i n g and a f f e c t . A g a i n , t h e s u b j e c t i v e p a i n r a t i n g s , d e r i v e d f r o m the G r a c e l y R a t i n g Sca l e s " , a r e p r e s e n t e d i n t h e i r component s c a l e s : S e n s o r y I n t e n s i t y and A f f e c t i v e D i s t r e s s . Of n o t e , i s t h e a b s e n c e of s i g n i f i c a n t c o r r e l a t i o n s among t h e s e m e a s u r e s w i t h t h e e x c e p t i o n of a s m a l l p o s i t i v e r e l a t i o n s h i p between p a i n t h r e s h o l d and c o g n i t i v e c o n t e n t s u g g e s t i n g t h a t t h o s e w i t h h i g h e r p a i n t h r e s h o l d s a l s o r e p o r t u s i n g c o p i n g s t r a t e g i e s w i t h s p e c i f i c c o g n i t i v e c o n t e n t . In a d d i t i o n , a low p o s i t i v e c o r r e l a t i o n between c a t a s t r o p h i z i n g and r e p o r t e d s e n s o r y i n t e n s i t y of t h e p a i n s t i m u l i was f o u n d s u g g e s t i n g a t e n d e n c y f o r t h o s e who c a t a s t r o p h i z e a b o u t t h e i r p a i n c o n d i t i o n t o a l s o r e p o r t a h i g h e r s e n s o r y i n t e n s i t y of e x t e r n a l p a i n s t i m u l i . Among t h e a f f e c t i v e m e a s u r e s , a g a i n t h e r e i s a n o t a b l e a b s e n c e of r e l a t i o n s h i p w i t h t h e p a i n m e a s u r e s w i t h the e x c e p t i o n of low p o s i t i v e c o r r e l a t i o n s between t h e s e l f - r e p o r t 82 of s e n s o r y i n t e n s i t y and the s u b s c a l e s of the P a i n E x p e r i e n c e S c a l e . These r e l a t i o n s h i p s s u g g e s t a s l i g h t t e n d e n c y f o r t h o s e who a r e more w o r r i e d and e m o t i o n a l about t h e i r p a i n c o n d i t i o n t o a l s o r e p o r t h i g h e r s e n s o r y i n t e n s i t y r a t i n g s of e x t e r n a l p a i n s t i m u l i . Tab 1 e 2 3. R e l a t i o n s h i p s Between P a i n Measures and C o g n i t i v e and A f f e c t i v e M e a s u r e s P a i n Me a s u r e s T h r e s h o l d Mean d ' Mean Beta S e n s o r y I n t e n s i t y Af t e c t i v e D i s t r e s s Cogn i t i ve Measures C o n t e n t - . 22* .02 - . 01 .17 - . 08 P r o c e s s e s -.14 -.10 - . 10 -.01 -.12 E f f i c a c y -.11 - . 02 -.18 -.18 -.17 C a t a s t r o - p h i z i n g -.12 .15 .02 .33** .04 Behav i o u r a 1 C o p i n g - . 04 . 00 . 04 - . 09 -.15 O v e r a l l C o p i n g -.14 - . 02 .02 -.01 -.12 A f f e c t i v e M e a s ures T r a i t A n x i e t y - . l>4 - . 01 - . 03 . 1 3 . 08 Wor r y - . 04 . 1 2 .00 . 28** . 10 Emot i o n - a l i t y .06 .14 .0 5, .31** . 18 n=60; *£<.05; **£<.01 R e l a t i o n s h i p s between t h e c o g n i t i v e and a f f e c t i v e v a r i a b l e s , as e v a l u a t e d w i t h P e a r s o n c o r r e l a t i o n c o e f f i c i e n t s , 83 r e v e a l e d m o d e r a t e t o h i g h c o r r e l a t i o n s between c a t a s t r o p h i z i n g and a l l t h r e e a t t e c t i v e m e a s u r e s . C a t a s t r o p h i z i n g c o r r e l a t e d a t .68 (p_<.001) w i t h b o t h Worry and E m o t i o n a l i t y and a t .50 ( j 3<.001) w i t h t h e T r a i t S c a l e ot t h e S T A I . No s i g n i t i c a n t r e l a t i o n s h i p s were f o u n d t o r any ot t h e o t h e r c o g n i t i v e v a r i a b l e s and t h e a t t e c t i v e m e a s u r e s . T h i s s u p p o r t s a c u r r e n t v i e w ot t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e t h a t the C a t a s t r o p h i z i n g s c a l e r e p r e s e n t s e m o t i o n a l t a c t o r s and n o t a c o g n i t i v e c o n s t r u c t a s s u c h (Lawson e t a l . , 1 9 9 0 ) . R e l a t i o n s h i p B e t w e e n D e p e n d e n t M e a s u r e s a n d M e a s u r e s o t S e v e r i t y a n d S y m p t o m P r e s e n t a t i o n . The r e l a t i o n s h i p s between m e a s u r e s ot s e v e r i t y ( P h y s i c a l I m p a i r m e n t Index and t h e O s w e s t r y D i s a b i l i t y Q u e s t i o n n a i r e ) and symptom p r e s e n t a t i o n and t h e d e p e n d e n t m e a s u r e s were e v a l u a t e d u s i n g P e a r s o n C o r r e l a t i o n c o e t t i c i e n t s w h i c h a p p e a r i n T a b l e 24. The m e a s u r e s ot s e v e r i t y were not a t a l l a s s o c i a t e d w i t h t h e p a i n v a r i a b l e s . T h i s was a l s o t r u e t o r t h e m e a s u r e s ot symptom p r e s e n t a t i o n w i t h the e x c e p t i o n ot a s m a l l n e g a t i v e c o r r e l a t i o n between p a i n t h r e s h o l d and Non- o r g a n i c P h y s i c a l S i g n s . T h a t i s . t h e l o w e r th e p a i n t h r e s h o l d , t h e more n o n - o r g a n i c p h y s i c a l s i g n s were d i s p l a y e d . Low t o m o d e r a t e p o s i t i v e c o r r e l a t i o n s were t o u n d between t h e c o p i n g t a c t o r r e f l e c t i n g s p e c i t i c c o g n i t i v e c o n t e n t and b o t h m e a s u r e s ot s e v e r i t y and symptom p r e s e n t a t i o n . T h i s t a c t o r c o n s i s t s ot t h e s u b s c a l e s a s s e s s i n g p r a y i n g / h o p i n g and d i v e r t i n g a t t e n t i o n t o o t h e r m e n t a l a c t i v i t i e s . Ot i n t e r e s t i s a c o n s i s t e n t p o s i t i v e a s s o c i a t i o n between t h e P a i n D r a w i n g 84 as s c o r e d by the R a n s f o r d et a l . (1976) s c o r i n g method and m e a s u r e s o f a f f e c t i n c l u d i n g t h e c a t a s t r o p h i z i n g s c a l e o f t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e . T h i s would seem t o i n d i c a t e t h a t t h i s method of s c o r i n g t h e p a i n d r a w i n g r e f l e c t s a s t r o n g a f f e c t i v e component o f c h r o n i c p a i n c o n d i t i o n s . The o t h e r two m e a s u r e s o f symptom p r e s e n t a t i o n ( N o n o r g a n i c P h y s i c a l S i g n s and I n a p p r o p r i a t e Symptoms) were u n r e l a t e d t o m e a s u r e s ot a f f e c t . F i n a l l y , i t i s i n t e r e s t i n g t o n o t e a low t o m o d e r a t e l e v e l of p o s i t i v e a s s o c i a t i o n between o b j e c t i v e p h y s i c a l i m p a i r m e n t and w o r r y s p e c i f i c t o t h e p a i n c o n d i t i o n i t s e l f but an a p p a r e n t a b s e n c e of a s s o c i a t i o n t o s u b j e c t i v e d i s a b i l i t y . E m o t i o n a l i t y r e g a r d i n g t h e p a i n c o n d i t i o n was, however, p o s i t i v e l y a s s o c i a t e d w i t h s u b j e c t i v e d i s a b i l i t y but not p h y s i c a l i m p a i r m e n t . 85 T a b l e 2 4. C o r r e l a t i o n s Among M e a s u r e s ot S e v e r i t y and SymDtom P r e s e n t a t i o n and Dependent M e a s u r e s M e a s u r e s ot S e v e r i t v M e a s u r e s ot SvmDtom P r e s e n t a t i o n D ependent I m p a i r - D i s a b i l - P a i n N o n - o r g a n i c I n a p p r o p r i a t e V a r i a b l e m e n t 3 i t y Draw S i g n s Symptoms P a i n M e a s u r e s T h r e s h o l d -.12 .13 -.04 -.29* -.16 M e a n d ' -.14 .14 -.08 -.05 -.0 7 Mean B e t a -.20 .19 -.07 -.09 -.12 S e n s o r v I n t e n s i t y .15 .20 .12 .22 .18 Af-f e c t i v e D i s t r e s s .30 .14 .14 .12 .08 C o g n i t i v e M e a s u r e s C o n t e n t .33* . 4 4 * * * .30* .36** .30* P r o c e s s e s .03 .22* .29* .28* .01 E t t i c a c y .22 -.09 -.07 -.06 -.24* C a t a s t r o - p h i z i n g .13 .25* .33** .27* .24* B e h a v i o u r .24 .14 .12 .21 -.05 C o p i n g .17 .29* .19 .30* .04 A f f e c t i v e M e a s u r e s T r a i t A n x i e t y .15 .09 .32** .00 .03 Worry .3 5* .18 .31** .09 .17 E m o t i o n a l i t y .13 .30** .30** .11 .11 n = 6 0 ; ( a ) n = 2 7 * £ < . 0 5 ; * * £ < . 0 1 ; * * * £ < . 0 0 1 86 P o s t Hoc A n a l y s e s . The c1 a s s i t i c a t i o n scheme u s e d i n t h i s s t u d y was b a s e d on t h e ' i n c 1 u s i o n a r y 1 c r i t e r i a u s e d i n a p r e v i o u s i n v e s t i g a t i o n w h i c h s o u g h t t o i d e n t i t y p a i n p a t i e n t s t o r whom p s y c h o l o g i c a l t a c t o r s p l a y e d a l a r g e r r o l e i n t h e i r p a i n c o n d i t i o n ( R e e s o r & C r a i g , 1988) . T h i s s y s t e m was s u c c e s s f u l i n d i s t i n g u i s h i n g two g r o u p s ot p a i n p a t i e n t s d e s i g n a t e d as t h o s e w i t h and w i t h o u t m e d i c a l l y i n c o n g r u e n t symptoms. The two g r o u p s i n t h e e a r l i e r s t u d y were d i f f e r e n t i a t e d on p s y c h o l o g i c a l t a c t o r s s u c h as c a t a s t r o p h i c c o g n i t i o n s r e g a r d i n g p a i n , low s e l t - e t t i c a c y t o c o n t r o l p a i n , and h i g h e r s u b j e c t i v e r a t i n g s ot p a i n i n t e n s i t y . B e c a u s e g r o u p d i t t e r e n c e s were n o t f o u n d when the p a i n p a t i e n t s were d i f f e r e n t i a t e d on t h e b a s i s ot t h e i r symptom p r e s e n t a t i o n i n t h e p r e s e n t s t u d y , p a t i e n t s i n t h i s sample were r e c l a s s i f i e d on t h e b a s i s ot ' e x c l u s i o n a r y ' c r i t e r i a . T h a t i s , p a t i e n t s d i a g n o s e d w i t h no a p p a r e n t o r g a n i c p a t h o l o g y o r whose c o m p l a i n t s ot p h y s i c a l d i s c o m f o r t were " o u t ot p r o p o r t i o n " t o d e t e c t a b l e p a t h o l o g y were s e l e c t e d ( i . e . , ' f u n c t i o n a l ' p a t i e n t s ) . N i n e m a l e s and n i n e f e m a l e s r e c e i v e d s u c h d i a g n o s e s w h i c h were a r r i v e d a t t h r o u g h team c o n f e r e n c e s i n v o l v i n g an o r t h o p a e d i c s u r g e o n , g e n e r a l p r a c t i c e p h y s i c i a n , p h y s i o t h e r a p i s t , and p s y c h o l o g i s t . F i f t e e n ot t h e 18 ' f u n c t i o n a l ' p a t i e n t s i d e n t i f i e d r e c e i v e d t h e p r i m a r y d i a g n o s i s ot "no c l e a r o r g a n i c c a u s e " . The r e m a i n i n g t h r e e were deemed t o r e p o r t d i s c o m t o r t and d i s a b i l i t y " out ot p r o p o r t i o n t o t h e d e t e c t a b l e p a t h o l o g y " . F i v e ot t h e t e m a l e s 87 and s i x ot t h e ma l e s i d e n t i t i e d as ' t u n c t i o n a i ' were a l s o c l a s s i t i e d as d i s p l a y i n g m e d i c a l l y c o n g r u e n t s i g n s and svmptoms. The r e s t d i s p l a y e d m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms and t h u s , were n o t d i t t e r e n t i a t e d by t h e p r e s e n c e or a b s e n c e ot m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms. T h e s e ' t u n c t i o n a i ' p a t i e n t s were compared on a l l m e a s u r e s to a r a n d o m l y s e l e c t e d c o n t r o l g r o u p and a p a i n g r o u p who had r e c e i v e d o r g a n i c d i a g n o s e s ( i . e . , ' o r g a n i c ' p a t i e n t s ) . Group d i t t e r e n c e s were a n a l y s e d u s i n g u n i v a r i a t e a n a l y s e s t o r a l l t h e v a r i a b l e s . I t i s r e c o g n i z e d t h a t t h i s does n o t r e p r e s e n t a c o n s e r v a t i v e e x a m i n a t i o n ot t h e d a t a , however, t h e i n t e n t i o n was t o e x p l o r e p o s s i b l e t r e n d s and t o g e n e r a t e new r e s e a r c h g o a l s . . C o n t i n u o u s d e m o g r a p h i c d a t a were a n a l y s e d u s i n g two-way (3 X 2) ANOVAs and c a t e g o r i c a l d a t a w i t h C h i S q u a r e s t a t i s t i c s . No s i g n i t i c a n t main e t t e c t s o r i n t e r a c t i o n s emerged on any ot t h e s e v a r i a b l e s w h i c h i n c l u d e d age, s o c i o e c o n o m i c s t a t u s , and e t h n i c i t y . M a r i t a l s t a t u s , however, 2 a g a i n emerged as a g r o u p d i t t e r e n c e f X ~ ( 2 ) = y . 4 5 , p<.U1 1 r e t l e c t i n g t h a t t h e n o r m a l c o n t r o l g r o u p were m o s t l y s i n g l e . P a t i e n t c h a r a c t e r i s t i c s ( d u r a t i o n ot c o n d i t i o n , m e d i c a t i o n s t r e n g t h , p h y s i c a l i m p a i r m e n t , and s u b j e c t i v e d i s a b i l i t y ) were a n a l y s e d s i m i l a r l y w i t h two-way ANOVAs t o r c o n t i n u o u s v a r i a b l e s and n o n p a r a m e t r i c s t a t i s t i c s t o r the c a t e g o r i c a l v a r i a b l e ( p r e s e n c e ot p r e v i o u s s u r g e r y ) . No g r o u p or sex d i t t e r e n c e s a r o s e on any ot t h e s e a n a l y s e s , however, a g r o u p by sex i n t e r a c t i o n was t o u n d t o r t h e r e p o r t e d d u r a t i o n 88 of t h e o a i n c o n d i t i o n s [ F ( l , 3 2 ) = 4 . 3 7 , p_< . 05) . E x a m i n a t i o n o f the means r e v e a l e d t h a t women i n t h e g r o u p w i t h o u t o r g a n i c d i a g n o s e s r e p o r t e d l o n g e r d u r a t i o n s of h a v i n g t h e p a i n p r o b l e m t h a n t h e men. W i t h i n t h e g r o u p of p a t i e n t s who had r e c e i v e d o r g a n i c d i a g n o s e s , men r e p o r t e d l o n g e r d u r a t i o n s o f t h e i r p a i n p r o b l e m t h a n t h e women. Of n o t e , t h e r e were no d i f f e r e n c e s w i t h r e s p e c t t o t h e l e v e l s of s u b j e c t i v e d i s a b i l i t y o r o b j e c t i v e p h y s i c a l i m p a i r m e n t . Means and s t a n d a r d d e v i a t i o n s of t h e above p a t i e n t c h a r a c t e r i s t i c s a r e p r e s e n t e d i n T a b l e 2 5. Tab 1e 2 5. P a t i e n t C h a r a c t e r i s t i c s : Means and S t a n d a r d D e v i a t i o n s D i a g n o s t i c G r o u p s Var i a b l e Func t i ona1 M a l e s F e m a l e s O r g a n i c M a l e s F e m a l e s D u r a t i o n (years') x sd M e d i c a t i o n S t r e n g t h x sd Sub j e c t i v e D i s a b i l i t y x sd Phys i c a1 Impairment' x sd 70 28 44 73 26.56 17.73 16.25 4.65 14.07 14.52 .33 . 7 1 36.00 15.94 13.00 7 .80 14.56 9.02 1.22 1.39 30 . 00 12.00 15.50 5.45 8.95 12.23 .67 . 87 37.67 7.94 12.00 12.73 n=9 p e r c e l l ; ( a ) u n e q u a l n T a b l e 2 6. P a i n M e a s u r e s : Means and U n i v a r i a t e A n a l y s e s by D i a g n o s t i c Groups Group S o u r c e C o n t r o l F u n c t i o n a l O r g a n i c Group Sex Group X Sex V a r i a b l e M a l e s Females M a l e s F e m a l e s M a l e s F e m a l e s F ( 2 , 4 8 ) £ F ( l , 4 8 ) £ F ( 2 , 4 8 ) £ T h r e s h o l d 2 ( m c a l / s e x / c m - ) x 2b2.68 261.94 248.77 244.80 277.60 297.00 sd 29.00 42.43 25.60 31.33 52.88 29.54 5.68 .006 .22 .623 .54 .584 x sd B e t a Sub j e P a i n x sd c t i v e Rat i n g x sd 2 . 38 .65 40.43 29.00 1 7 78 2.49 . 69 20.38 42.43 09 7 1 2 . 26 78 9.74 2 5.60 3 1 74 2.40 . 64 2 . 1 9 3 1 3 6 33 - . 04 . 7 1 09 44 24.02 5 2.88 - . 35 .99 2.84 . 70 49.43 29.54 . 48 1.19 20 .820 3.57 .065 1.41 .255 3.43 .040 .49 .486 3.50 .038 .35 .708 3.68 .061 .64 .538 n=9 per c e l l ( a ) p r e s e n t e d as z - s c o r e s oo 9 0 Group D i t t e r e n c e s : P a i n M e a s u r e s The r e s u l t s ot t h e u n i v a r i a t e a n a l y s e s on t h e p a i n m e a s u r e s a r e p r e s e n t e d i n T a b l e 2 6. A s i g n i f i c a n t g r o u p d i f f e r e n c e was f o u n d t o r p a i n t h r e s h o l d [ F ( 2 , 4 8 ) = 5 . 6 8 , D < . U 1 ) ] and t o r t h e mean p a i n r e p o r t c r i t e r i o n ( b e t a ) f F ( 2 , 4 8 ) = 3 . 4 3 , j> <.U5 1 . The Newman-Keuls M u l t i p l e C o m p a r i s o n p r o c e d u r e ( t w o - t a i l e d ) was u s e d t o i d e n t i t y where t h e d i t t e r e n c e s e x i s t e d . The mean p a i n t h r e s h o l d t o r t h e ' o r g a n i c ' g r o u p was s i g n i f i c a n t l y g r e a t e r t h a n b o t h t h e ' f u n c t i o n a l ' and n o r m a l c o n t r o l g r o u p s (jp_<.U5). The mean p a i n t h r e s h o l d t o r t h e ' t u n c t i o n a i ' g r o u p was l o w e r t h a n the n o r m a l c o n t r o l g r o u p , however, t h e d i f f e r e n c e was n o t s i g n i f i c a n t . The ' o r g a n i c ' g r o u p s e t a s i g n i f i c a n t l y h i g h e r mean c r i t e r i o n t o r e p o r t p a i n t h a n t h e ' f u n c t i o n a l ' g r o u p . A l t h o u g h t h e n o r m a l c o n t r o l g r o u p had a mean c r i t e r i o n l e v e l i n b e t w e e n t h e two p a t i e n t g r o u p s , t h e d i t t e r e n c e s were n o t s i g n i f i c a n t . T h e r e were no s t a t i s t i c a l l y s i g n i f i c a n t sex d i t t e r e n c e s , however, a p o s s i b l e t r e n d e x i s t e d on d' ( s e n s o r y d i s c r i m i n a t i o n ) w i t h f e m a l e s b e i n g s l i g h t l y b e t t e r a b l e to d i s t i n g u i s h h e a t t r o m t a i n t p a i n . An a d d i t i o n a l t r e n d d i f f e r e n t i a t i n g t h e s e x e s a p p e a r e d on t h e s u b j e c t i v e r a t i n g s ot t h e p a i n s t i m u l i w i t h f e m a l e s r a t i n g t h e s t i m u l i as s l i g h t l y more i n t e n s e and d i s t r e s s i n g t h a n t h e m a l e s . A s i g n i f i c a n t g r o u p by sex i n t e r a c t i o n a p p e a r e d w i t h t h e p a i n r e p o r t c r i t e r i o n ( b e t a ) s u g g e s t i n g , as i n t h e t i r s t s e t ot a n a l y s e s , t h a t a l t h o u g h men w i t h o u t c h r o n i c p a i n t e n d t o be l e s s l i k e l y t o r e p o r t p a i n t u l s e n s a t i o n s t h a n women, men w i t h T a b l e 2 7. C o g n i t i v e M e a s u r e s : Means and U n i v a r i a t e A n a l y s e s by D i a g n o s t i c Group P a t i e n t Group S o u r c e F u n c t i o n a l O r g a n i c Group Sex Group X Sex V a r i a b l e M a l e s F e m a l e s M a l e s Females F ( l , 2 2 ) £ F ( l , 2 2 ) £ F ( l , 2 2 ) £ C o n t e n t x 20.22 30.89 sd 11.64 12.44 P r o c e s s x 41.11 54.56 sd 16.19 14.29 E f f i c a c v x sd C a t a s t r o - p h i z i n g x sd B e h a v i o u r x sd 6.33 2.29 8.33 7.62 6.22 2.54 8.67 8.23 11.89 18.67 2.47 5.07 16.89 24.00 9.35 11.40 39.33 45.78 8.57 11.71 4.33 2.45 7.33 4.61 6.22 1.39 9.22 9.34 12.44 13.56 8.03 6.25 1.85 .18 3 5.60 .024 .22 .639 1.48 .233 5.26 .029 .65 .426 1.83 .185 1.45 .238 1.83 .185 01 .933 .18 .673 09 .768 1.38 .249 4.14 .050 2.13 .154 n=9 per c e l l 9 2 c h r o n i c p a i n a r e more l i k e l y t h a n women t o r e p o r t p a i n t u l s e n s a t i o n s . No i n t e r a c t i o n s were e v i d e n t on any ot t h e o t h e r v a r i a b l e s . Group D i t t e r e n c e s : C o g n i t i v e M e a s u r e s Means and r e s u l t s ot t h e u n i v a r i a t e a n a l y s e s t o r t h e C o p i n g S t r a t e g y Q u e s t i o n n a i r e a p p e a r i n T a b l e 27. No g r o u p d i t t e r e n c e s o r g r o u p by sex i n t e r a c t i o n s a p p e a r e d on any ot th e m e a s u r e s . A s i g n i f i c a n t sex d i t t e r e n c e emerged on the s e 1 t - r e p o r t e d use ot c o p i n g s t r a t e g i e s w i t h s p e c i t i c c o g n i t i v e c o n t e n t , s t y l e s ot c o g n i t i v e c o p i n g s t r a t e g i e s , and the use ot b e h a v i o u r a l s t r a t e g i e s . E x a m i n a t i o n ot t h e means r e v e a l e d t h a t on a l l t h r e e m e a s u r e s women r e p o r t e d u s i n g t h e c o p i n g s t r a t e g i e s more t h a n men.' Group D i t t e r e n c e s : A t i e c t i v e M e a s u r e s Means and u n i v a r i a t e a n a l y s e s t o r t h e a t t e c t i v e m e a s u r e s a r e p r e s e n t e d i n T a b l e 28. No s i g n i t i c a n t main e t t e c t s or g r o u p by sex i n t e r a c t i o n s were e v i d e n t on any ot t h e t h r e e m e a s u r e s . However, a p o s s i b l e t r e n d d i t t e r e n t i a t i n g t h e s e x e s a p p e a r e d on e m o t i o n a l i t y w i t h women s l i g h t l y more i n c l i n e d t o r e p o r t h i g h e r l e v e l s ot e m o t i o n a l i t y r e g a r d i n g t h e i r c h r o n i c p a i n p r o b l e m . Group D i t t e r e n c e s : M e a s u r e s ot M e d i c a l l y I n c o n g r u e n t Symptoms I t was ot i n t e r e s t t o see i t t h e t h r e e m e a s u r e s ot m e d i c a l l y i n c o n g r u e n t symptoms d i s t i n g u i s h e d p a t i e n t s w i t h o u t o r g a n i c d i a g n o s e s t r o m t h o s e w i t h o r g a n i c d i a g n o s e s . No main e t t e c t s o r i n t e r a c t i o n s a p p e a r e d on any ot t h e t h r e e m e a s u r e s T a b l e 28. A t t e c t i v e M e a s u r e s : Means and U n i v a r i a t e A n a l y s e s by D i a g n o s t i c Group Group S o u r c e C o n t r o l F u n c t i o n a l O r g a n i c Group Sex Group X Sex V a r i a b l e M a l e s Females M a l e s Females M a l e s F e m a l e s F ( l , 2 2 ) £ F ( l , 2 2 ) £ F ( 1 , 2 2 ) £ T r a i t a A n x i e t y x 35.89 31.89 33.33 36.22 39.56 37.33 sd 7.86 5.35 6.12 9.44 10.04 . 6.44 Wo r r y x 2.63 2.78 3.27 3.10 sd 1.31 1.80 .74 1.40 Emo t i o n - a 1 i t y x 1.73 2.80 2.58 3.24 sd 1.12 1.68 1.26 1.28 1.75 .184 .28 .600 .96 .390 1.10 .302 .00 .980 .12 .732 2.03 .164 3.64 .065 .21 .646 (a) F c a l u l a t e d w i t h (2,48) d e g r e e s of freedom, f o r g r o u p and ( 1 , 4 8 ) t o r sex n=9 per c e l l u> T a b l e 28. Measures ot M e d i c a l l y I n c o n g r u e n t Symptoms: Means and U n i v a r i a t e A n a l y s e s by D i a g n o s t i c Group P a t i e n t Group S o u r c e Func t i ona1 O r g a n i c Group Sex Group X Sex V a r i a b l e M ales F e m a l e s M a l e s Females F ( l , 3 2 ) £ F ( l , 3 2 ) £ F ( l , 3 2 ) £ P a i n D r aw i ng x sd N o n - o r g a n i c P h y s i c a l S i g n s x sd I n a p p r o p r i a t e S ym p t oms x sd 2.67 3.27 .67 1.03 2 .00 1.79 3.38 3.25 .88 1.46 2.25 1.67 1 . 00 1.16 1 4 38 1.86 1 . 68 5.20 4.38 40 89 3.20 1.64 .12 .735 1.86 .182 1.43 .245 .31 .586 04 .836 1.08 .306 46 .500 .00 .954 39 .537 n=9 per c e l l 4>- 95 s u g g e s t i n g t h a t t h e y a r e i n d e e d a s s e s s i n g d i t t e r e n t c o n s t r u c t s ot a c h r o n i c p a i n p r o b l e m ( s e e T a b l e 2 9 ) . G i v e n t h e v e r y s m a l l n and o b v i o u s lack, ot power, t h e o n l y p o s s i b l e e x c e p t i o n may be t h e N o n o r g a n i c P h y s i c a l S i g n s w h i c h seems t o i n d i c a t e a p o s s i b l e t r e n d . E x a m i n a t i o n ot t h e means shows t h a t t h e g r o u p w i t h o u t c l e a r o r g a n i c d i a g n o s e s t e n d t o e x h i b i t more n o n o r g a n i c p h y s i c a l s i g n s . 96 Summary ot F i n d i n g s The r e s u l t s ot t h i s s t u d y may be summarized as f o l l o w s : 1) T h e r e were no d i t t e r e n c e s between c h r o n i c p a i n g r o u p s and t h e n o r m a l c o n t r o l g r o u p on t h e d e m o g r a p h i c v a r i a b l e s ( a g e , s o c i o e c o n o m i c s t a t u s , e t h n i c i t y , and employment s t a t u s ) e x c e p t t o r m a r i t a l s t a t u s . The n o r m a l c o n t r o l g r o u p c o n s i s t e d l a r g e l y ot s i n g l e p e o p l e whereas t h e p a t i e n t g r o u p s were m o s t l y m a r r i e d or i n v o l v e d i n common-law r e l a t i o n s h i p s . 2) The c o m p a r i s o n ot p a i n - t r e e i n d i v i d u a l s w i t h t h e p a i n p a t i e n t s p o o l e d as a g e n e r a l g r o u p r e v e a l e d no s i g n i f i c a n t g r o u p e f f e c t s t o r t h e p a i n m e a s u r e s . 3 ) The d i s t i n c t i o n ot p a i n p a t i e n t s i n t o t h o s e w i t h and w i t h o u t m e d i c a l l y i n c o n g r u e n t symptoms y i e l d e d s i g n i f i c a n t g r o u p d i f f e r e n c e s o n l y on a measure ot s u b j e c t i v e d i s a b i l i t y . T h o s e p a t i e n t s who e x h i b i t e d m e d i c a l l y i n c o n g r u e n t symptoms a l s o r e p o r t e d g r e a t e r s u b j e c t i v e d i s a b i l i t y t h a n t h e p a t i e n t s who d i d n o t e x h i b i t i n c o n g r u e n t symptoms. T h e r e were no s i g n i t i c a n t g r o u p d i t t e r e n c e s on m e a s u r e s ot p a i n p e r c e p t i o n , c o p i n g s t r a t e g i e s , o r a t t e c t i v e d i s t r e s s . The g r o u p s a l s o d i d n o t d i t t e r on a measure ot o b j e c t i v e p h y s i c a l i m p a i r m e n t nor d i d t h e c l a s s i f i c a t i o n s y s t e m d i s t i n g u i s h between ' o r g a n i c ' and ' f u n c t i o n a l ' d i a g n o s t i c g r o u p s . 4 ) The d i s t i n c t i o n ot p a i n p a t i e n t s a c c o r d i n g to ' o r g a n i c ' vs ' f u n c t i o n a l ' d i a g n o s t i c g r o u p s y i e l d e d s i g n i t i c a n t g r o u p d i f f e r e n c e s on m e a s u r e s ot p a i n t h r e s h o l d and p a i n r e p o r t c r i t e r i o n ( b e t a ) . P a t i e n t s w i t h ' o r g a n i c ' d i a g n o s e s had h i g h e r p a i n t h r e s h o l d s and h i g h e r p a i n r e p o r t 97 c r i t e r i a t h a n b o t h t h e c o n t r o l g r o u p and t h e ' f u n c t i o n a l ' p a t i e n t g r o u p , w h i c h had l o w e r p a i n t h r e s h o l d s and c r i t e r i a t o r e p o r t p a i n—- t h a n t h e c o n t r o l g r o u p - The c r i t e r i o n t o r e p o r t p a i n d i t t e r e d s i g n i t i c a n t l y between t h e two p a t i e n t g r o u p s o n l y , however. T h e r e were no g r o u p d i t t e r e n c e s on d i s a b i l i t y , o b j e c t i v e p h y s i c a l i m p a i r m e n t , t h e p r e s e n c e ot m e d i c a l l y i n c o n g r u e n t symptoms, s e l t - r e p o r t e d use ot c o p i n g s t r a t e g i e s o r on me a s u r e s ot a n x i e t y . F i n a l l y , t h e r e was a s i g n i f i c a n t g r o u p by sex i n t e r a c t i o n t o r t h e r e p o r t e d d u r a t i o n ot t h e p a i n c o n d i t i o n s . Women w i t h o u t c l e a r o r g a n i c d i a g n o s e s r e p o r t e d l o n g e r d u r a t i o n s ot t h e i r p a i n c o n d i t i o n s t h a n men, whereas men w i t h ' o r g a n i c ' d i a g n o s e s r e p o r t e d l o n g e r d u r a t i o n s ot c h r o n i c p a i n t h a n women. 5) S i g n i t i c a n t sex d i t t e r e n c e s were f o u n d t o r s e l t - r e p o r t e d s u b j e c t i v e d i s a b i l i t y w i t h women r e p o r t i n g g r e a t e r l o s s ot f u n c t i o n t h a n men. Gender d i t t e r e n c e s were a l s o e v i d e n t t o r t h e me a s u r e s ot d' and s u b j e c t i v e r a t i n g ot p a i n . T h a t i s , women were more c o n s i s t e n t i n d i s t i n g u i s h i n g h e a t trom t h e f i r s t t r a c e ot p a i n and j u d g e d t h e s t i m u l i to be more i n t e n s e and u n p l e a s a n t t h a n men. A d d i t i o n a l l y , t h e r e was a t r e n d t o r women t o adm i t t o u s i n g c o g n i t i v e c o p i n g s t r a t e g i e s , where c o g n i t i o n s a r e d i v e r t e d t o o t h e r m e n t a l a c t i v i t i e s , and b e h a v i o u r a l c o p i n g s t r a t e g i e s more o t t e n t h a n men. Women r e p o r t e d g r e a t e r e t t i c a c y t o manage t h e i r p a i n ( i . e . , d e c r e a s e o r c o n t r o l t h e p a i n ) t h a n men. F i n a l l y , a s i g n i f i c a n t g r o u p by sex i n t e r a c t i o n was f o u n d t o r t h e measure ot p a i n r e p o r t c r i t e r i o n when t h e p a i n p a t i e n t s were p o o l e d i n t o one g r o u p . 98 W i t h i n t h e n o r m a l c o n t r o l g r o u p , women s e t l o w e r p a i n r e p o r t c r i t e r i a t h a n men but w i t h i n t h e c h r o n i c p a i n g r o u p s , women s e t h i g h e r p a i n r e p o r t c r i t e r i a t h a n men. 6 ) The t h r e e m e a s u r e s ot m e d i c a l l y i n c o n g r u e n t symptom p r e s e n t a t i o n were u n r e l a t e d t o m e a s u r e s ot p a i n p e r c e p t i o n but d i d show some a s s o c i a t i o n t o t h e c o g n i t i v e and a t t e c t i v e v a r i a b l e s . A l l t h r e e were p o s i t i v e l y a s s o c i a t e d w i t h c a t a s t r o p h i z i n g and w i t h t h e use ot c o p i n g s t r a t e g i e s r e t l e c t i n g s p e c i t i c c o g n i t i v e c o n t e n t s u c h as p r a y i n g , h o p i n g , and, g e n e r a l l y d i v e r t i n g a t t e n t i o n t o o t h e r m e n t a l e v e n t s . The P a i n D r a w i n g and N o n - o r g a n i c P h y s i c a l S i g n s were p o s i t i v e l y a s s o c i a t e d i n a s m a l l way w i t h c o p i n g s t r a t e g i e s r e t l e c t i n g t h e c o n s c i o u s use ot c o p i n g . s t y l e s s u c h as i g n o r i n g and r e i n t e r p r e t i n g t h e p a i n s e n s a t i o n s and u s i n g c o p i n g s e l t s t a t e m e n t s . The I n a p p r o p r i a t e Symptom I n v e n t o r y t o r m e d a s m a l l n e g a t i v e a s s o c i a t i o n w i t h a measure ot t h e p a t i e n t ' s p e r c e p t i o n ot h i s / h e r e t t i c a c y t o manage ( i . e . , c o n t r o l and d e c r e a s e ) t h e p a i n . Ot n o t e , o n l y t h e P a i n D r a w i n g was p o s i t i v e l y a s s o c i a t e d w i t h a l l t h r e e m e a s u r e s ot a t t e c t ( g e n e r a l a n x i e t y , and w o r r y and e m o t i o n a l i t y s p e c i t i c t o c h r o n i c p a i n ) . 7) The me a s u r e s ot s e v e r i t y ot t h e p a i n c o n d i t i o n ( P h y s i c a l I mpairment Index and O s w e s t r y D i s a b i l i t y Q u e s t i o n n a i r e ) were u n r e l a t e d t o m e a s u r e s ot p a i n p e r c e p t i o n . However, a p o s i t i v e a s s o c i a t i o n was t o u n d t o r b o t h m easures w i t h t h e use ot c o p i n g s t r a t e g i e s ot s p e c i t i c m e n t a l c o n t e n t ( p r a y i n g , h o p i n g , and d i s t r a c t i o n t o o t h e r m a t t e r s ) . T h e r e 99 was a s m a l l p o s i t i v e a s s o c i a t i o n between s u b j e c t i v e d i s a b i l i t y and c a t a s t r o p h i z i n g and t h e use ot c o n s c i o u s c o g n i t i v e c o p i n g s t y l e s . F i n a l l y , o b j e c t i v e p h y s i c a l i m p a i r m e n t was p o s i t i v e l y a s s o c i a t e d t o w o r r y s p e c i t i c t o c h r o n i c p a i n ( e . g . , "I w o r r y a b o u t my t a m i l y " ) and s u b j e c t i v e d i s a b i l i t y was p o s i t i v e l y r e l a t e d t o e m o t i o n a l i t y a b o u t th e p a i n ( e . g . , " I t h i n k , ' T h i s p a i n i s d r i v i n g me c r a z y ' " ) . 8) The m e a s u r e s ot p a i n p e r c e p t i o n were m o s t l y u n r e l a t e d t o c o g n i t i v e and a t t e c t i v e v a r i a b l e s w i t h t h e e x c e p t i o n ot a s m a l l n e g a t i v e r e l a t i o n s h i p between p a i n t h r e s h o l d and t h e use ot c o p i n g t a c t i c s ot d i v e r t i n g a t t e n t i o n t o o t h e r m e n t a l c o n t e n t . T h a t i s , t h o s e w i t h l o w e r t h r e s h o l d s r e p o r t e d g r e a t e r use ot p r a y i n g , h o p i n g , and a t t e m p t s t o c o n c e n t r a t e on o t h e r m a t t e r s . A d d i t i o n a l l y , t h o s e who were i n c l i n e d to c a t a s t r o p h i z e a b o u t t h e i r p a i n a l s o r e p o r t e d g r e a t e r s u b j e c t i v e e x p e r i e n c e s ot t h e s e n s o r y i n t e n s i t y ot t h e p a i n s t i m u l i . Worry and e m o t i o n a l i t y a b o u t t h e p a i n were a l s o a s s o c i a t e d w i t h h i g h e r r a t i n g s ot t h e s e n s o r y i n t e n s i t y ot p a i n , a l t h o u g h t o a l e s s e r d e g r e e . F i n a l l y , c a t a s t r o p h i z i n g t o rmed a s t r o n g p o s i t i v e a s s o c i a t i o n w i t h a l l t h r e e m e asures ot a t t e c t ( g e n e r a l a n x i e t y , w o r r y , and e m o t i o n a l i t y ) . IDO DISCUSSION P a i n P e r c e p t i o n i n C h r o n i c P a i n P a t i e n t s The r e s u l t s ot t h e p r e s e n t i n v e s t i g a t i o n c o n t i r m t h e e x p e c t a t i o n t h a t c h r o n i c p a i n p a t i e n t s , as a h e t e r o g e n e o u s sample i n terms ot t h e i r c l i n i c a l p r e s e n t a t i o n , do n o t have a l t e r e d p a i n p e r c e p t i o n . T h e r e were no d i t t e r e n c e s between p a i n - t r e e i n d i v i d u a l s and t h e e n t i r e sample ot c h r o n i c p a i n p a t i e n t s on m e a s u r e s ot p a i n t h r e s h o l d , d i s c r i m i n a b i l i t v ( s e n s o r v s e n s i t i v i t y ) , b i a s t o r e p o r t s e n s a t i o n s as p a i n t u l , o r t h e s u b j e c t i v e r a t i n g s ot p a i n i n t e n s i t y and u n p l e a s a n t n e s s . As n o t e d , th e sample ot p a i n p a t i e n t s was m i x e d i n t e r m s ot t h e p a t i e n t s ' p a t t e r n s ot p a i n p r e s e n t a t i o n and d i a g n o s t i c g r o u p s . P a s t i n v e s t i g a t i o n s w h i c h d i d r e p o r t a l t e r e d p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s have s e l e c t e d p a i n p a t i e n t s trom r e l a t i v e l y homogeneous s a m p l e s . F o r e x a mple, some i n v e s t i g a t o r s s e l e c t e d p a t i e n t s w i t h c l e a r o r g a n i c d i a g n o s e s (Cohen e t a l . , 1983; Lipman e t a l . , 1987; N a l i b o i f e t a l . . 1981; and Yang e t a l . , 1983; 1985) and o t h e r s s e l e c t e d p a t i e n t s w i t h l e s s c l e a r p h y s i c a l p a t h o l o g y and whose p a i n c o n d i t i o n s have been f o u n d t o be h i g h l y a s s o c i a t e d w i t h s t r e s s and a n x i e t y ( B r a n d s & S c h m i d t , 1987; Malow e t a l . , 1980; Malow & O l s o n , 1981; P e t e r s e t a l . . 1989; Scudds et a l . , 1987; 1 9 8 9 ) . B e c a u s e of l i t e r a t u r e s u g g e s t i n g t h a t c o g n i t i v e a p p r a i s a l and e m o t i o n a l r e a c t i o n s ( i . e . , h e l p l e s s n e s s , c a t a s t r o p h i z i n g , and a n x i e t y ) t o c h r o n i c p a i n c o n t r i b u t e more t o t h e v a r i a n c e i n p a i n p e r c e p t i o n and d i s a b i l i t y t h a n does the d e g r e e of 101 a p p a r e n t p h y s i c a l p a t h o l o g y , i t was e x p e c t e d t h a t the d i s t i n c t i o n of p a t i e n t s i n t o two g r o u p s on t h e b a s i s o f t h e p r e s e n t a t i o n of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms would y i e l d r e s u l t s s i m i l a r t o t h e two g r o u p s of i n v e s t i g a t i o n s r e f e r r e d t o above ( B a r n e s e t a l . , 1989; F l o r & T u r k , 1987; L a c r o i x e t a l . , 1990; Lee e t a l . , 1989; M a i n & W a d d e l l , 1984; P o l a t i n e t a l . , 1989; T u r k & Rudy, 1987; and W a d d e l l , 1987). P a t i e n t s e x h i b i t i n g m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms were e x p e c t e d t o be h y p e r v i g i l a n t f o r p a i n f u l s e n s a t i o n s and t h e r e f o r e , t o be more r e s p o n s i v e t o p a i n f u l s t i m u l i ( i . e . , have l o w e r p a i n t h r e s h o l d s and l o w e r c r i t e r i a t o l a b e l s e n s a t i o n s as p a i n f u l ) . T h o s e p a t i e n t s who d i d n o t e x h i b i t s i g n s and symptoms i n c o n g r u e n t w i t h u n d e r l y i n g anatomy and p h y s i o l o g y were e x p e c t e d t o be l e s s r e s p o n s i v e t o p a i n f u l s t i m u l i ( i . e . , have h i g h e r p a i n t h r e s h o l d s and h i g h e r c r i t e r i a t o l a b e l s e n s a t i o n s as p a i n f u l ) i n a c c o r d a n c e w i t h t h e p r e d i c t i o n s of t h e a d a p t a t i o n - 1 e v e 1 m o d e l . However, the d i s t i n c t i o n o f p a i n p a t i e n t s i n t o t h o s e w i t h and w i t h o u t m e d i c a l l y i n c o n g r u e n t symptoms d i d n o t d i f f e r e n t i a t e t h e g r o u p s on m e a s u r e s o f p a i n p e r c e p t i o n as h y p o t h e s i z e d . R a t h e r , th e d i s t i n c t i o n of p a i n p a t i e n t s i n t o g r o u p s b a s e d on the p r e s e n c e o r a b s e n c e o f a d i a g n o s a b l e o r g a n i c c a u s e d i f f e r e n t i a t e d t h e p a t i e n t s i n t h e i r r e s p o n s e s t o p a i n f u l s t i m u l i . P a t i e n t s w i t h c l e a r o r g a n i c f i n d i n g s had s i g n i f i c a n t l y h i g h e r p a i n t h r e s h o l d s t h a n b o t h t h e c o n t r o l g r o u p and t h e p a t i e n t s w i t h o u t a p p a r e n t o r g a n i c e t i o l o g y . The r e s p o n s e s of t h e ' o r g a n i c ' p a t i e n t s c o n f o r m e d t o t h e 1 0 2 p r e d i c t i o n of t h e a d a p t a t i o n - l e v e l m o d e l . In c o n t r a s t , p a i n p a t i e n t s w i t h no c l e a r p h y s i c a l p a t h o l o g y ( ' f u n c t i o n a l ' p a t i e n t s ) were f o u n d t o have s i g n i f i c a n t l y l o w e r p a i n t h r e s h o l d s r e l a t i v e t o t h e ' o r g a n i c ' p a t i e n t g r o u p ( i . e . , t h o s e w i t h o r g a n i c d i a g n o s e s ) . In a d d i t i o n , t h e ' f u n c t i o n a l 1 p a t i e n t s had l o w e r p a i n t h r e s h o l d s t h a n t h e n o r m a l c o n t r o l g r o u p , but t h i s d i f f e r e n c e was n o t s t a t i s t i c a l l y s i g n i f i c a n t . B e c a u s e the r e s p o n s e s o f t h e s e p a t i e n t s were n o t s i g n i f i c a n t l y d i f f e r e n t f r o m t h e n o r m a l c o n t r o l s a m p l e , t h e p r e d i c t i o n of t h e h y p e r v i g i l a n c e model was n o t s u p p o r t e d . S i g n a l d e t e c t i o n a n a l y s i s of t h e d a t a i n d i c a t e d t h a t t h e ' o r g a n i c ' p a t i e n t s s e t s i g n i f i c a n t l y h i g h e r r e s p o n s e c r i t e r i a ( i . e . , were l e s s i n c l i n e d ) t o r e p o r t s e n s a t i o n s as p a i n f u l t h a n t h e ' f u n c t i o n a l ' p a t i e n t s . The mean r e s p o n s e c r i t e r i o n f o r t h e n o r m a l c o n t r o l g r o u p was between the two p a t i e n t g r o u p s ; however, t h e c r i t e r i o n t o r e p o r t p a i n d i f f e r e d s i g n i f i c a n t l y between the two p a t i e n t s g r o u p s o n l y . No d i f f e r e n c e s were f o u n d f o r t h e d i s c r i m i n a b i l i t y measure w h i c h i n d i c a t e s t h a t t h e g r o u p s d i d not d i f f e r i n t h e i r s e n s o r y s e n s i t i v i t y t o t h e s t i m u l i . C o r r e l a t i o n a l a n a l y s e s r e v e a l e d a h i g h p o s i t i v e c o r r e l a t i o n between the p a i n t h r e s h o l d and r e s p o n s e b i a s t o r e p o r t p a i n but no r e l a t i o n s h i p t o d i s c r i m i n a b i l i t y . The f i n d i n g t h a t the t h r e s h o l d measure i s l a r g e l y r e f l e c t e d by t h e p r o p e n s i t y t o r e p o r t p a i n r a t h e r t h a n s e n s o r y s e n s i t i v i t y i s s u p p o r t e d by p r e v i o u s i n v e s t i g a t i o n s ( C l a r k . & M e h l , 1971; C l a r k & Yang, 1983; Yang e t a l . , 1 9 8 5 ) . T h i s r e s u l t has been 103 i n t e r p r e t e d as s u p p o r t t o r t h e SDT s u p p o s i t i o n t h a t d' and b e t a r e p r e s e n t i n d e p e n d e n t p a r a m e t e r s (Yang e t a l , 1 9 8 5 ) . The l i n k between ' o r g a n i c i t y ' and p a i n r e p o r t has been f o u n d i n p r e v i o u s i n v e s t i g a t i o n s . R e l a t i v e t o p e o p l e w i t h o u t c h r o n i c p a i n , h i g h e r p a i n t h r e s h o l d and t o l e r a n c e l e v e l s have been c o n s i s t e n t l y f o u n d i n c h r o n i c p a i n p a t i e n t s w i t h o b v i o u s o r g a n i c p a t h o l o g y ( Cohen e t a l . , 1983; Lipman e t a l . , 1987; N a l i b o f f e t a l . , 1981; and Yang e t a i . , 1983; 1 9 8 5 ) . In c o n t r a s t , o t h e r i n v e s t i g a t i o n s have r e p o r t e d p a i n p a t i e n t s w i t h l e s s c l e a r o r g a n i c p a t h o l o g y t o have l o w e r p a i n t h r e s h o l d s and t o l e r a n c e l e v e l s . A l t h o u g h t h e ' f u n c t i o n a l ' p a t i e n t g r o u p had l o w e r p a i n t h r e s h o l d s t h a n t h e n o r m a l c o n t r o l sample i n t h e p r e s e n t s t u d y , t h e d i f f e r e n c e was not s i g n i f i c a n t . T h i s l a c k o f s i g n i f i c a n t f i n d i n g may be a t t r i b u t a b l e t o t h e t y p e of s t i m u l u s u s e d i n t h e p r e s e n t i n v e s t i g a t i o n . P r e v i o u s r e s e a r c h p r o v i d i n g s u p p o r t f o r t h e h v p e r v i g i l a n c e model n o t o n l y a s s e s s e d c h r o n i c p a i n p a t i e n t s w i t h o u t c l e a r o r g a n i c p a t h o l o g y , but a l s o u s e d t o n i c p a i n s t i m u l i . B e c a u s e of t h e s i m i l a r i t y of t h e e x p e r i e n c e of p a i n p r o d u c e d by t o n i c p a i n i n d u c t i o n t e c h n i q u e s t o c h r o n i c p a i n c o n d i t i o n s , t h e y may be more l i k e l y t o h e i g h t e n a n x i e t y and v i g i l a n c e f o r t h o s e s e n s a t i o n s . G i v e n t h e c o n s i s t e n c y i n t h e p a t t e r n of r e s u l t s t o p r e v i o u s r e s e a r c h , i t . seems l i k e l y t h a t p a t i e n t s w i t h o u t a c l e a r o r g a n i c d i a g n o s i s may be more v u l n e r a b l e t o any p a i n s t i m u l i but p a r t i c u l a r l y t o t o n i c p a i n s t i m u 1 i . * 104 S i g n a l D e t e c t i o n i n v e s t i g a t i o n s ot p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s a r e g e n e r a l l y c o n s i s t e n t w i t h t h e p r e s e n t s t u d y i n t h e f i n d i n g t h a t p a t i e n t s w i t h c l e a r o r g a n i c d y s f u n c t i o n have a h i g h e r p a i n r e p o r t c r i t e r i o n t h a n n o r m a l c o n t r o l s u b j e c t s , and t h a t p a t i e n t s w i t h l e s s o b v i o u s p h y s i c a l p a t h o l o g y t e n d t o have a l o w e r p a i n r e p o r t c r i t e r i o n t h a n p e o p l e w i t h o u t c h r o n i c p a i n ( C o h e n e t a l . , 1983; Malow et a l . , 1980; Malow & O l s o n , 1981; N a l i b o f f e t a l . , 1981; and Yang e t a l . , 1983; 1 985 ). The r e s u l t s of t h e p r e s e n t s t u d y r e v e a l e d t h a t t h e d i f f e r e n c e s i n p a i n t h r e s h o l d were p r i m a r i l y a s s o c i a t e d w i t h d i f f e r e n c e s i n t h e r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s as p a i n f u l . However, t h e r e s u l t s o f t h e p r e s e n t i n v e s t i g a t i o n d i f f e r f r o m p a s t SDT s t u d i e s on c h r o n i c p a i n p o p u l a t i o n s w i t h r e s p e c t t o t h e d i s c r i m i n a b i l i t y of t h e p a i n s t i m u l i . A l l of t h e p r e v i o u s SDT s t u d i e s f o u n d s i g n i f i c a n t d i f f e r e n c e s between c h r o n i c p a i n p a t i e n t s and p e o p l e w i t h o u t c h r o n i c p a i n on t h e measure of d i s c r i m i n a b i l i t y , w i t h c h r o n i c p a i n p a t i e n t s b e i n g l e s s a b l e t o d i s c r i m i n a t e between s t i m u l i ( C o hen e t a l . , 1983; Malow e t a l . , 1980; Malow S. O l s o n , 1981; N a l i b o f f e t a l . , 1981; Yang et a l . , 1983; 1 9 8 5 ) . In c o n t r a s t , s i g n i f i c a n t d i f f e r e n c e s were not f o u n d on t h e d i s c r i m i n a b i l i t y measure i n t h e p r e s e n t i n v e s t i g a t i o n . The d i s c r e p a n c y i n f i n d i n g s c o n c e r n i n g the d' measure between t h i s r e s e a r c h and p a s t i n v e s t i g a t i o n s may be due t o a number of f a c t o r s . F i r s t , t h e p r e s e n t i n v e s t i g a t i o n e x e r t e d g r e a t e r c o n t r o l o v e r m e d i c a t i o n t h a n was done i n p r e v i o u s r e s e a r c h . T h e r e i s good r e a s o n t o b e l i e v e t h a t a l a c k of 105 c o n t r o l o v e r m e d i c a t i o n c o u l d b i a s f i n d i n g s . Yang et a 1. , (1979) f o u n d t h a t t h e a d m i n i s t r a t i o n o f m o r p h i n e r e s u l t e d i n an i n c r e a s e i n p a i n t h r e s h o l d and r e s p o n s e b i a s and a d e c r e a s e i n d i s c r i m i n a b i l i t y of r a d i a n t h e a t s t i m u l i . V a l i u m was f o u n d t o r e s u l t i n i n c r e a s e d r e s p o n s e c r i t e r i o n t o r e p o r t s e n s a t i o n s as p a i n f u l o n l y and a p l a c e b o c o n t r o l d i d n o t r e s u l t i n s i g n i f i c a n t a l t e r a t i o n s i n p a i n r e s p o n s i v e n e s s o v e r t i m e . Most of t h e SDT s t u d i e s i n v e s t i g a t i n g p a i n p e r c e p t i o n i n c h r o n i c p a i n p a t i e n t s d i d n o t m e n t i o n the use of m e d i c a t i o n b y t h e i r p a i n p o p u l a t i o n and i t c a n n o t be assumed t h a t t h e p a t i e n t s were n o t t a k i n g any m e d i c a t i o n f o r t h e i r p a i n a t t h e t i m e o f t e s t i n g (Cohen e t a l . , 1983; Malow et a l . , 1980; N a l i b o f f e t a l . , 1 9 8 1 ) . Yang e t a l . , ( 1985) r e p o r t e d that- the p a i n p a t i e n t s t h e y t e s t e d were r e q u e s t e d not t o t a k e any p a i n m e d i c a t i o n on t h e day of t e s t i n g and t h e y e s t i m a t e d t h a t a l l p a t i e n t s were m e d i c a t i o n - f r e e f o r a t l e a s t e i g h t h o u r s . The minimum amount of t i m e l a p s i n g i n the p r e s e n t i n v e s t i g a t i o n f o r m e d i c a t i o n i n t a k e was n i n e h o u r s ; however, the m a j o r i t y of t h e p a t i e n t s t e s t e d i n t h e p r e s e n t i n v e s t i g a t i o n were n o t t a k i n g any r e g u l a r m e d i c a t i o n a t a l l and t h u s , may r e p r e s e n t a ' c l e a n e r ' s a m p l e . T h i s c o u l d be an a r t i f a c t o f t h e s e l e c t i o n c r i t e r i a ( i . e . , b e c a u s e p a t i e n t s were r e q u e s t e d t o n o t t a k e t h e i r m e d i c a t i o n f r o m m i d n i g h t th e n i g h t b e f o r e t e s t i n g , p a t i e n t s who d i d n o t t a k e m e d i c a t i o n anyway were more l i k e l y to v o l u n t e e r ) . T h e r e f o r e , t h e p o s s i b l e e x i s t e n c e o f a n a l g e s i c m e d i c a t i o n i n t h e o a i n D o o u l a t i o n s of u a s t SDT s t u d i e s mav 106 have c o n t r i b u t e d t o t h e i r p o o r e r d i s c r i m i n a b i l i t y of p a i n f u l s t i m u l i i n c o n t r a s t t o t h e r e s u l t s of t h i s s t u d y . A s e c o n d f a c t o r t h a t may have c o n t r i b u t e d to d i f f e r e n c e s i n r e s u l t s i n t h e d' measure a l s o c o n c e r n s t h e s e l e c t i o n c r i t e r i a f o r s u b j e c t s . B e c a u s e a r e l a t i o n s h i p between age and d i s c r i m i n a b i l i t y has been r e p o r t e d i n p a s t r e s e a r c h ( C l a r k & M e h l , 1971), s u b j e c t s were s e l e c t e d f o r t h e p r e s e n t s t u d y who were between t h e ages o f 30 and 60 y e a r s and t h e g r o u p s were matched f o r a g e . In f a c t , a s m a l l but s i g n i f i c a n t n e g a t i v e c o r r e l a t i o n was f o u n d between age and d' i n t h e p r e s e n t s t u d y (_r = -.25, £ < . 01 , n = 90) s u g g e s t i n g t h a t o l d e r s u b j e c t s showed p o o r e r d i s c r i m i n a b i l i t y of the s t i m u l i . Malow e t a l . (1980) t e s t e d c h r o n i c p a i n p a t i e n t s whose mean age was 28 y e a r s ( s.d.=9.1) and compared t h e i r r e s p o n s e s to t h e c o n t r o l g r o u n whose mean age was 19 y e a r s ( s . d.=1 .2 ) . C h r o n i c p a i n p a t i e n t s t e s t e d i n t h e Yang e t a l . (1985) s t u d y r a n g e d i n age f r o m 26 t o 70 y e a r s whereas the c o n t r o l s u b j e c t s r a n g e d i n age f r o m 18 t o 65 y e a r s . O t h e r i n v e s t i g a t i o n s d i d n o t r e p o r t t h e ages o f t h e i r s u b j e c t s ( N a l i b o f f et a l . , 1981; Malow e t a l . , 1 9 8 0 ) . The t e n d e n c y f o r p a s t i n v e s t i g a t i o n s t o have t e s t e d an o l d e r p a t i e n t g r o u p and compared t h e i r r e s p o n s e s t o a y o u n g e r c o n t r o l g r o u p may have c o n t r i b u t e d t o t h e d i f f e r e n c e s f o u n d i n d i s c r i m i n a b i l i t y . C o n t r o l o v e r age d i f f e r e n c e s and m e d i c a t i o n i n t a k e may a c c o u n t f o r t h e l a c k of s i g n i f i c a n t f i n d i n g s i n t h e c u r r e n t s t u d y f o r t h e measure of d i s c r i m i n a b i l i t y . The SDT m e t h o d o l o g y used i n t h e p r e s e n t s t u d y i s n o t a b l e f o r t h e use of a c o n t r o l sample i n t h e d e f i n i t i o n of h i t s and f a l s e a l a r m s . The " f o t h e r r e s e a r c h e r s has s i g n a l d e t e c t i o n meas c u r r e n t p a r a d i g m a v o i were g i v e n t h e same s b e t a s were c a l c u l a t e d T h i s i s a c h a r a c t e r i s p a i n p e r c e p t i o n and a of g r o u p d i f f e r e n c e s f i n d i n g o f no g r o u p d more v a l i d r e p r e s e n t a c h r o n i c p a i n p a t i e n t s n o r m a l c o n t r o l g r o u p t h a n t h a t In summary, t h e r e s u l t s of p r o v i d e s u p p o r t f o r t h e a d a p t a t p e r c e p t i o n i n c h r o n i c p a i n p a t i of p a i n p a t i e n t s . The d i s t i n c t ' i n c 1 u s i o n a r y ' c r i t e r i a ( i . e . , m e d i c a l l y i n c o n g r u e n t s i g n s and g r o u p d i f f e r e n c e s i n p a i n p e r c e R a t h e r , t h e use o f ' e x c l u s i o n a r c l e a r p a t h o p h y s i o l o g i c a l c a u s e s r e s u l t e d i n t h e d i s t i n c t i o n of r e s p o n s e s t o p a i n f u l s t i m u l i , h y p o t h e s i z e d t o be r e p r e s e n t e d a h i g h e r c r i t e r i o n t o r e p o r t se c o m p a r i s o n to p a i n - f r e e p e o p l e . 107 s e l i n e u s e d by t a t i o n of t h e a t i o n s . The of t h e s u b j e c t s t h e d 1 s and o f f p o i n t s . SDT s t u d i e s of i n t e r p r e t a t i o n e c u r r e n t u r e i s l i k e l y a t i v i t y of r e l a t i v e t o t h e r e p o r t e d i n p r e v i o u s r e s e a r c h . t h e p r e s e n t i n v e s t i g a t i o n i o n - l e v e l model of p a i n e n t s , but o n l y f o r a s u b g r o u p i o n of p a t i e n t s by a s s e s s i n g i d e n t i f y i n g t h e p r e s e n c e of symptoms) d i d n o t r e s u l t i n p t i o n as h y p o t h e s i z e d , however, y' c r i t e r i a ( i . e . , a b s e n c e of f o r t h e p a i n c o n d i t i o n ) p a i n p a t i e n t s i n terms o f t h e i r The a d a p t a t i o n - 1 e v e 1 model was by a h i g h e r p a i n t h r e s h o l d and n s a t i o n s as p a i n f u l i n T h i s p r e d i c t i o n was met by l o a t i n g o r i n d i v i d u a l ba c o m p r o m i s e d t h e i n t e r p r e u r e s i n p a s t SDT i n v e s t i g ds t h i s p r o b l e m s i n c e a l l t i m u l u s l e v e l s and a l l of r e l a t i v e t o t h e same c u t t i c n o t f o u n d i n p r e v i o u s H o w s f o r t h e unambiguous i n d' and b e t a . T h u s , t h i f f e r e n c e s i n t h e d* meas t i o n of t h e s e n s o r y s e n s i t o r a d i a n t h e a t s t i m u l i 108 p a t i e n t s w i t h a c l e a r o r g a n i c b a s i s f o r t h e i r c o n d i t i o n . The h y p e r v i g i 1 a n c e model was h y p o t h e s i z e d t o be r e f l e c t e d by a low p a i n t h r e s h o l d and a l o w e r c r i t e r i o n t o r e p o r t s e n s a t i o n s as p a i n f u l r e l a t i v e t o p a i n - f r e e i n d i v i d u a l s . A l t h o u g h the p a t t e r n of r e s u l t s i s c o n s i s t e n t w i t h t h i s p r e d i c t i o n between p a t i e n t s w i t h o u t c l e a r o r g a n i c d i a g n o s e s and t h e n o r m a l c o n t r o l s a m p l e , t h e d i f f e r e n c e s were no t s t a t i s t i c a l l y s i g n i f i c a n t . The i m p l i c a t i o n s o f t h e s e f i n d i n g s and a d i s c u s s i o n of t h e s i g n i f i c a n c e of t h e e v a l u a t i o n of m e d i c a l l y i n c o n g r u e n t s y m p t o m a t o l o g y w i l l be a d d r e s s e d below. M e d i c a l l y I n c o n g r u e n t Symptom P r e s e n t a t i o n , D i s a b i l i t y , and P s y c h o l o g i c a l D i s t r e s s The c l a s s i f i c a t i o n o f p a i n p a t i e n t s i n t o t h o s e w i t h and w i t h o u t m e d i c a l l y i n c o n g r u e n t s i g n s r e s u l t e d i n s i g n i f i c a n t g r o u p d i f f e r e n c e s on t h e i r s u b j e c t i v e r e p o r t o f d i s a b i l i t y o n l y . T h i s r e s u l t i s s i m i l a r t o t h a t r e p o r t e d by R e e s o r & C r a i g ( 1 9 8 8 ) . They a l s o r e p o r t e d c l e a r g r o u p d i f f e r e n c e s on a measure of o b j e c t i v e s t r u c t u r a l l i m i t a t i o n s o r p h y s i c a l i m p a i r m e n t . The f i n d i n g of no g r o u p d i f f e r e n c e s on o b j e c t i v e p h y s i c a l i m p a i r m e n t i n t h i s s t u d y may be due t o t h e s i g n i f i c a n t p e r c e n t a g e o f m i s s i n g d a t a ( i . e . , 5 4 % ) . I n a d d i t i o n , R e e s o r & C r a i g f o u n d s i g n i f i c a n t g r o u p d i f f e r e n c e s on c o g n i t i v e m e a s u r e s a f t e r p a r t i a l l y out t h e v a r i a n c e due t o o b j e c t i v e p h y s i c a l i m p a i r m e n t . P a t i e n t s w i t h a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n were f o u n d t o engage i n more m a l a d a p t i v e c o g n i t i o n s ( i . e . , c a t a s t r o p h i z i n g ) , i n e f f e c t i ve 109 c o p i n g s t r a t e g i e s ( e . g . , p r a y i n g and h o p i n g ) , and t o r e p o r t a l o w e r s e n s e of. s e l f - e f f i c a c y t o c o n t r o l t h e p a i n r e l a t i v e to p a t i e n t s who d i d n o t d i s p l a y i n c o n g r u e n t symptoms ( R e e s o r & C r a i g , 1 9 8 8 ) . A l t h o u g h s t a t i s t i c a l s i g n i f i c a n c e was n o t r e a c h e d i n t h e p r e s e n t s t u d y on m e a s u r e s of c o p i n g and p a i n - r e l a t e d c o g n i t i o n s , t h e d i r e c t i o n of g r o u p d i f f e r e n c e s was c o n s i s t e n t w i t h R e e s o r & C r a i g . P a t i e n t s w i t h m e d i c a l l y i n c o n g r u e n t symptoms t e n d e d t o c a t a s t r o p h i z e more a b o u t t h e p a i n , r e p o r t e d l e s s e f f i c a c y t o c o n t r o l t h e p a i n , and were more i n c l i n e d t o use p a s s i v e c o p i n g s t r a t e g i e s ( i . e . , p r a y i n g and h o p i n g ) . The l a c k o f s i g n i f i c a n t f i n d i n g s on c o g n i t i v e m e a s u r e s i n t h e p r e s e n t s t u d y may be a t t r i b u t a b l e t o t h e s m a l l e r number of s u b j e c t s t e s t e d p e r g r o u p . R e e s o r & C r a i g a s s e s s e d f o r t y p a i n p a t i e n t s i n e a c h g r o u p i n c o n t r a s t t o t h e t h i r t y t e s t e d i n t h e p r e s e n t s t u d y . However, a power a n a l y s i s b a s e d on t h e i r f i n d i n g s r e v e a l e d t h a t enough power s h o u l d have been a c h i e v e d w i t h t h i r t y s u b j e c t s i n e a c h g r o u p (power e s t i m a t e d a t . 9 4 ) . O t h e r p o s s i b l e r e a s o n s f o r t h e l a c k of s i g n i f i c a n t g r o u p d i f f e r e n c e s may be t h a t s l i g h t l y d i f f e r e n t p a i n p o p u l a t i o n s were a s s e s s e d . No c o m p e n s a t i o n / l i t i g a t i o n p a t i e n t s were a s s e s s e d i n t h e p r e s e n t s t u d y and many p a t i e n t s who v o l u n t e e r e d were n o t t a k i n g r e g u l a r m e d i c a t i o n f o r t h e i r p a i n p r o b l e m , u n l i k e R e e s o r & C r a i g ' s s a m p l e . T h i s may have r e s u l t e d i n t h e s e l e c t i o n of a sample of p a t i e n t s who were more s e l f - r e l i a n t on e f f e c t i v e c o p i n g s t r a t e g i e s and t h u s , were l e s s l i k e l v t o c a t a s t r o p h i z e o r t o depend on p a s s i v e 110 c o p i n g s t r a t e g i e s l i k e p r a y i n g and h o p i n g . The f i n d i n g t h a t t h e m e a s u r e s o f i n c o n g r u e n t p a i n p r i m a r i l y d i s t i n g u i s h e d p a t i e n t s on s e l f - p e r c e i v e d d i s a b i l i t y i s s u p p o r t e d by p a s t r e s e a r c h . M e a s u r e s o f i n c o n g r u e n t p a i n p r e s e n t a t i o n ( n o n o r g a n i c p h y s i c a l s i g n s , i n a p p r o p r i a t e symptoms, and t h e p a i n d r a w i n g ) have been f o u n d t o be m o s t l y p r e d i c t i v e of t h e p a t i e n t s ' r e p o r t of d i s a b i l i t y and t o a l e s s e r d e g r e e , p h y s i c a l i m p a i r m e n t ( M a i n & W a d d e l i , 1984; W a d d e l i e t a l . , 1 9 8 9 ) . A s m a l l and m a r g i n a l l y s t a t i s t i c a l l y i n s i g n i f i c a n t c o r r e l a t i o n was f o u n d between d i s a b i l i t y and p h y s i c a l i m p a i r m e n t i n t h e p r e s e n t i n v e s t i g a t i o n (_r=.27, p_= .08, n = 2 7 ) . The same d e g r e e of a s s o c i a t i o n was r e p o r t e d by M a i n & W a d d e l i ( 1 9 8 4 ) ; however, w i t h t h e i r sample of 200 p a t i e n t s , t h e r e s u l t was f o u n d t o be s i g n i f i c a n t . The r e l a t i o n s h i p between the d e g r e e of p h y s i c a l i m p a i r m e n t and m e a s u r e s of m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n i s not c l e a r i n p a s t r e s e a r c h . A l t h o u g h R e e s o r f o u n d low but s i g n i f i c a n t c o r r e l a t i o n s between p h y s i c a l i m p a i r m e n t and b o t h t h e s e l f r e p o r t of i n a p p r o p r i a t e symptoms and t h e p a i n d r a w i n g , th e r e s u l t s o f t h e p r e s e n t s t u d y r e v e a l e d o n l y a low c o r r e l a t i o n between i m p a i r m e n t and the s e l f r e p o r t o f i n a p p r o p r i a t e symptoms. F u r t h e r , p h y s i c a l i m p a i r m e n t was f o u n d t o have a low c o r r e l a t i o n w i t h p a s s i v e s t y l e s o f c o g n i t i v e c o p i n g s t r a t e g i e s and t o 'worry' about th e p a i n c o n d i t i o n but was n o t s i g n i f i c a n t l y a s s o c i a t e d w i t h any of t h e o t h e r c o g n i t i v e o r a f f e c t i v e v a r i a b l e s i n t h e p r e s e n t s t u d y . W a d d e l i & M a i n (1984) f o u n d t h a t "most of t h e 111 p s y c h o m e t r i c v a r i a b l e s c o r r e l a t e s i g n i f i c a n t l y w i t h i n a p p r o p r i a t e s i g n s , i n a p p r o p r i a t e symptoms, and d i s a b i l i t y , but h a r d l y a t a l l w i t h th e d e g r e e o f p h y s i c a l i m p a i r m e n t . " ( p . 3 2 ) . A d d i t i o n a l l y t h e y d i d n o t f i n d a s i g n i f i c a n t a s s o c i a t i o n b etween the p a i n d r a w i n g and p h y s i c a l i m p a i r m e n t , u n l i k e R e e s o r & C r a i g ( 1 9 8 8 ) . U s i n g th e same d a t a f r o m W a d d e l l & M a i n ' s (1984) s t u d y , however, W a d d e l l e t a l . (1989) d i v i d e d p a t i e n t s i n t o two g r o u p s on t h e b a s i s of t h e sum o f i n a p p r o p r i a t e s i g n s and symptoms. P a t i e n t s who had l e s s t h a n two i n a p p r o p r i a t e s i g n s and symptoms were f o u n d t o be l e s s p h y s i c a l l y i m p a i r e d t h a n p a t i e n t s who had more t h a n f i v e i n a p p r o p r i a t e s i g n s and symptoms. T h u s , the r e l a t i o n s h i p b etween o b j e c t i v e s t r u c t u r a l l i m i t a t i o n s and m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms i s n o t e n t i r e l y c l e a r . B e c a u s e t h e r e may be a s y s t e m a t i c r e l a t i o n s h i p , however, i t s h o u l d be a s s e s s e d w i t h a view t o c o v a r y i n g i t out of t h e a n a l y s e s of p s y c h o l o g i c a l f a c t o r s i f a p p r o p r i a t e . P h y s i c a l i m p a i r m e n t and s u b j e c t i v e d i s a b i l i t y a p p e a r t o a s s e s s d i f f e r e n t a s p e c t s of a c h r o n i c p a i n c o n d i t i o n . In t h e p r e s e n t s t u d y , p h y s i c a l i m p a i r m e n t was p r i m a r i l y a s s o c i a t e d w i t h w o r r y a b o u t the p a i n w h i c h r e f l e c t s l o n g term c o n c e r n s ( e . g . , " I w o r r y a b o u t my f a m i l y " ; " I wonder how l o n g t h i s w i l l l a s t " ) . In c o n t r a s t , d i s a b i l i t y was a s s o c i a t e d w i t h c a t a s t r o p h i z i n g c o g n i t i o n s and h e i g h t e n e d e m o t i o n a l i t y ( i . e . , f e e l i n g s of f r u s t r a t i o n , d e p r e s s i o n , a n g e r , a n x i e t y , and s e l f - p i t y ) . O t h e r i n v e s t i g a t o r s have r e p o r t e d a l i n k between s e l f - r e p o r t of d i s a b i l i t y and d e p r e s s i o n ( m a n i f e s t e d m a i n l y as 112 f r u s t r a t i o n and a n g e r ) , i n c r e a s e d s o m a t i c v i g i l a n c e , a b normal p a i n d r a w i n g s , m i s t r u s t of h e a l t h c a r e p r o f e s s i o n a l s , n a i v e schemas r e g a r d i n g p a i n , i n c r e a s e d m e d i c a t i o n u s e , and c o n t i n u o u s p a i n r e p o r t s of h i g h i n t e n s i t y ( B a r n e s e t a l . , 1989; L e a v i t t , 1990; Lee et a l . , 1989; Greenough & F r a s e r , 1989; P o l a t i n e t a l . , 1989; G a l l o n , 1989; L a c r o i x e t a l . , 1990; B i g o s et a l . , 1991). W a d d e l i e t a l . , (1989) c o n s i d e r m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms ( o r m a g n i f i e d i l l n e s s b e h a v i o u r ) to be a form of c o m m u n i c a t i o n between the p a t i e n t and the p h y s i c i a n . They a r e e s s e n t i a l l y a more e m p h a t i c e x p r e s s i o n of the l e v e l of d i s e a s e s e v e r i t y w h i c h i s a r e f l e c t i o n of, t h e p a t i e n t s ' d i s t r e s s about the p r o b l e m . Measures of m a g n i f i e d i l l n e s s b e h a v i o u r a r e s a i d t o be p r i m a r i l y a s s o c i a t e d t o d i s a b i l i t y and s e c o n d a r i l y to p s y c h o l o g i c a l d i s t r e s s ( W a d d e l i e t a l . , 1989). T h i s was s u p p o r t e d by the p r e s e n t s t u d y a s , a l t h o u g h the a s s e s s m e n t of m e d i c a l l y i n c o n g r u e n t symptoms p r i m a r i l y d i s t i n g u i s h e d p a t i e n t s ' on s e l f p e r c e i v e d d i s a b i l i t y , e a ch s e p a r a t e measure ( i . e . , the p a i n d r a w i n g , n o n o r g a n i c p h y s i c a l s i g n s , and i n a p p r o p r i a t e symptoms) was a l s o f o u n d t o be a s s o c i a t e d w i t h measures of p s y c h o l o g i c a l d i s t r e s s . The p a i n d r a w i n g was f o u n d t o have a c o n s i s t e n t a s s o c i a t i o n t o a f f e c t i v e d i s t r e s s ( t r a i t a n x i e t y , w o r r y and e m o t i o n a l i t y about, the p a i n , and c a t a s t r o p h i c c o g n i t i o n s ) i n the p r e s e n t s t u d y . T h i s r e s u l t s u p p o r t s the f i n d i n g s of p r e v i o u s i n v e s t i g a t i o n s w h i c h r e p o r t a r e l a t i o n s h i p between abnormal p a i n d r a w i n g s and t h e h y s t e r i a and h y p o c h o n d r i a s i s s c a l e s of 113 t h e MMPI ( D z i o b a & Doxey, 1984; Murphy & C o r n i s h , 1984; R a n s f o r d e t a l - , 1976; and T a y l o r e t a l . , 1 9 8 4 ) . In a d d i t i o n , t h e p a i n d r a w i n g has been f o u n d t o be p r e d i c t i v e of a p oor r e s p o n s e t o t r e a t m e n t ( P o l a t i n e t a l . , 1989; Uden e t a l . , 1 9 8 8 ) . The n o n o r g a n i c p h y s i c a l s i g n s were f o u n d t o r e f l e c t t h e use of v a r i o u s c o p i n g s t r a t e g i e s ( p r a y i n g , h o p i n g , d i v e r t i n g a t t e n t i o n , r e i n t e r p r e t i n g p a i n s e n s a t i o n s , c o p i n g s e l f - s t a t e m e n t s , and i g n o r i n g t h e p a i n ) , but a l s o t o a t e n d e n c y to c a t a s t r o p h i z e a b o u t t h e p a i n . L a c r o i x e t a l . ( 1 9 9 0 ) r e p o r t e d t h a t t h e n o n o r g a n i c p h y s i c a l s i g n s were r e l a t e d t o l o w e r e d u c a t i o n and n a i v e schemas r e g a r d i n g p a i n and t h e y s u g g e s t e d t h a t t h e p h y s i c a l s i g n s may r e f l e c t t h e b e h a v i o u r a l c o n s e q u e n c e s o f p o o r u n d e r s t a n d i n g o f t h e i r c o n d i t i o n . M a i n & W a d d e l l (1984) r e p o r t e d t h a t t h e n o n o r g a n i c p h y s i c a l s i g n s and i n a p p r o p r i a t e symptoms were r e l a t e d t o d e p r e s s e d mood and h e i g h t e n e d s o m a t i c a w a r e n e s s . I n a p p r o p r i a t e symptoms were a s s o c i a t e d w i t h p a s s i v e c o p i n g s t r a t e g i e s ( i . e . , p r a y i n g , h o p i n g , and d i v e r t i n g a t t e n t i o n ) , a low s e n s e of e f f i c a c y t o c o n t r o l p a i n , and c a t a s t r o p h i c c o g n i t i o n s i n t h e p r e s e n t s t u d y . T h u s , i t i s r e a s o n a b l e t o c o n s i d e r m e a s u r e s of i n c o n g r u e n t p a i n p r e s e n t a t i o n as a s s e s s m e n t s o f t h e p a t i e n t ' s p e r c e p t i o n and e x p r e s s i o n of d i s a b i l i t y w h i c h i s r e f l e c t i v e of h i s / h e r c o n c e r n and d i s t r e s s a b o u t t h e p r o b l e m . The p a t i e n t g r o u p s i d e n t i f i e d as ' o r g a n i c ' and ' f u n c t i o n a l ' i n t h e p r e s e n t s t u d y were n o t d i s t i n g u i s h e d on t h e m e a s u r e s of i n c o n g r u e n t p a i n p r e s e n t a t i o n or on any of t h e 114 c o g n i t i v e o r a f f e c t i v e m e a s u r e s . T h i s f i n d i n g i s s i m i l a r to t h a t r e p o r t e d i n p r e v i o u s r e s e a r c h ( F l o r & T u r k , 1987; L e a v i t t & G a r r o n , 1 9 7 9 ) . W a d d e l i e t a l . (1980) f o u n d no s i g n i f i c a n t c o r r e l a t i o n between t h e p r e s e n c e of n o n o r g a n i c s i g n s and c l e a r o r g a n i c e t i o l o g y a l t h o u g h t h e n o n o r g a n i c s i g n s were l e s s common i n c a s e s w i t h o b v i o u s p a t h o p h y s i o 1 o 1 o g y . Doxey e t a l . ( 1 9 8 8 ) r e p o r t e d t h a t p a t i e n t s w i t h u n c l e a r p h y s i c a l p a t h o l o g y may n o t n e c e s s a r i l y p r e s e n t w i t h more p s y c h o l o g i c a l d i s t r e s s but t h a t p s y c h o l o g i c a l d i s t r e s s , i f p r e s e n t , may p l a y an i m p o r t a n t r o l e i n t h e m a i n t e n a n c e o f d i s a b i l i t y i n t h a t g r o u p . The c o r r e l a t i o n a l n a t u r e of t h i s s t u d y p r e v e n t s c a u s a l i n t e r p r e t a t i o n s o f t h e d a t a , however, r e l a t i o n s h i p s among v a r i a b l e s l e a d t o s p e c u l a t i o n s as t o the n a t u r e of t h o s e r e l a t i o n s h i p s . The f i n d i n g s o f t h i s s t u d y i n c o n j u n c t i o n w i t h p a s t r e s e a r c h s u g g e s t s t h a t t h e p r e s e n c e o r a b s e n c e of a c l e a r o r g a n i c d i a g n o s i s may r e s u l t i n a l t e r a t i o n s i n how p a i n i s p e r c e i v e d and r e p o r t e d . In c o n t r a s t , t h e p r e s e n t a t i o n of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms ( w h i c h a p p e a r t o be i n d e p e n d e n t of t h e p h y s i c a l s t a t u s of t h e p a t i e n t ) a r e r e f l e c t i o n s o f t h e p a t i e n t s c o n c e r n and d i s t r e s s r e g a r d i n g h i s / h e r p a i n and d i s a b i l i t y . The h y p e r v i g i 1 a n c e model r e f e r s t o an a l t e r a t i o n i n p a i n p e r c e p t i o n due t o a s h i f t i n a t t e n t i o n t o s i g n s of s o m a t i c d i s t r e s s (Chapman, 1986). The a b s e n c e o f a c l e a r o r g a n i c d i a g n o s i s may be more l i k e l y t o l e a d t o i n c r e a s e d s o m a t i c v i g i l a n c e , p a r t i c u l a r l y i f t h e p a t i e n t has a n a i v e schema a b o u t t h e p a i n ( i . e . , t h a t i t i s e i t h e r p h y s i c a l o r p s y c h o l o g i c a l ) and i s d e t e r m i n e d t o f i n d p h y s i c a l p a t h o l o g y . P s y c h o l o g d e p r e s s i o n , p oor c o p i n g s k i l l s r e s u l t i n i n c r e a s e d s o m a t i c v i r e l a t e d t o how t h e p a i n and d i i n d i v i d u a l ' s d a i l y l i f e r a t h e r c a u s e o f t h e p a i n . In t h e abs v i g i l a n c e , j u d g e m e n t s of p a i n p r i n c i p l e s o f t h e a d a p t a t i o n - 1 i c a l f a c t o r s ( i . e . , a n x i e t y , e t c . ) may n o t n e c e s s a r i l y g i l a n c e s i n c e t h e y may be s a b i l i t y a r e a f f e c t i n g t h e t h a n e s t a b l i s h i n g t h e s p e c i f i c e nce o f i n c r e a s e d s o m a t i c a p p e a r t o be b a s e d on t h e eve 1 m o d e l . The r o l e o f c o g n i t i o n and e m o t i o n i n t h e e x p e r i e n c e o f p a i n . I t i s o f i n t e r e s t t h a t e s s e n t i a l l y no r e l a t i o n s h i p between m e a s u r e s of p a i n r e l a t e d c o g n i t i o n s and the SDT m e a s u r e s o f p a i n p e r c e p t i o n was f o u n d . T h a t i s , i t a p p e a r s t h a t p a i n r e l a t e d c o g n i t i o n s and a n x i e t y a r e u n r e l a t e d t o t h e r e s p o n s e b i a s t o r e p o r t p a i n o r t o d i s c r i m i n a b i 1 i t y ( i . e . , s e n s i t i v i t y to p a i n f u l s t i m u l i ) . I t s h o u l d be n o t e d , however t h a t t h e m e a s u r e s of p a i n r e l a t e d c o g n i t i o n s and a n x i e t y were r e l e v a n t t o t h e p a t i e n t ' s c l i n i c a l c o n d i t i o n and may s i m p l y n o t be r e l a t e d t o a t a s k i n v o l v i n g l a b o r a t o r y i n d u c e d p a i n . As w e l l , t h e measure of p a i n u s e d h e r e c o n c e r n e d p a i n t h r e s h o l d r a t h e r t h a n t h e s u p r a - t h r e s h o 1 d l e v e l s o f p a i n t h e p a t i e n t s must manage. More i n t e r e s t i n g i s t h e p r e s e n c e of an a s s o c i a t i o n between m e a s u r e s of p a i n r e l a t e d w o r r y , e m o t i o n a l i t y , and c a t a s t r o p h i z i n g and t h e s u b j e c t i v e r a t i n g s of the s e n s o r y i n t e n s i t y of p a i n . T h o s e p a t i e n t s who r e p o r t e d h i g h e r l e v e l s of a f f e c t i v e d i s t r e s s a b o u t t h e i r p a i n c o n d i t i o n a l s o r a t e d t h e p a i n f u l s t i m u l i as s u b j e c t i v e l y more i n t e n s e . T h i s f i n d i n g i s s i m i l a r t o t h a t r e p o r t e d i n t h e p a s t where c a t a s t r o p h i c c o g n i t i o n s and p e r c e i v e d h e l p l e s s n e s s t o c o n t r o l p a i n have been a s s o c i a t e d w i t h h i g h e r r a t i n g s of s e n s o r y i n t e n s i t y o f p a i n , i n c r e a s e d f u n c t i o n a l d i s a b i l i t y , i n c r e a s e d p a i n r e p o r t , and d e c r e a s e d p a i n t o l e r a n c e ( B a n d u r a , 1987; F l o r & T u r k , 1987; Hal s a m , 1966; H i l l e t a l . , 1952; K e e f e e t a l . , 1989; L e p a n t o e t a l . , 1965; M e n d l e r & Watson, 1966; R e e s o r & C r a i g , 1988; S p i n h o v e n e t a l . , 1989; S z p i l e r 6. E p s t e i n , 1 9 7 6 ) . I t a p p e a r s , t h e r e f o r e , t h a t w h i l e c o g n i t i v e and a f f e c t i v e f a c t o r s a r e a s s o c i a t e d w i t h t h e s u b j e c t i v e e x p e r i e n c e of p a i n , t h e y a r e n o t n e c e s s a r i l y a s s o c i a t e d w i t h g e n e r a l p a i n s e n s i t i v i t y o r t h e r e s p o n s e b i a s t o r e p o r t p a i n . T h i s may a c c o u n t f o r t h e f i n d i n g s t h a t c o g n i t i v e - b e h a v i o u r a 1 programs f o r p a i n management r e s u l t i n i m p r o v e d mood, i n c r e a s e d c o p i n g , d e c r e a s e d m e d i c a t i o n u s e , and l e s s f u n c t i o n a l d i s a b i l i t y d e s p i t e no c l e a r improvement i n p a i n i t s e l f ( S k i n n e r e t a l . , 19 9 0 ) . G e nder D i f f e r e n c e s i n t h e E x p e r i e n c e and E x p r e s s i o n o f P a i n The r e s u l t s o f t h e p r e s e n t s t u d y showed no o v e r a l l g e n d e r d i f f e r e n c e s f o r p a i n t h r e s h o l d o r the c r i t e r i o n to r e p o r t p a i n . However, w i t h i n t h e c h r o n i c p a i n g r o u p , women were b e t t e r a b l e t o d i s c r i m i n a t e between h e a t and f a i n t p a i n t h a n men s u g g e s t i n g t h a t t h e y were more s e n s i t i v e t o t h e s t i m u l i . In a d d i t i o n , women g e n e r a l l y r a t e d t h e p a i n s t i m u l i as more 117 i n t e n s e and u n p l e a s a n t t h a n men. F i n a l l y , ot i n t e r e s t i n the p r e s e n t s t u d y , i s t h e s i g n i f i c a n t g r o u p by sex i n t e r a c t i o n f o r th e i n c l i n a t i o n t o r e p o r t p a i n f u l s e n s a t i o n s . W i t h i n t h e n o r m a l c o n t r o l g r o u p , men were l e s s i n c l i n e d t o r e p o r t p a i n f u l s e n s a t i o n s t h a n women but w i t h i n t h e c h r o n i c p a i n g r o u p s , men were more i n c l i n e d t o r e p o r t p a i n f u l s e n s a t i o n s t h a n women. None o f t h e p r e v i o u s SDT i n v e s t i g a t i o n s of c h r o n i c p a i n p o p u l a t i o n s have e v a l u a t e d sex d i f f e r e n c e s . R e s e a r c h e v a l u a t i n g sex d i f f e r e n c e s i n p a i n p e r c e p t i o n i n t h e p a s t has been i n c o n s i s t e n t , w i t h some i n v e s t i g a t o r s r e p o r t i n g no g e n d e r d i f f e r e n c e s f o r p a i n t h r e s h o l d and t o l e r a n c e l e v e l s ( C l a r k & M e h l , 1971; C l a u s e n & K i n g , 1950; Har d y , W o l f f , & G o o d e l l , 1952; Notermans & T o p h o o f f , 1967; and Sherman & R o b i l l a r d , 1967) and o t h e r s r e p o r t i n g women t o have l o w e r p a i n t h r e s h o l d s and t o l e r a n c e l e v e l s t h a n men (Brennem e t a l . , 1989; H a l l & S t r i d e , 19 5 4; R o l l m a n , 6. H a r r i s , 1987 ; S t e v e n s , 1 9 6 7 ) . A r c h e r (1976) r e p o r t e d t h a t f e m a l e s were f o u n d t o have l o w e r t h r e s h o l d s f o r many s e n s o r y m o d a l i t i e s i n c l u d i n g t o u c h , p a i n , h e a r i n g , t a s t e , s m e l l , and r o d v i s i o n . R o l l m a n & H a r r i s (1987) n o t e d t h a t a l t h o u g h t h e r e a r e some i n c o n s i s t e n c i e s i n t h e r e s e a r c h on g e n d e r d i f f e r e n c e s i n p a i n p e r c e p t i o n , most of t h e d a t a i n d i c a t e s a sex d i f f e r e n c e i n t h e d i r e c t i o n of f e m a l e s h a v i n g l o w e r t h r e s h o l d s and t o l e r a n c e l e v e l s t h a n men f o r h e a t , e l e c t r i c s h o c k , and m e c h a n i c a l p r e s s u r e p a i n . A d d i t i o n a l l y , t h e y f o u n d t h a t f e m a l e s r a t e d e l e c t r i c s h o c k as s u b j e c t i v e l y more p a i n f u l t h a n m a l e s . R o l l m a n & H a r r i s ( 1 9 8 7 ) , however, i n d i c a t e d t h a t i t r e m a i n s 118 u n c l e a r t o what e x t e n t s e n s o r y and n o n s e n s o r y t a c t o r : c o n t r i b u t e t o t h e r e p o r t e d sex d i t t e r e n c e s i n p a i n p e r c e p t i o n . The r e s u l t s ot t h e p r e s e n t i n v e s t i g a t i o n s u g g e s t t h a t t h e r e l a t i o n s h i p between g e n d e r , c h r o n i c p a i n , and p a i n p e r c e p t i o n i s c o m p l e x and more r e s e a r c h i s needed t o c l a r i f y t h e r e s u l t s . S i g n i f i c a n t g e n d e r d i f f e r e n c e s were f o u n d i n t h i s s t u d y f o r t h e s e l f r e p o r t o f d i s a b i l i t y , w i t h women r e p o r t i n g more f u n c t i o n a l d i s a b i l i t y t h a n men. T h a t women t e n d to be more o u t s p o k e n a b o u t t h e i r d i s c o m f o r t and d i s a b i l i t y has been s u p p o r t e d by o t h e r r e s e a r c h ( L e e e t a l . , 1 9 8 9 ) . The g r e a t e r t e n d e n c y t o w a r d s e l f d i s c l o s u r e i n women may a c c o u n t f o r the o b s e r v e d t r e n d s d i f f e r e n t i a t i n g g e n d e r f o r t h e r e p o r t e d use of c o p i n g s t r a t e g i e s . Women were f o u n d t o r e p o r t u s i n g p a s s i v e c o g n i t i v e co.ping s t r a t e g i e s ( i . e . , p r a y i n g , h o p i n g , and d i v e r t i n g a t t e n t i o n t o o t h e r m a t t e r s ) and b e h a v i o u r a l c o p i n g s t r a t e g i e s more o f t e n t h a n men. In a d d i t i o n , women r e p o r t e d a g r e a t e r s e n s e of s e l f - e f f i c a c y t o manage t h e p a i n t h a n men. T h e r e was no a p p a r e n t t r e n d f o r sex d i f f e r e n c e s i n t h e t e n d e n c y t o c a t a s t r o p h i z e . B e c a u s e t h e s e f i n d i n g s a r e t r e n d s o n l y , l i t t l e c r e d e n c e may be g i v e n them. However, t h e y a r e s u g g e s t i v e o f o v e r a l l sex d i f f e r e n c e s i n t h e e x p r e s s i o n and e x p e r i e n c e of p a i n and d i s a b i l i t y . Summary and C o n c l u s i o n s The p u r p o s e of t h i s i n v e s t i g a t i o n was t o e v a l u a t e t h e s u p p o s i t i o n t h a t p a i n p e r c e p t i o n i s a l t e r e d i n c h r o n i c p a i p a t i e n t s . Two models were p r e s e n t e d w h i c h y i e l d o p p o s i n g p r e d i c t i o n s r e g a r d i n g how t h e p e r c e p t i o n of p a i n i s a l t e r e The h v p e r v i g i l a n c e model l e d t o t h e p r e d i c t i o n t h a t c h r o n i p a i n p a t i e n t s w o u l d have l o w e r p a i n t h r e s h o l d s and would b more l i k e l y t o r e p o r t s i g n s o f s o m a t i c d i s t r e s s t h a n p a i n - i n d i v i d u a l s b e c a u s e of i n c r e a s e d s o m a t i c v i g i l a n c e (Chapma 1 9 8 6 ) . The a d a p t a t i o n - 1 e v e 1 l o d e l , i n c o n t r a s t , l e d t o t h p r e d i c t i o n t h a t c h r o n i c p a i n p a t i e n t s would have h i g h e r pa t h r e s h o l d s and would be l e s s l i k e l y t o l a b e l s o m a t i c s e n s a t i o n s as p a i n f u l t h a n p a i n - f r e e i n d i v i d u a l s . T h i s i s b e c a u s e , r e l a t i v e t o t h e i r i n t e r n a l d i s c o m f o r t , a d d i t i o n a l p a i n f u l s t i m u l i w ould be j u d g e d as i n n o c u o u s ( R o l l m a n , 1 979). B o t h m o dels had r e c e i v e d s u p p o r t i n p a s t r e s e a r c h but b e c a u s e of m e t h o d o l o g i c a l i n c o n s i s t e n c i e s , i t was u n c l e a r u n d e r w h i c h c o n d i t i o n s p a i n p a t i e n t s w o u l d be o v e r - or u n d e r r e s p o n s i v e t o p a i n f u l s t i m u l i . The p r e s e n t s t u d y was d e s i g n e d t o examine u n d e r what c i r c u m s t a n c e s t h e p r e d i c t i o n s o f e a c h model a r e met. The r e s u l t s of t h i s i n v e s t i g a t i o n r e v e a l e d t h a t p a t i e n t s w i t h c l e a r p h y s i c a l p a t h o l o g y had h i g h e r p a i n t h r e s h o l d s t h a n p a i n - f r e e i n d i v i d u a l s w h i c h was p r i m a r i l y r e p r e s e n t e d by a h i g h e r c r i t e r i o n by w h i c h t o r e p o r t s e n s a t i o n s as p a i n f u l . The r e s p o n s e s of t h e s e p a t i e n t s c o n f o r m e d t o t h e p r e d i c t i o n . o f t h e a d a p t a t i o n - 1 e v e 1 m o d e l . P a t i e n t s w i t h u n c l e a r p h y s i c a l 120 p a t h o l o g y , however, were f o u n d to have s i g n i f i c a n t l y l o w e r p a i n t h r e s h o l d s and were more i n c l i n e d t o l a b e l s e n s a t i o n s as p a i n f u l r e l a t i v e t o ' o r g a n i c ' p a i n p a t i e n t s but were not s i g n i f i c a n t l y d i f f e r e n t i n t h e i r r e s p o n s e s t o t h e n o r m a l c o n t r o l s a m p l e . T h u s , t h e p r e d i c t i o n of t h e h y p e r v i g i 1 a n c e model was n o t s u p p o r t e d i n t h i s s t u d y . I t s h o u l d be n o t e d , however, t h a t t h i s f i n d i n g may be p a r t i a l l y d e p e n d e n t upon the t y p e o f p a i n s t i m u l u s u s e d i n t h i s s t u d y ( i . e . , a p h a s i c p a i n s t i m u l u s ) . The f i n d i n g s o f t h i s s t u d y d i f f e r e n t i a t e d p a i n p a t i e n t s i n t h e i r r e s p o n s e s t o p a i n f u l s t i m u l i s u g g e s t i n g t h a t p a i n p e r c e p t i o n may be a l t e r e d i n c h r o n i c p a i n p a t i e n t s . However, r a t h e r t h a n a change i n s e n s i t i v i t y t o p a i n f u l s t i m u l i , d i f f e r e n c e s i n p a i n t h r e s h o l d were f o u n d t o be p r i m a r i l y r e f l e c t i v e o f t h e r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s as p a i n f u l . I t i s p o s s i b l e t h a t t h e a b s e n c e o f an o r g a n i c e x p l a n a t i o n f o r t h e p a i n l e a d s p e o p l e t o s h i f t t h e i r a t t e n t i o n a l f o c u s t o s i g n s of s o m a t i c d i s t r e s s i n an e f f o r t t o i d e n t i f y a p h y s i c a l c a u s e . T h i s a t t e n t i o n a l s h i f t may r e s u l t i n t h e o v e r r i d i n g o f t h e use o f an a d a p t a t i o n - 1 e v e 1 i n t h e judgement of p e r c e p t u a l s t i m u l i . T h a t i s , a l t h o u g h t h e y may have a h i g h e r a d a p t a t i o n - 1 e v e 1 f r o m w h i c h t o judge p a i n f u l s t i m u l i , t h e i r i n t e n s e f o c u s on s o m a t i c d i s t r e s s r e s u l t s i n i n c r e a s e d p a i n r e p o r t . The use o f a t o n i c p a i n s t i m u l u s w h i c h may e n g e n d e r g r e a t e r d i s t r e s s i n v u l n e r a b l e p a t i e n t s may have y i e l d e d s t a t i s t i c a l s u p p o r t f o r t h e h y p e r v i g i 1 ance model as has been f o u n d i n p r e v i o u s r e s e a r c h . The p r e s e n c e of a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n and p s y c h o l o g i c a l v a r i a b l e s ( c o g n i t i o n s , p a i n c o p i n g s t r a t e g i e s , and d i s t r e s s ) d i d n o t d i s t i n g u i s h p a i n p a t i e n t s on p a i n p e r c e p t i o n m e a s u r e s c o n t r a r y t o t h e h y p o t h e s e s . In f a c t , p s y c h o l o g i c a l v a r i a b l e s were m o s t l y u n r e l a t e d t o p a i n r e s p o n s e ( i . e . , t h r e s h o l d , d i s c r i m i n a b i 1 i t y , and r e s p o n s e b i a s ) w i t h t h e e x c e p t i o n t h a t w o r r y , h e i g h t e n e d e m o t i o n a l i t y , and c a t a s t r o p h i z i n g c o g n i t i o n s were r e l a t e d t o h i g h e r r a t i n g s of t h e s e n s o r y i n t e n s i t y of t h e p a i n f u l s t i m u l i . R a t h e r , p a t i e n t s w i t h m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms were f o u n d t o r e p o r t g r e a t e r f u n c t i o n a l d i s a b i l i t y t h a n t h o s e w i t h o u t i n c o n g r u e n t symptoms. In a d d i t i o n , a l t h o u g h n o t s t a t i s t i c a l l y s i g n i f i c a n t , t h e y t e n d e d t o c a t a s t r o p h i z e more ab o u t th e p a i n , t o r e p o r t l e s s e f f i c a c y t o c o n t r o l t h e p a i n , and t o be more i n c l i n e d t o use p a s s i v e c o p i n g s t r a t e g i e s s u c h as p r a y i n g and h o p i n g . F i n a l l y , t h e m e a s u r e s of m e d i c a l l y i n c o n g r u e n t symptoms were f o u n d t o be a s s o c i a t e d w i t h m e asures of e m o t i o n a l d i s t r e s s r e g a r d i n g t h e p a t i e n t s ' p a i n p r o b l e m s . In c o n j u n c t i o n w i t h p a s t r e s e a r c h w h i c h s u p p o r t s t h e s e f i n d i n g s , t h e c a t e g o r i z a t i o n of p a i n p a t i e n t s i n t o t h o s e w i t h and w i t h o u t a m e d i c a l l y i n c o n g r u e n t p a i n p r e s e n t a t i o n a p p e a r s t o d i s t i n g u i s h them i n t e r m s o f , p r i m a r i l y , t h e i r s u b j e c t i v e r e p o r t o f d i s a b i l i t y and, s e c o n d a r i l y , t h e d e g r e e of p s y c h o l o g i c a l d i s t r e s s t h e y a r e e x p e r i e n c i n g r e g a r d i n g t h e i r c o n d i t i o n . T h u s , the e x p r e s s i o n of an e x a g g e r a t e d p a i n p r e s e n t a t i o n a p p e a r s t o be more r e f l e c t i v e of t h e c o n c e r n s a b o u t how t h e c h r o n i c p a i n p r o b l e m i s a f f e c t i n g t h e 122 i n d i v i d u a l ' s d a i l y l i f e and i s an a t t e m p t by t h a t i n d i v i d u a l t o e x p r e s s h i s / h e r d i s t r e s s t o t h e h e a l t h c a r e p r o f e s s i o n a l . T h e s e c o n c e r n s may n o t n e c e s s a r i l y r e s u l t i n i n c r e a s e d s o m a t i c v i g i l a n c e and a r e as l i k e l y t o o c c u r i n p a t i e n t s w i t h or w i t h o u t c l e a r o r g a n i c p a t h o l o g y . The e x i s t e n c e of p s y c h o l o g i c a l d i s t r e s s ( p o o r c o p i n g a b i l i t y , a n x i e t y , and d e p r e s s i o n ) , however, a p p e a r s t o a f f e c t t h e e x p e r i e n c e of p a i n i n t h a t t h e p a i n i s r a t e d as b e i n g more i n t e n s e . G e nder d i f f e r e n c e s were f o u n d i n t h i s i n v e s t i g a t i o n w i t h women r e p o r t i n g g r e a t e r f u n c t i o n a l d i s a b i l i t y t h a n men. In a d d i t i o n , women were b e t t e r a b l e t o d i s c r i m i n a t e p a i n f u l s t i m u l i i m p l y i n g t h e y a r e more s e n s i t i v e . F i n a l l y , women r a t e d t h e s t i m u l i as more i n t e n s e and u n p l e a s a n t t h a n men. A s i g n i f i c a n t g e n d e r by g r o u p i n t e r a c t i o n was f o u n d f o r t h e r e s p o n s e b i a s t o r e p o r t s e n s a t i o n s as p a i n f u l . W i t h i n t h e g r o u p o f p a i n - f r e e i n d i v i d u a l s , men were l e s s l i k e l y t o l a b e l s e n s a t i o n s as p a i n f u l t h a n women. However, w i t h i n t h e c h r o n i c p a i n g r o u p s , men were more l i k e l y t o l a b e l s e n s a t i o n s as p a i n f u l t h a n women. P a s t r e s e a r c h on g e n d e r d i f f e r e n c e s i n p a i n e x p e r i e n c e and r e p o r t have been m i x e d ; however, women a r e g e n e r a l l y r e p o r t e d t o have l o w e r p a i n t h r e s h o l d s and t o l e r a n c e l e v e l s t h a n men. The r e l a t i o n s h i p between g e n d e r , c h r o n i c p a i n , and p a i n p e r c e p t i o n r e m a i n s u n c l e a r and more c o n t r o l l e d r e s e a r c h i s n e e d e d t o c l a r i f y t h e s e r e s u l t s . The r e s u l t s o f t h i s i n v e s t i g a t i o n s u p p o r t t h e c u r r e n t t r e n d i n t h e l i t e r a t u r e t o w a r d m u l t i d i m e n s i o n a l a s s e s s m e n t s of p a i n p r o b l e m s . I t i s r e c o g n i z e d t h a t t w o - d i m e n s i o n a l models of p a i n a r e o v e r l y s i m p l i s t i c and a t t e m p t s a r e b e i n g made t o a d o p t m u l t i d i m e n s i o n a l m o d e ls t h a t a s s e s s p s y c h o l o g i c a l , s o c i o e c o n o m i c , and p h y s i o l o g i c a l f a c t o r s as t h e y r e l a t e t o p a i n and c h r o n i c i t y ( M a i n & W a d d e l i , 1984; T u r k & Rudy, 1987a; 1987b; W a d d e l i e t a l . , 1 9 89). S i m p l e d i c h o t o m o u s c l a s s i f i c a t i o n schemes ( w h e t h e r o r g a n i c / f u n c t i o n a 1 o r m e d i c a l l y i n c o n g r u e n t / c o n g r u e n t ) f o r c h r o n i c p a i n a r e i n s u f f i c i e n t i n c h a r a c t e r i z i n g t h e d i m e n s i o n s of t h e p r o b l e m f o r t h a t i n d i v i d u a l . However, the a s s e s s m e n t of m e d i c a l l y i n c o n g r u e n t s i g n s and symptoms i s v a l u a b l e i n i d e n t i f y i n g p a t i e n t s who a r e more d i s t r e s s e d by t h e i r p l i g h t and who may n eed a d d i t i o n a l h e l p i n l e a r n i n g how t o c o p e . M u l t i d i m e n s i o n a l e x p l a n a t i o n s of p a i n ( i . e . , e x p l a n a t i o n s o f t h e c o g n i t i v e and a f f e c t i v e r o l e s i n p a i n i n a d d i t i o n t o p h y s i o l o g i c a l e x p l a n a t i o n s ) need t o be g i v e n t o a l l p a i n p a t i e n t s so t h a t t h e y do n o t become d e p e n d e n t upon f i n d i n g a s o l e p h y s i c a l c a u s e and r e s e n t o r r e j e c t any o t h e r e x p l a n a t i o n s f o r t h e i r c o n t i n u e d d i s c o m f o r t . I t i s u n l i k e l y t h a t a l t e r e d p a i n p e r c e p t i o n i s a m a j o r f a c t o r i n t h e m a i n t e n a n c e o f c h r o n i c p a i n but r a t h e r , i s an i n d i c a t i o n of t h e i n d i v i d u a l ' s a p p r a i s a l of t h e p r o b l e m . F u t u r e r e s e a r c h s h o u l d a d d r e s s th e c a u s a l s p e c u l a t i o n s a r i s i n g o u t of t h i s c o r r e l a t i o n a l s t u d y . F o r e x ample, i t w o u l d be v a l u a b l e t o e s t a b l i s h what f a c t o r s l e a d t o an i n c r e a s e i n s o m a t i c v i g i l a n c e , how t h i s may a f f e c t a p a t i e n t ' s e x p e r i e n c e and r e p o r t of p a i n , and what k i n d s o f p r e v e n t i v e s t r a t e g i e s would a l l e v i a t e e x c e s s i v e s o m a t i c v i g i l a n c e . 124 REFERENCES A h l c s . T.A., B l a n c h a r d , E.B., & L e v e n t h a l , H. ( 1 9 8 3 ) . C o g n i t i v e c o n t r o l ot p a i n : A t t e n t i o n t o t h e s e n s o r y a s p e c t s ot t h e c o l d p r e s s o r s t i m u l u s . C o g n i t i v e T h e r a p y and R e s e a r c h , 7_, 1 5 9 - 1 7 8 . A m e r i c a n P s y c h i a t r i c A s s o c i a t i o n ( 1 9 8 7 ) . D i a g n o s t i c and S t a t i s t i c a l Manual of M e n t a l D i s o r d e r s ( 3 r d . e d i t i o n , r e v i s e d ) . W a s h i n g t o n , D.C.: a u t h o r . A r c h e r , J . ( 1 9 7 6 ) . B i o l o g i c a l e x p l a n a t i o n s of p s y c h o l o g i c a l sex d i f f e r e n c e s . In B. L l o y d & J . A r c h e r ( E d s . ) , E x p l o r i n g Sex D i f f e r e n c e s ( p p . 2 4 1 - 2 6 6 ) . New Y o r k : A c a d e m i c P r e s s . B a n d u r a , A., O ' L e a r y , A., T a y l o r , C. 3 . , G a u t h i e r , J . , & G o s s a r d , D. ( 1 9 8 7 ) . P e r c e i v e d s e l f - e f f i c a c y and p a i n c o n t r o l : O p i o i d and n o n o p i o i d m e c h a n i s m s . J o u r n a l of P e r s o n a l i t y and S o c i a l P s y c h o l o g y , 5 3 , 5 6 3 - 5 7 1 . B a r n e s , D., S m i t h , D. G a t c h e l , R. J . , & Mayer, T. G. ( 1 9 8 9 ) . P s y c h o s o c i o e c o n o m i c p r e d i c t o r s of t r e a t m e n t s u c c e s s / f a i l u r e i n c h r o n i c l o w - b a c k p a i n p a t i e n t s . S p i n e , _ 1 4 . < 4 > r 4 2 7 - 4 3 0 . B e l l i s s i m o , A. & T u n k s , E. ( 1 9 8 4 ) . C h r o n i c p a i n : The p s y c h o t h e r a p e u t i c s p e c t r u m . New Y o r k : P r a e g e r . B i g o s , S. J . & B a t t i e , N. C. ( 1 9 8 7 ) . A c u t e c a r e t o p r e v e n t back d i s a b i l i t y . C l i n i c a l O r t h o p a e d i c s and R e l a t e d R e s e a r c h , 22 1 , 1 2 1 - 1 2 8 . B i g o s , S. J . , B a t t i e , M. C., S p e n g l e r , D. M., F i s h e r , L. D., F o r d y c e , W.E., H a n s s o n , T. H., Nachemson, A. L., & Wort l e y , M. D. ( 1 9 9 1 ) . A p r o s p e c t i v e s t u d y of work p e r c e p t i o n s and p s y c h o s o c i a l f a c t o r s a f f e c t i n g t h e r e p o r t o f back i n j u r y . S p i n e , 1 6 ( 1 ) , 1 - 6 B l i s h e n , B. R., C a r r o l l , W. K . , Se Moore, C. ( 1 9 8 7 ) . The 1 9 8 1 s o c i o e c o n i m i c i n d e x f o r o c c u p a t i o n s i n C a n a d a . Review of C a n a d i a n S o c i o l o g y and A n t r o p o l o g y , 2 4 ( 4 ) , 4 6 5 - 4 8 8 . Bobey, M. J . & D a v i d s o n , P. 0 . ( 1 9 7 0 ) . P s y c h o l o g i c a l f a c t o r s a f f e c t i n g p a i n t o l e r a n c e . J o u r n a l of P s y c h o s o m a t i c R e s e a r c h , 1 4 , 3 7 1 - 3 7 6 . Bowers, K . ( 1 9 6 8 ) . P a i n , a n x i e t y , and p e r c e i v e d c o n t r o l . J o u r n a l of C l i n i c a l and C o n s u l t i n g P s y c h o l o g y , 3 2 , 5 9 6 - 6 0 2 . 125 B r a d i s h , D. F., L l o y d , G. J . , Aldam, C. H., A l b e r t , J . , Dyson, P., Doxer, N. C., & M i t s o n , G. L. ( 1 9 8 8 ) . Do n o n o r g a n i c s i g n s h e l p to p r e d i c t the r e t u r n t o a c t i v i t y of p a t i e n t s w i t h low-back p a i n . S p i n e , 1_3 ( 5 ) , 557-560. B r a n d s , A. E. & Schmidt, A. J . ( 1 9 8 7 ) . L e a r n i n g p r o c e s s e s i n the p e r s i s t e n c e b e h a v i o u r of c h r o n i c low back p a i n p a t i e n t s w i t h r e p e a t e d a c u t e p a i n s t i m u l a t i o n . P a i n , 3 0, 329-337. 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C o g n i t i v e P s y c h o l o g y and E m o t i o n a l D i s o r d e r s . New Y o r k : W i l e y . Yang, J . C , Wagner, J . M., & C l a r k , W. C. ( 1 9 8 3 ) . P s y c h o l o g i c a l d i s t r e s s and mood i n c h r o n i c p a i n and s u r g i c a l p a t i e n t s : A s e n s o r y d e c i s i o n a n a l y s i s . In J . J . B o n i c a , V. L i n d b l o m , & A. Iggo ( E d s . ) , A d v a n c e s i n P a i n R e s e a r c h and T h e r a p y , V o l . 5 (pp . 901 -906 ) . Yang, J . C., R i c h l i n , D., B r a n d , L., Wagner, H., & C l a r k , W. C. ( 1 9 8 5 ) . T h e r m a l s e n s o r y d e s i c i o n t h e o r y i n d i c e s and p a i n t h r e s h o l d i n c h r o n i c p a i n p a t i e n t s and h e a l t h y v o l u n t e e r s . P s y c h o s o m a t i c M e d i c i n e , 47, 461-468. 135 APPENDIX A N o n o r g a n i c P h y s i c a l S i g n s ( W a d d e l l e t a l . , 1980) N o t e : T h e s e s i g n s a r e e v a l u a t e d d u r i n g r o u t i n e p h y s i c a l e x a m i n a t i o n . I f p r e s e n t , any i n d i v i d u a l s i g n i s s c o r e d as 1 . A. O v e r r e a c t i o n t o e x a m i n a t i o n F a c i a l e x p r e s s i o n M u s c l e t e n s i o n and t r e m o r Co 1 l a p s i n g S w e a t i n g B. T e n d e r n e s s S u p e r f i c i a l Nonana t omi c C. P a i n R e p o r t e d on S i m u l a t i o n T e s t s ( i . e . , bogus t e s t s ) A x i a l l o a d i n g R o t a t i o n D. D i s t r a c t i o n T e s t s S t r a i g h t l e g r a i s i n g E. R e g i o n a l D i s t u r b a n c e s W i d e s p r e a d Weakness S e n s o r v D i s t u r b a n c e s A P P E N D I X B S c o r i n g C r i t e r i a t o r t h e P a i n D r a w i n g ( R a n s l o r d e t a l . , 19 7 6") U n r e a l D r a w i n g s ( p o o r a n a t o m i c l o c a l i z a t i o n , s c o r e s 2 u n l e s s i n d i c a t e d ) a. t o t a l l e g p a i n b. l a t e r a l whole l e g p a i n ( t r t h i g h a l l o w e d ) c. c i r c u m f e r e n t i a d. b i l a t e r a l a n t e a l l o w e d ) e. c i r c u m f e r e n t i a f . b i l a t e r a l f o o t g. use o f a t l e a s i n s t r u c t i o n s ( D r a w i n g s showing " e x p a n s i o n " a. back p a i n r a d i a t i n g t o i i i p e r i n e u m ( e a c h s c o r e s 1 ) b. a n t e r i o r knee p a i n ( s c o r e s c . a n t e r i o r a n k l e p a i n ( s c o r e d . p a i n drawn o u t s i d e t h e o u t d e p e n d i n g on e x t e n t ) o c h a n t e r i c a r e a and l a t e r a l o r " m a g n i f i c a t i o n " of p a i n ac c r e s t , g r o i n , o r a n t e r i o r 1 ) s 1 ) l i n e ( s c o r e s 1 or 2 1 t h i g h p a i n r i o r t i b i a l a r e a p a i n ( u n i l a t e r a l 1 f o o t p a i n ( s c o r e s 1) p a i n ( s c o r e s 1) t f o u r m o d a l i t i e s s u g g e s t e d i n s c o r e s 1 ) " I p a r t i c u l a r l y h u r t h e r e " i n d i c a t o r s ( e a c h s c o r e s 1) a. add e x p l a n a t o r y n o t e s b. c i r c l e p a i n f u l a r e a s c - draw l i n e s t o d e m a r c a t e p a i n f u l a r e a s d. use a r r o w s e. go t o e x c e s s i v e t r o u b l e and d e t a i l i n d e m o n s t r a t i n g t h e p a i n a r e a s u s i n g t h e s y m b o l s s u g g e s t e d "Look how bad I am" i n d i c a t o r s A d d i t i o n a l p a i n f u l a r e a s i n t h e t r u n k , h e a d , n e c k , or u p p e r e x t r e m i t i e s drawn i n . T e n d e n c y t o w a r d t o t a l body p a i n ( s c o r e s 1 or 2 d e p e n d i n g on e x t e n t ) 137 APPENDIX B The P a i n D r a w i n g On t h e human f o r m b e l o w , m a r k w h e r e y o u r numbness o r p a i n i s , u s i n g t h e k i n d o f marks t h a t c o r r e s p o n d t o what y o u f e e l i n e a c h a r e a . Numbness P i n s and N e e d l e s ooooo B u r n i n g x x x x x S t a b b i n g / / / / / A A A A A A c h i n g A A " \ A A 138 APPENDIX C I n a p p r o p r i a t e Symptom I n v e n t o r y ( W a d d e l i e t a l . , 1984) I n t e r v i e w Q u e s t i o n s ("yes" s c o r e s 1 u n l e s s o t h e r w i s e i n d i c a t e d ) 1. Do you g e t p a i n a t t h e t i p of y o u r t a i l b o n e ? 2 . Does y o u r whole l e g e v e r become p a i n f u l ? 3 . Does y o u r whole l e g e v e r go numb? 4. Does y o u r whole l e g e v e r g i v e way? 5 . I n t h e p a s t y e a r , have you had any s p e l l s w i t h v e r y l i t t l e p a i n ? ("no" s c o r e s 1) 6. Have any of t h e t r e a t m e n t s you've had f o r t h e p a i n h e l p e d you i n any way? ("no" s c o r e s 1) 7. Have you e v e r had t o go t o t h e emergency d e p a r t m e n t b e c a u s e o f y o u r back p a i n ? 139 A P P E N D I X D C o n s e n t Form t o r P i l o t S t u d y S u b j e c t s Heat D i s c r i m i n a t i o n Study- K e n n e t h D. C r a i g , Ph.D. De p a r t m e n t ot P s y c h o l o g y UBC ph. 228-3948 Mary L. Mahon, M.A. Dep a r t m e n t ot P s y c h o l o g y UBC ph. 228-5581 The p u r p o s e o f t h i s s t u d y i s to f i n d o u t what t h e a v e r a g e f a i n t p a i n t h r e s h o l d i s f o r h e a t s t i m u l i . F a i n t p a i n t h r e s h o l d r e f e r s t o t h e p o i n t where you f e e l a s m a l l , d i s t i n c t , p r i c k i n g s e n s a t i o n a t t h e e n d o f a t h r e e s e c o n d e x p o s u r e t o a h e a t s o u r c e . Heat w i l l be g e n e r a t e d by a l i g h t beam t h a t i s shone on t h e s k i n o f y o u r f o r e a r m w h i c h w i l l be p a i n t e d b l a c k w i t h an e a s i l y removed w a t e r - b a s e d p a i n t . I n t e n s i t i e s w i l l r a n g e f r o m warm to f a i n t l y p a i n f u l . S t i m u l i l a s t t h r e e s e c o n d s o r l e s s i f you c h o o s e to s t o p i t s o o n e r . A f t e r e a c h s t i m u l u s , you s i m p l y have t o i n d i c a t e w h e t h e r you f e l t a p r i c k l y s e n s a t i o n o r n o t and you w i l l have 12 s e c o n d s between s t i m u l i t o make t h i s j u d g e m e n t . T h i s e x p e r i m e n t w i l l t a k e 20 m i n u t e s of y o u r t i m e f o r w h i c h you w i l l be p a i d $5.00. You a r e f r e e t o w i t h d r a w f r o m t h e e x p e r i m e n t a t any t i m e and you w i l l s t i l l be p a i d f o r v o u r p a r t i c i p a t i o n . D a t a o b t a i n e d i n t h i s e x p e r i m e n t w i l l be k e p t c o n f i d e n t i a l and u s ed f o r r e s e a r c h o n l y . To e n s u r e a n o n y i t y . v o l u n t e e r s w i l l be i d en t i f i ed by a number. Thank y ou f o r y o u r t i m e and i f you ha v e any q u e s t i o n s a b o u t t h i s s t u d y , do n o t I a g r e e t o p a r t i c i p a t e i n t h i s s t u d y s u b j e c t t o t h e c o n d i t i o n t h a t t h e i n f o r m a t i o n i s k e p t i n c o n f i d e n c e and u s e d f o r r e s e a r c h o n l y . I am aware t h a t I can s t o p my p a r t i c i p a t i o n a t any t i m e w i t h o u t p e n a l t y . I a l s o a c k n o w l e d g e t h a t I have r e c e i v e d a C O D V o f t h i s f o r m . S i g n a t u r e Date 1 4 0 APPENDIX E C o n s e n t Form t o r Chr on i c P a i n P a r t i c i p a n t s H e a t D i s c r i m i n a t . i o n 5 c a ci v K e n n e t h D. C r a i g , Ph.D Mary L. Mahon, M. A. D e p a r t m e n t ot P s y c h o l o g y D e p a r t m e n t ot P s y c h o l o g y UBC ph. 228-3948 UBC ph. 228-5581 We a r e i n t e r e s t e d i n how d i f f e r e n t c h r o n i c p a i n c o n d i t i o n s a f f e c t a p e r s o n 1 s ab i 1 i t y t o d i s c r i m i n a t e betwe en d i f f e r e n t h e a t i n t e n s i t i e s We a r e a l s o i n t e r e s t e d i n whe t h e r p e r c e p t i o n s o f v a r i o u s l e v e l s o f he a t a r e a f f e c t e d by y o u r t h o u g h t s and moods. T h i s r e s e a r ch may c o n t r i b u t e t o more e f f e c t i v e t r e a t m e n t s f o r c h r o n i c pa i n c o n d i t i o n s . F o r t h i s r e a s o n , we a r e r e q u e s t i n g 1 hou r of y o u r t i m e f o r w h i c h yo u w i l l be p a i d $20.00 f o r y o u r p a r t i c i p a t i o n . Your p a r t i c i p a t i o n w i l l i n v o l v e h a v i n g f o u r black, s p o t s p a i n t e d on e a c h f o r e a r m . The b l a c k p a i n t i s e a s i l y removed w i t h soap and w a t e r . Heat w i l l be g e n e r a t e d by a l i g h t beam t h a t i s shone on one o f t h e s e b l a c k s p o t s and i n t e n s i t i e s w i l l r a n g e f r o m warm t o m i l d l y . p a i n f u l . S t i m u l i w i l l l a s t t h r e e s e c o n d s o r l e s s i f you c h o o s e t o s t o p i t s o o n e r . Your t a s k i s t o d i s t i n g u i s h between h e a t s e n s a t i o n s and t h e f i r s t h i n t of f a i n t p a i n . T h i s f a i n t p a i n s e n s a t i o n f o r h e a t has been d e s c r i b e d as a d i s t i n c t , sharp., p r i c k i n g s e n s a t i o n . A f t e r e a c h s t i m u l u s , you s i m p l y have t o i n d i c a t e w h e t h e r you f e l t a p r i c k l y s e n s a t i o n o r n o t and you w i l l have 12 s e c o n d s between s t i m u l i t o make t h i s j u d g e m e n t . You w i l l a l s o be a s k e d t o f i l l o u t some s h o r t q u e s t i o n n a i r e s t h a t e v a l u a t e y o u r t h o u g h t s , moods, and p a i n e x p e r i e n c e . I n o r d e r t o e v a l u a t e d i f f e r e n t p a i n c o n d i t i o n s , we need t o l o o k a t d i a g n o s t i c , l a b o r a t o r y , and m e d i c a l e x a m i n a t i o n d a t a r e l a t e d to y o u r back p r o b l e m f r o m th e S h a u g h n e s s y H o s p i t a l . We w i l l be happy to answer any f u r t h e r q u e s t i o n s you have a b o u t t h e s t u d y and a d e t a i l e d e x p l a n a t i o n of t h e h y p o t h e s e s and r e s e a r c h w i l l be g i v e n a t t h e end o f y o u r p a r t i c i p a t i o n . A l l of t h e i n f o r m a t i o n you p r o v i d e w i l l be k e p t c o n f i d e n t i a l and u s e d f o r r e s e a r c h o n l y . To e n s u r e a n o n y m i t y , v o l u n t e e r s w i l l be i d e n t i f i e d by a number. We would a p p r e c i a t e y o u r h e l p and c o o p e r a t i o n but you a r e f r e e t o r e f u s e o r s t o p y o u r p a r t i c i p a t i o n a t any t i m e . You w i l l be p a i d $10.00 f o r p a r t i c i p a t i n g even i f you d e c i d e p a r t way t h a t you do n o t want t o f i n i s h t h e e x p e r i m e n t . S i n c e t h i s s t u d y i s i n d e p e n d e n t o f t h e S h a u g h n e s s y H o s p i t a l , w h e t h e r you c h o o s e t o p a r t i c i p a t e o r n o t w i l l i n no way a f f e c t y o u r t r e a t m e n t at the h o s p i t a l . Thank you f o r y o u r t i m e . 141 I a g r e e t o p a r t i c i p a t e i n t h i s s t u d y and g i v e p e r m i s s i o n to t h e S h a u g h n e s s y H o s p i t a l t o r e l e a s e m e d i c a l i n f o r m a t i o n s o l e l y f o r t h e p u r p o s e s of t h i s i n v e s t i g a t i o n and s u b j e c t to t h e c o n d i t i o n t h a t t h i s i n f o r m a t i o n i s k e p t i n s t r i c t c o n f i d e n c e . I am aware t h a t I c a n s t o p my p a r t i c i p a t i o n a t any t i m e w i t h o u t j e o p a r d y t o m e d i c a l c a r e . I a l s o a c k n o w l e d g e t h a t I have r e c e i v e d a copy o f t h i s f o r m . S i g n a t u r e Date 142 APPENDIX F I n s t r u c t i o n s t o r P a i n P e r c e p t i o n Task We a r e i n t e r e s t e d i n how w e l l you can d i s t i n g u i s h heat trom a p r i c k l y s e n s a t i o n t h a t we c o n s i d e r to be t h e f i r s t t r a c e ot p a i n . T h i s p r o c e d u r e i s not a t e s t ot y o u r a b i l i t y ot how much p a i n you can t a k e , but r a t h e r i s a t e s t of your a b i l i t y to p e r c e i v e the f i r s t t r a c e of p a i n . T h i s f a i n t l y p a i n f u l f e e l i n g has been d e s c r i b e d as a d i s t i n c t , s h a r p , v e r y s m a l l p r i c k i n g s e n s a t i o n . The f i r s t t r a c e of t h i s means when you j u s t f e e l the p i n - p r i c k at the e x a c t end of t h e t h r e e s e c o n d s t h a t the h e a t i s on. Your t a s k i s d e t e c t t h i s s e n s a t i o n w h i c h w i l l be f e l t i n a d d i t i o n t o the warmth and h e a t . I t i s not e a s y and, t h e r e f o r e , you w i l l have to c o n c e n t r a t e c l o s e l y on t h e s e n s a t i o n s you a r e e x p e r i e n c i n g . A v a r i e t y of h e a t i n t e n s i t i e s w i l l be a p p l i e d to your arm. Some w i l l f e e l o n l y warm, o t h e r s h o t t e r , and some w i l l a l s o f e e l l i k e the h e a t has f o c u s s e d i n on your s k i n and g i v e n you a b i t of a p i n p r i c k . Your t a s k i s t o s i m p l y judge whether you f e l t t h e p i n p r i c k j u s t a t the end o f the s t i m u l u s or n o t . The h e a t i s p r o d u c e d by a l i g h t b u l b t h a t w i l l g o o n f o r e x a c t l y t h r e e s e c o n d s . You a r e to p l a c e the end of the heat gun d i r e c t l y on t h e s u r f a c e of your s k i n . The end of the heat gun i s c o v e r e d by a h e a t r e s i s t a n t r i n g so i t w i l l not f e e l hot a g a i n s t y o u r s k i n . I w i l l p r e s s t h i s r e d b u t t o n and the l i g h t w i l l s t a y on f o r t h r e e s e c o n d s . For e a c h s t i m u l u s , change the he a t gun t o t h e nex t s p o t . Always move to a next spot because o t h e r w i s e , one s p o t w i l l become s e n s i t i v e . 143 B e c a u s e t h i s i s n o t an e a s y t a s k , i t i s i m p o r t a n t f o r you t o be f a m i l i a r w i t h t h e t y p e o f s e n s a t i o n s you w i l l be f e e l i n g . I w i l l s t a r t a t a low l e v e l . You s h o u l d f e e l some warmth. ( A d m i n i s t e r s t i m u l u s a t 1 5 0 ) . Now I w i l l g i v e you a warmer one. ( a d m i n i s t e r s t i m u l u s a t 2 4 0 ) . D i d you f e e l a p r i c k l y s e n s a t i o n t o w a r d t h e end of t h e t h r e e s e c o n d s ? O . K . I w i l l g i v e you some more e x a m p l e s . Look f o r t h e p r i c k l y s e n s a t i o n a t t h e end o f t h e s t i m u l u s . I f you f i n d any o f them t o o u n c o m f o r t a b l e , s i m p l y t a k e t h e h e a t gun away f r o m y o u r s k i n . ( A d m i n i s t e r a r a n g e of s t i m u l i , e m p h a s i z i n g th e ones where the s u b j e c t r e p o r t s t h e p i n p r i c k ) Good, you seem t o have t h e i d e a . We w i l l now j u s t do some more of t h e same t h i n g . A l l you have to do i s put t h e h e a t gun mouth on a d i f f e r e n t b l a c k s p o t e a c h t i m e and c o n c e n t r a t e on t h e s e n s a t i o n . You w i l l have 12 s e c o n d s between e a c h s t i m u l u s t o judge w h e t h e r you f e l t t h a t f i r s t t r a c e of p a i n ( t h e p i n - p r i c k ) o r n o t . ( A d m i n i s t e r two r u n s of t h e Up-Down T h r e s h o l d d e t e r m i n a t i o n ) . APPENDIX G 1 Data Sheet f o r SDT Task SDT DATA S H E E T SEX S K I N TEMPERATURE . AGE ROOM TEMPERATURE . CONTROL GROUP E X P E R I M E N T A L GROUP . M E D I C A T I O N S : T Y P E DOSAGE DEMOGRAPHICS •• MARITAL S T A T U S . E N G L I S H SECOND LANGUAGE . EMPLOYMENT S T A T U S ; . HAD P R E V I O U S SURGERY - M U L T I P L E S U R G E R I E S . F I N A N C I A L COMPENSATION . P R A C T I C E T R I A L S - 1. 2 9. 2 17. 1 25. 3 2. 3 10. 3 18. 2 26. 4 3. 1 11. 1 17. 3 27. 1 4. 4 12. 4 20. 4 28. 2 5. 4 13. 3 21. 4 29. 3 6. 2 14. 1 22. 1 30. 4 7. 1 15. 4 23. 2 31. 2 8. 3 16. 2 24. 3 32. 1 E X P E R I M E N T A L T R I A L S ' 1. 3 9. 2 17. 1 25. 2 33. 3 2. 2 ID. 3 18. 4 26. 3 34. 4 3. 1 11. 1 19. 3 27. 4 35. 1 4. 4 12. 4 20. 2 28. 1 36. 2 5. 3 13. 3 21. 2 29. 1 37. 1 6. 4 14. 1 22. 4 30. 3 38. 2 7. 2 IS. 4 23. 3 31. 4 39. 4 8. 1 16. 2 24. 1 32. 2 40. 3 41. 3 49. 2 57. 4 65. 2 73. 1 42. 4 50. 1 58. 2 66. 4 74. 2 43. 1 51. 4 59. 1 67. 1 75. 3 44. 2 52. 3 60. 3 66. 3 76. 4 45. 2 53. 4 61. 4 69. 1 77. 4 46. 1 54. 2 62. 1 70. 4 78. 1 47. 4 55. 1 63. 3 71. 2 79. 2 48. 3 56. 3 64. 2 72. 3 80. 3 145 APPENDIX H D e b r i e t i n g ot P a r t i c i p a n t s Heat D i s c r i m i n a t i o n S t u d y K e n n e t h D. C r a i g , Ph.D. Mary L. Mahon, M.A. D e p a r t m e n t ot P s y c h o l o g y D e p a r t m e n t ot P s y c h o l o g y UBC ph. 228-3948 UBC oh. 228-5581 Tha nk you f o r y o u r pa r t i c i p a t i o n i n t h i s s t u d y . The p u r p o s e o f t h i s s t udy wa s t o t e s t y o u r t hr e sho l d f o r f a i n t p a i n us i ng r a d i a n t h e a t . T h e r e f o r e , we a s k e d you to i d e n t i f y t h e po i n t where y ou f e l t a d i s t i nc t p i n - p r i c k a t t h e end of a t h r e e s e c o n d e x p o s u r e to a l i g h t beam. T h e r e i s r e s e a r c h t o s u g g e s t p a i n p e r c e p t i o n i s a l t e r e d i n c h r o n i c p a i n p a t i e n t s but i t i s u n c l e a r as t o how i t d i f f e r s f r o m p e o p l e w i t h o u t c h r o n i c p a i n . T h i s s t u d y i s a p r e l i m i n a r y s t u d y f o r a m a j o r r e s e a r c h p r o j e c t t h a t i s d e s i g n e d t o l o o k a t d i f f e r e n c e s i n p a i n s e n s i t i v i t y among d i f f e r e n t t y p e s of c h r o n i c p a i n p a t i e n t s . The s e n s i t i v i t y ot p a i n p a t i e n t s w i l l be compared t o t h e s e n s i t i v i t y of p e o p l e who do n o t e x p e r i e n c e c h r o n i c p a i n . On t h e b a s i s , of the a v e r a g e p a i n t h r e s h o l d t h a t we e s t a b l i s h i n t h i s p r e l i m i n a r y s t u d y , d i f f e r e n t l e v e l s of h e a t i n t e n s i t i e s w i l l be s e l e c t e d f o r a s u b s e q u e n t t e s t o f b o t h c h r o n i c p a i n p a t i e n t s and a n o n - p a i n g r o u p . T h i s r e s e a r c h w i l l c o n t r i b u t e t o our u n d e r s t a n d i n g o f how p a i n p e r c e p t i o n i s a f f e c t e d i n p e o p l e who e x p e r i e n c e c h r o n i c p a i n . I f you a r e i n t e r e s t e d i n f u r t h e r i n f o r m a t i o n , we would be happy t o answer y o u r q u e s t i o n s . 146 A P P E N D I X I C o n s e n t Form t o r C o n t r o l S u b j e c t Heat D i s c r i m i n a t i o n S t u d y K e n n e t h D. C r a i g , Ph.D. D e p a r t m e n t ot P s y c h o l o g y UBC ph. 228-3948 Mary L. Mahon, M.A. D e p a r t m e n t ot P s y c h o l o g y UBC ph. 228-5581 We a r e i n t e r e s t e d i n w h e t h e r p e o p l e e x p e r i e n c i n g c h r o n i c p a i n d i f f e r f r o m p a i n - f r e e i n d i v i d u a l s as t o t h e i r a b i l i t y to d i s c r i m i n a t e between d i f f e r e n t h e a t i n t e n s i t i e s . In o r d e r to do t h i s , we need to t e s t t h e h e a t d i s c r i m i n a t i o n a b i l i t y i n p e o p l e w i t h o u t c h r o n i c pa i n c ond i t i o n s w h i c h i s why y o u a r e b e i n g a s k e d t o v o 1 u n t e e r . We a r e a l s o i n t e r e s t e d i n wh e t h e r p e r c e p t i o n s of v a r i o u s l e v e 1 s of h e a t a r e a f f e c t e d b y V o u r t h o u g h t s and mo ods . F o r t h i s r e a s on, we a r e r e q u e s t i ng 1 hour o f y o u r t ime f o r wh i c h y o u w i 11 be p a i d $20.00 f o r y o u r p a r t i c i p a t i o n . T h i s r e s e a r c h w i l l c o n t r i b u t e t o a g r ea t e r u n d e r s t a n d i n g o f c h r o n i c p a i n and may l e a d t o more e f f e c t i v e t r ea tmen t s. You r p a r t i c i p a t i o n w i l l i n vo 1 V e hav i n g f o u r b l a c k s P o t s p a i n t e d on e a c h f o r e a r m . The b 1 ac k p a i n t i s e a s i i y r e mo v e d w i t h s oa p and wat e r . Heat wi 11 be g e n e r a t ed by a 1 i ght b e am t h a t i s shone on one of t h e s e b 1 ac k s p o t s and i n t ens i t i e s w i l l r ang e f r om warm t o m i l d l y p a i n f u 1 . S t i mu1 i w i l l l a s t t h r e e s e c o n d s o r l e s s i f you c h o o s e t o s t op i t s oone r . Yo u r t a s k i s t o d i s t i n g u i s h be tween h e a t s e n s a t i ons and t h e f i r s t h i n t of f a i n t p a i n . T h i s f a i n t p a i n s e n s a t i o n f o r h e a t has been d e s c r i b e d as a d i s t i n c t , s h a r p , p r i c k i "8 s e n s a t i on. A f t e r e a c h s t i m u l u s , you s i m p l y have t o i nd i c a t e whe t h e r you f e l t a p r i c k l y s e n s a t i o n o r n o t and you wi 11 ha v e 12 se c ond s be t w e en s t i m u l i t o make t h i s j u dgment. You w i 11 a 1 so be a s k e d t o f i l l o u t some s h o r t q u e s t i o n n a i r e s t h a t e va 1 ua t e y o u r t h o u g h t s , moods, and p a i n e x p e r i e n c e . We w i l 1 b e h a P p y t o answer an V f u r t h e r q u e s t i o n s you have a b o u t t h e s t u d y and a d e t a i 1 e d e x p l a n a t i o n of the h y p o t h e s e s and r e s e a r c h w i l l be g i v e n a t t h e end of y o u r p a r t i c i p a t i o n . A l l of t h e i n f o r m a t i o n you p r o v i d e w i l l be k e p t c o n f i d e n t i a l and u s e d f o r r e s e a r c h o n l y . To e n s u r e a n o n y m i t y , v o l u n t e e r s w i l l be i d e n t i f i e d by a number. We would a p p r e c i a t e y o u r h e l p and c o o p e r a t i o n but you a r e f r e e t o r e f u s e o r s t o p y o u r p a r t i c i p a t i o n a t any t i m e . You w i l l be p a i d $10.00 f o r p a r t i c i p a t i n g even i f you d e c i d e p a r t way t h a t you do not want t o f i n i s h t h e e x p e r i m e n t . Thank you f o r y o u r t i m e . s u b j e c t t o t h e c o n f i d e n c e and u s e d s t o p my I a l s o a c k n o w l e d g e S i g n a t u r e I a g r e e t o p a r t i c i p a t e i n t h i s s t u d y c o n d i t i o n t h a t t h e i n f o r m a t i o n i s k e p t i n f o r r e s e a r c h o n l y . I am aware t h a t I can p a r t i c i p a t i o n a t any t i m e w i t h o u t p e n a l t y , t h a t I have r e c e i v e d a copv o f t h i s f o r m . Date 148 APPENDIX J P h y s i c a l I m p a i r m e n t Index ( W a d d e l l & M a i n , 1984) M a t h e m a t i c c o n s t a n t 28 P a i n p a t t e r n Low back p a i n Back and r e f e r r e d l e g p a i n Roo t p a i n 0 8 _ 2 Time pat t e r n R e c u r r i n g C h r o n i c 4 3 P r e v i o u s f r a c t u r e T r a n s v e r s e p r o c e s s Wedge c o m p r e s s i o n F r a c t u r e d i s l o c a t i o n 1 2 6 P r e v i o u s back, s u r g e r y None One More t h a n one 0 3 6 Root c o m p r e s s i o n - None D o u b t f u l De f i n a t e 0 1 o S u b t o t a l Lumbar f l e x i o n cms X 2 - S t r a i g h t l e g r a i s i n g , w i t h d i s t r a c t i o n ) l e f t ( c h e c k e d /10 - S t r a i g h t l e g r a i s i n g , w i t h d i s t r a c t i o n ) r i g h t ( c h e c k e d /10 - S u b t o t a l - A p p r o x i m a t e t o t a l b o d i l y i m p a i r m e n t X N o t e : S p i n a l s t e n o s i s w i t h n e u r o g e n i c c l a u d i c a t i o n s h o u l d be c o d e d as Back •+• r e f e r r e d l e g p a i n and s c o r e d as 8. The l e f t hand column l i s t s t h e c l i n i c a l o b s e r v a t i o n s f o r w h i c h t h e c o r r e s p o n d i n g l o a d i n g f o r e a c h o b s e r v a t i o n i s e n t e r e d i n t h e r i g h t hand c o l u m n , w h i c h i s added up t o g i v e a p p r o x i m a t e t o t a l b o d i l y i m p a i r m e n t . 149 APPENDIX K O swestrv Low Back P a i n D i s a b i l i t v Q u e s t i o n n a i r e ( F a i r b a n k e t a l . . 1 y 8 U ) The following are statements as to how vour back Dain has a t t e c t e d vour ability to manage in everyday l i r e - P l e a s e answer everv section, and mark in each section only the one box which aDDlies to vou. It two statem en ts in anv one section seem to aDolv to vou, Dick one which most closely describes vour problem 1 . P a i n I n t e n s i t y I can tolerate the oain I have without havine to use nain killers. The D a i n i s bad but I manage without taking p a i n killers. P a i n killers give moderate reliet trom Dain. P a i n killers give very little reliet trom Dain. P a i n killers have no ettect on the nain and I do not use them. P e r s o n a l Care ( W a s h i n g , D r e s s i n g , e t c . ) I can l o o k a t t e r m y s e l t n o r m a l l y w i t h o u t c a u s i n g e x t r a o a i n . I can l o o k a t t e r m y s e l t n o r m a l l y but i t c a u s e s e x t r a D a i n It i s p a i n t u l t o l o o k a t t e r m y s e l t and I am slow and c a r e t u 1 . I need some h e l D but manaee most ot mv p e r s o n a l c a r e . I need helD e v e r y day i n most a s D e c t s ot s e l t c a r e . I do not get d r e s s e d , wash w i t h d i t t i c u l t v and s t a y i n bed . 3. L i l t i n g I can l i f t h e a w weights w i t h o u t e x t r a Dain. I can l i t t heavy w e i g h t s but i t g i v e s e x t r a p a i n . P a i n prevents me trom l i t t i n g heavv weights o t t the t l o o r but I can manage it they a r e conveniently Dositioned, eg. on a t a b l e . P a i n p r e v e n t s me trom l i t t i n g heavy w e i g h t s but I can manage l i g h t t o medium w e i g h t s i t t h e v a r e conveniently positioned. I can l i t t o n l y v e r y light w e i g h t s . I cannot litt or carrv a n y t h i n g at a l l . Wa1 k i n g P a i n does not D r e v e n t me w a l k i n g anv d i s t a n c e . P a i n p r e v e n t s me w a l k i n g more t h a n 1 m i l e . P a i n D r e V e n t s me w a l k i n g more t h a n 1/2 m i l e . P a i n D r e v e n t s me w a l k i n g more than 1/4 m i l e . / I can o n l v walk u s i n g a s t i c k or c r u t c h e d . I am i n bed most ot the time and have t o c r a w l to the t o i l e t . 150 S i t t i n g I c a n s e t i n anv c h a i r a s l o n g a s I 1 i rt e . I c a n o n 1 v s i t i n m v t a v o u r i t e c ha i r as l o n e as I 1 ? a i n D r e v e n t s m e s i t t i n g more than 1 ho u r . Pa i n D r e v e n t s me t r om s i 11 i ng more th a n 1/2 h o u r . P a i n D r e v e n t s me t roni s i 11 i ng more th a n 1 0 m i n u t e s . Pa i n D r e v e n t s m e t r o m s i t t i ng at a 1 1 . S t a n d i n g I c an s t a n d as 1 o n g as I I c an s t and as 1 o n g as I P a i n p r e v e n t s me trom s t P a i n p r e v e n t s me trom s t P a i n p r e v e n t s me trom s t P a i n p r e v e n t s me trom s t S l e e p i n g P a i n does no t D r e vent m e I can s l e e p w e l l on 1 v by Even when I t a k e t a b l e t s Even when I t a k e t a b l e t s s l e e p . Even when I ta k e t a b l e t s s l e e p . P a i n p r e v e n t s me trom s 1 e x t r a p a i n , g i v e s me e x t r a p a i n trom s l e e p i n g w e l l , u s i n g t a b l e t s . I have l e s s t h a n s i x hours s l e e p I have l e s s t h a n t o u r hours I have l e s s t h a n two hours ot Sex L i t e My s e x l i t e i s normal and c a u s e s no e x t r a p a i n . My s e x l i t e i s n o rmal but c au s e s some e x t r a p a i n . My s e x l i t e i s n e a r 1 v no rma 1 bu t i s v e r y p a i n t u l . Mv s e x l i t e i s s e v e r e 1 v r e s t r i c t e d by p a i n . My s e x l i t e i s n e a r 1 v a b s e n t be c a u s e ot p a i n . P a i n p r e v e n t s any sex l i t e at a 1 1 . S o c i a l L i t e Mv s o c i a l l i t e i s normal and g i v e s me no e x t r a p a i n . Mv s o c i a l l i t e i s normal but i n c r e a s e s t h e d e g r e e ot p a i n P a i n has no s i g n i t i c a n t e t t e c t on my s o c i a l l i t e a p a r t trom l i m i t i n g mv more e n e r g e t i c i n t e r e s t s , e.g. danc i n g , etc.' P a i n has r e s t r i c t e d bv s o c i a l l i t e and I do not go out as o t t e n . P a i n has r e s t r i c t e d mv s o c i a l l i t e ot mv home. I have no s o c i a l l i t e b ecause ot p a i n . T r a v e l l i n g I can t r a v e l anvwhere w i t ho ut e x t r a P a i n . I can t r a v e l anvwhere bu t i t g i v e s me e x t r a pa i n . P a i n i s bad b u t I man age 1 o u r n e v s o v e r two hou r s . P a i n r e s t r i c t s me to i ou r ne y s ot 1 e s s t han one hour. P a i n r e s t r i c t s me to s ho r t n e c e s s a r v i o u r n e v s under JJ U m i n u t e s . P a i n p r e v e n t s me trom t r a v e 1 1 i n g e X c e p t to the d o c t o r or h o s p i t a l 151 APPENDIX L G r a c e l y R a t i n g S c a l e ( G r a c e l v e t a l . , 1979") From e a c h column below, c h o o s e one word t h a t b e s t d e s c r i b e s the most p a i n t u l s t i m u l u s p r e s e n t e d . M. E x t r e m e l y I n t e n s e L. V e r y I n t e n s e K. I n t e n s e J . S t r o n g I . S l i g h t l y I n t e n s e H. B a r e l y S t r o n g G. M o d e r a t e F. M i l d E. V e r y M i l d D. Weak C. V e r y Weak B . F a i n t A. No S e n s a t i o n M. V e r y I n t o l e r a b l e L. I n t o l e r a b l e K. V e r y D i s t r e s s i n g J . S l i g h t l y I n t o l e r a b l e I . V e r y A n n o y i n g H. D i s t r e s s i n g G. V e r y U n p l e a s a n t F. S l i g h t l y D i s t r e s s i n g E. Annoy i ng D. U n p l e a s a n t C. S l i g h t l y A n n o y i n g B. S l i g h t l y U n p l e a s a n t A. No D i s c o m i o r t 152 S c o r i n g SENSORY INTENSITY E x t r e m e l y I n t e n s e V e r y I n t e n s e I n t e n s e S t r o n g S l i g h t l y I n t e n s e B a r e l y S t r o n g M o d e r a t e M i l d V e r y M i l d Weak. V e r v Weak F a i n t No S e n s a t i o n t o r G r a c e l y R a t i n g S c a l e s UNPLEASANTNESS 59.5 V e r y I n t o l e r a b l e 44.8 43.5 I n t o l e r a b l e 32.3 34.6 V e r y D i s t r e s s i n g 18.3 2 2.9 S l i g h t l y I n t o l e r a b l e 13.6 21.3 V e r y A n n o y i n g 12.1 12.6 D i s t r e s s i n g 11.4 12.4 V e r y U n p l e a s a n t 10.7 5.5 S l i g h t l y D i s t r e s s i n g 6.2 3.9 A n n o y i n g 5.7 2.8 U n p l e a s a n t 5.6 2.3 S l i g h t l y A n n o y i n g 3.5 1.1 S l i g h t l y U n p l e a s a n t 2.8 0 No D i s c o m f o r t 0 153 APPENDIX M COPING STRATEGY QUESTIONNAIRE Individuals who experience pain have developed a number ot wavs to cope, or deal with, their pain. These include saying things to themselves when thev experience pain, or engaging i n d i t t e r e n t a c t i v i t i e s . Below are a l i s t ot things that patients have reported doing when they t e e l pain. For each a c t i v i t y , please indicate, using the scale below, how much you engage i n that a c t i v i t y when you f e e l pain, where a 0 indicates you never do that when you are experiencing pain, a 3 i n d i c a t e s that you sometimes do that when you experience pain, and a 6 i n d i c a t e s you always do i t when vou experience pain. Remember, you can use any point along the scale. 0 1 2 3 4 5 6 Never Sometimes Alwavs do do t h a t do t h a t WHEN I FEEL PAIN... 1. I try to f e e l distant from the pain, almost as i f the pain was i n somebody else's body. 2. I leave the house and do something, such as going to the movies or shopping. 3. I try to think of something pleasant. 4. I don't think of i t as pain but rather as a d u l l or warm f e e l i n g . 5. It i s t e r r i b l e and I f e e l i t i s never going to get any better. 6. I t e l l myself to be brave and carry on despite the pain. 7. I read. I 8. I t e l l myself that I can overcome the pain. 9. I count numbers i n my head or run a song through my mind. 10. I just think of i t as some other sensation, such as numbness. 11. It i s awful and I f e e l i t overwhelms me. 12. I play mental games with myself to keep my mind o f f the pain. 13. I f e e l my l i f e i s n ' t worth l i v i n g . 14. I know someday someone w i l l be here to help me and i t w i l l go away for awhile. 15. I pray to God i t won't l a s t long. 16. I try not to think of i t as my body, but rather as something separate from me. 17. I don't think about the pain. 18. I try to think years ahead, what everything w i l l be l i k e a f t e r I've gotten r i d of the pain. 19. I t e l l myself i t doesn't hurt. 20. I t e l l myself I can't l e t the pain stand i n the way of what I have to do. i l . I don't pay any a t t e n t i o n to i t . 22. I have f a i t h i n doctors that someday there w i l l be a cure for my pain. 23. No matter how bad i t gets, I know I can handle i t . 24. I pretend i t i s not there. 25. I worry a l l the time about whether i t w i l l end. 26. I replay i n my mind pleasant experiences i n the past. 154 27. I think ot people I enjoy doing things with. 28. I pray for the pain to stop. 29. I imagine that the pain i s outside of my body. 30. I just go on as i f nothing happened. 31. I see i t as a challenge and don't l e t i t bother me. 32. Although i t hurts, I just keep going. 33. I f e e l I can't stand i t any more. 34. I t r y to be around other people. 35. I ignore i t . 36. I r e l y on my f a i t h i n God. 37. I f e e l l i k e I can't go on. 38. I think of things I enjoy doing. 39. I do anything to get my mind o f f the pain. 40 I do something I enjoy, such as watching TV or l i s t e n i n g to music. 41. I pretend i t i s not a part ot me. 42. I do something a c t i v e , l i k e household chores or pro j e c t s . Based on a l l the things you do to cope, or deal with, your pain, on an average day, how much control do you f e e l you have over i t ? Please c i r c l e the appropriate number. Remember, you can c i r c l e any number along the scale. 0 1 2 3 4 5 6 No control Some control Complete control Based on a l l the things you d o to cope, or deal with pain, on an average day, how much are you able to decrease i t ? Please c i r c l e the appropriate number. Remember, You can c i r c l e any number along the scale. r 0 1 Can't decrease i t at a l l 2 3 4 Can decrease i t somewhat 5 6 Can decrease i t completely 155 Key to C o p i n g S t r a t e g y Q u e s t i o n n a i r e C o g n i t i v e c o p i n g s t r a t e g i e s : 1. D i v e r t i n g a t t e n t i o n : 3, 9, 12, 26, 27, 38 2. R e i n t e r p r e t i n g t h e p a i n s e n s a t i o n s : 1, 4 , 10, 16, 29 , 41 3. C a t a s t r o p h i z i n g : 5, 11, 13, 25, 33, 37 4. I g n o r i n g s e n s a t i o n s : 17, 19, 21, 24, 30, 35 5. P r a y i n g o r h o p i n g : 14, 15, 18, 22, 28, 36 6. C o p i n g s e 1 f - s t a t e m e n t s : 6, 8, 20, 23, 31, 32 B e h a v i o u r a l c o p i n g s t r a t e g y 1. I n c r e a s e d b e h a v i o u r a l a c t i v i t i e s : 2, 7, 34, 39, 40 , 42 E f f e c t i v e n e s s r a t i n g s 1. C o n t r o l o v e r p a i n 2. A b i l i t y to d e c r e a s e p a i n . APPENDIX N PAIN EXPERIENCE SCALE Many p e o p l e r e p o r t h a v i n g the f o l l o w i n g k i n d s ot t h o u g h t s and f e e l i n g s when t h e i r p a i n i s v e r y s e v e r e . We would l i k e to know how f r e q u e n t l y you e x p e r i e n c e each of t h e t h o u g h t s and f e e l i n g s l i s t e d below when y o u r p a i n i s v e r y s e v e r e . Read e a c h and t h e n c i r c l e a number on the s c a l e under the s t a t e m e n t to i n d i c a t e how o f t e n you have t h a t t h o u g h t or f e e l i n g . 1. I f e e l f r u s t r a t e d 0 1 2 3 4 5 6 Never Very O f t e n 2. I t h i n k about my p a i n g e t t i n g worse. 0 1 2 3 4 5 6 Never V e r y O f t e n 3. I f e e l i r r i t a b l e . 0 1 2 3 4 5 6 Never V e r y O f t e n , 4 . I am d e p r e s s e d b e c a u s e of my p a i n . 0 1 2 3 4 5 6 Never Very O f t e n 5. I wonder what i t would be l i k e t o n e v e r have any p a i n . 0 1 2 3 4 5 6 Never V e r y O f t e n 6. I f e e l a n g r y . 0 1 2 3 4 5 6 Never V e r y O f t e n 7. I f e e l overwhelmed. 0 1 2 3 4 5 6 Never V e r y O f t e n 8. I f e e l a f r a i d t h a t my p a i n w i l l get w o r s e . 0 1 2 3 4 5 6 Never V e r v O f t e n 157 9. I t h i n k , " T h i s p a i n i s d r i v i n g me c r a z y " . 0 1 2 3 4 5 6 Never Very O f t e n 10. I f e e l i m p a t i e n t w i t h e v e r y b o d y . 0 1 2 3 4 5 6 Never V e r y O f t e n 11. I w o r r y about my f a m i l y . 0 1 2 3 4 5 6 Never Very O f t e n 12. I t h i n k about whether l i f e i s w o r t h l i v i n g . 0 1 2 3 4 5 6 Never V e r y O f t e n 13. I f e e l a n x i o u s . 0 1 2 3 4 5 6 Never Very O f t e n 14. I f e e l d i s a p p o i n t e d w i t h m y s e l f f o r g i v i n g i n the the p a i n 0 1 2 3 4 5 6 Never Very O f t e n 15. I f e e l e v e r y o n e i s g e t t i n g on my n e r v e s . 0 1 2 3 4 5 6 Never ' V e r y O f t e n 16. I t h i n k , " I t i s so h a r d t o do a n y t h i n g when I have p a i n . 0 1 2 3 4 5 6 Never Very O f t e n 17. I wonder how l o n g t h i s w i l l l a s t . 0 1 2 3 4 5 6 Never V e r y O f t e n 18. I t h i n k of n o t h i n g o t h e r t h a n my p a i n . ' 0 1 2 3 4 5 6 Never Very O f t e n 19. I f e e l s o r r y f o r m y s e l f . 0 1 2 3 4 5 6 Never Verv O f t e n 158 S c o r i n g t o r the P a i n E x D c r i c n c c S c a l e S c a l e 1: E m o t i o n a l i t v (01 + 03 + 04 + Ob + 07 + 09 + 010 + 012 + 013 + 015 + 016 + 019) / 13 S c a l e 2: Worrv (02 + 05 + 08 + O i l + 014 + 017) / b 159 APPENDIX 0 T r a i t A n x i e t v Q u e s t i o n n a i r e ( S p e i l b e r g e r , 1985) A number ot s t a t e m e n t s w h i c h p e o p l e have u s e d t o d e s c r i b e t h e m s e l v e s a r e g i v e n below. P l e a s e r e a d e a c h s t a t e m e n t and t h e n put a checkmark i n t h e a p p r o p r i a t e box t o t h e r i g h t o f t h e s t a t e m e n t t o i n d i c a t e how you g e n e r a l l y f e e l . T h e r e a r e no r i g h t o r wrong a n s w e r s . Do n o t spend t o o much time on any one s t a t e m e n t but g i v e t h e answer w h i c h seems t o d e s c r i b e how you g e n e r a l l y f e e l . A l m o s t n e v e r Some t ime s Of t e n A l m o s t a 1wa v s I f e e l p l e a s a n t _ I t i r e q u i c k l y 3. I f e e l l i k e c r y i n g 4. I w i s h I c o u l d be as happy as o t h e r s seem t o b e I am l o s i n g out on t h i n g s b e c a u s e I c a n ' t make up my mind soon enough 6. I f e e l r e s t e d 7. I am " c a l m , c o o l , and c o l l e c t e d " I f e e l t h a t d i f f i c u l t i e s a r e p i l i n g up so t h a t I c a n n o t overcome them I w o r r y t o o much o v e r s o m e t h i n g t h a t r e a l l y d o e s n ' t m a t t e r 10. I am happy 11. I am i n c l i n e d t o t a k e t h i n g s h a r d 12. I l a c k s e 1 f - c on f i dene e_ 13. I f e e l s e c u r e 160 A1mo s t n e v e r Some t i m e s O f t e n A l m o s t a l w a y s 14. I t r y t o a v o i d f a c i n g a c r i s i s o r d i f f i c u l t y 15. I f e e l b l u e 16. I am c o n t e n t 17. Some u n i m p o r t a n t t h o u g h t s ru n t h r o u g h my mind and b o t h e r me 18. I t a k e d i s a p p o i n t m e n t s so k e e n l y t h a t I c a n ' t put them out of mv mind 19. I am a s t e a d y p e r s o n 20. I g e t i n a s t a t e o f t e n s i o n of t u r m o i l as I t h i n k o v e r my r e c e n t c o n c e r n s and i n t e r e s t s

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