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Evaluation of scoliosis screening at Simon Fraser Health District Wynne, Elizabeth Jean 1981

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EVALUATION OF SCOLIOSIS SCREENING AT SIMON FRASER HEALTH DISTRICT by ELIZABETH JEAN WYNNE B.Sc.N., The University of B r i t i s h Columbia, 1957 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE (HEALTH SERVICES PLANNING) i n THE FACULTY OF GRADUATE STUDIES Department of Health Care and Epidemiology We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October 1981 Eliza b e t h Jean Wynne, 1981 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an advanced degree a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I agr e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e head o f my department o r by h i s o r h e r r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Department o f ~lcL*-&-4-^CJt~ (LA-AJL* CK^^A. The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5 i i ABSTRACT This study evaluates s c o l i o s i s screening c a r r i e d out by the Simon Fraser Health D i s t r i c t among grade seven students from September 1976 to June 1980. The r e s u l t s of screening were reviewed to deter-mine i f the evidence of four years of screening substantiates the con-tinuation of the program. The program was i n i t i a t e d with the b e l i e f that detection of s c o l i o s i s at an early stage would allow bracing treatment as an a l t e r n a t i v e to major s p i n a l surgery for correction of s c o l i o s i s curvatures. The c r i t e r i a f o r evaluation of screening programs i n general and s p e c i f i c a l l y f o r s c o l i o s i s screening were selected a f t e r a search of the l i t e r a t u r e . Four p r i n c i p a l c r i t e r i a were u t i l i z e d to evaluate t h i s screening program: the a c c e p t a b i l i t y of the test to the parents, ch i l d r e n and physicians affected by screening, the a c c e p t a b i l i t y of the treatment, the v a l i d i t y of the test and the a v a i l a b i l i t y of resources to carry out the program. Class l i s t s , record cards and previous reports of the program were sources of data on the r e s u l t s of the screening program. Addi-t i o n a l data was gathered during telephone interviews of parents and through questionnaires to physicians. Outcomes of the 169 screening p o s i t i v e s i d e n t i f i e d from the screening population of 8010 boys and g i r l s , p r i m a r i l y grade seven students, were examined and i t was found that r e s u l t s were a v a i l a b l e for 167 of the 169 students screened p o s i t i v e . Of these, 40 (24 percent) i i i were orthopedically p o s i t i v e (curve over 10°by Cobb method), 4 boys and 36 g i r l s f o r a male to female r a t i o of 1:9. Active treatment by brace and/or surgery was recommended for 12 c h i l d r e n , a l l female. There were three r e f u s a l s i n the nine cases i n which bracing was recommended (33.3 percent) and three of the nine chi l d r e n for whom surgery was recommended also refused (33.3 percent). Six c h i l d r e n were braced, but three of these eventually required surg-i c a l c o r r e c t i o n . A t o t a l of s i x chi l d r e n had s p i n a l surgery. Of the 38 curves for which X-ray information i s known, 25 were les s than 20° i n i t i a l l y and 13 were greater than 20°. None of the curves i n i t i a l l y under 20° required treatment. A f o u r f o l d table was presented using an estimate of s c o l i o s i s prevalence to derive t o t a l diseased i n the screening population. Sen-s i t i v i t y of the screening test was estimated at 26.2 percent, s p e c i f i -c i t y at 98.4 percent, o v e r r e f e r r a l at 75.1 percent, underreferral at 1.5 percent and the p o s i t i v e p r e d i c t i v e value at 24.9 percent. Overall p r e d i c t i v e v a l i d i t y was 97 percent. Prevalence of s c o l i o s i s i n SFHD was estimated at 0.6 percent compared to prevalence reported i n the l i t e r a t u r e of 2 percent to 4 percent i n s i m i l a r populations using the same orthopedic standard f o r a p o s i t i v e curve. Costs for the screening program to the health d i s t r i c t were approximately $17,800 for four years. The costs of r e f e r r a l services excluding surgery f o r diagnostic (true) p o s i t i v e s were estimated at $12,250 and costs f o r the f a l s e p o s i t i v e s (orthopedically negative) were $6,325. The conclusion reached was that although, s c o l i o s i s screening has had community acceptance, the a c c e p t a b i l i t y of treatment was ques-tionable, the v a l i d i t y of the test was not supported and that consid-erable resources were consumed. The absence of a ce n t r a l r e f e r r a l c l i n i c was i d e n t i f i e d as a resource d e f i c i e n c y . I t was recommended that the program be discontinued at th i s health d i s t r i c t . Furthermore i t was recommended that s c o l i o s i s screen-ing not be introduced to other areas of the province because of the d i f f i c u l t i e s forseen i n orthopedic evaluation and o r t h o t i c service, as well as because of doubts about v a l i d i t y of the test and a c c e p t a b i l i t y of treatment. Some suggestions were made for modifications should the program be continued at SFH.D and for future studies. V DEDICATION To Tom, Mary and Andrew. v i TABLE OF CONTENTS ABSTRACT i i DEDICATION v TABLE OF CONTENTS v i LIST OF TABLES v i i i LIST OF FIGURES i x ACKNOWLEDGEMENT x CHAPTER I. INTRODUCTION 1 The Hypothesis 2 Description of S c o l i o s i s 2 The Implications of Screening 3 S c o l i o s i s Screening at Simon Fraser Health D i s t r i c t 5 Organization of the Thesis 7 D e f i n i t i o n of Terms Used i n This Study 8 CHAPTER I I . REVIEW OF THE LITERATURE 11 Evaluation of Screening Programs 11 Evaluation C r i t e r i a Applied to S c o l i o s i s and S c o l i o s i s Screening 22 CHAPTER I I I . METHODOLOGY 55 Purpose of the Study 55 Description of the Screening Program 55 Study Method 59 v i i C a l c u l a t i o n of Resources Used 61 Methods of Analysing Program Data . . . . 62 E t h i c a l Review 66 CHAPTER IV. RESULTS OF THE SCREENING PROGRAM 67 A c c e p t a b i l i t y of the Screening Test 67 A c c e p t a b i l i t y of Treatment 70 V a l i d i t y of the Test 74 A v a i l a b i l i t y of Resources 83 CHAPTER V. DISCUSSION 94 Appli c a t i o n of General C r i t e r i a 94 Evaluation by P r i n c i p a l C r i t e r i a 100 CHAPTER VI. CONCLUSION 108 General Recommendations I l l Recommendations f o r Further Study 113 LIST OF REFERENCES 115 APPENDICES A. Introductory Letter to Family 121 B. Interview Format 123 C. Consent for Physician Contact 126 D. Introductory Letter to Physician 128 E. Questionnaire to Physician 130 F. C e r t i f i c a t e of Approval 133 G. Letter of Permission 135 v i i i LIST OF TABLES Table Page I. DEATHS DUE TO SCOLIOSIS AND DUE TO ALL CAUSES B.C. AND CANADA, 1972-1978 27 I I . REFUSAL OF CONSENT FOR SCREENING 68 I I I . TREATMENT OF ORTHOPEDIC POSITIVE CHILDREN 70 IV. REFUSAL OF REFERRAL RECOMMENDATION 73 V. RESULTS OF SCOLIOSIS SCREENING 1976-1980 IN SFHD . . . . 74 VI. SEX OF ORTHOPEDICALLY POSITIVE CASES . 76 VII. FOURFOLD TABLE DERIVED USING PREVALENCE STATISTICS . . . 79 VIII. NUMBER AND RATE OF ORTHOPEDIC POSITIVES PER SCREENING YEAR 82 IX. SFHD RESOURCES UTILIZED IN SCOLIOSIS SCREENING 84 X. NUMBER OF SERVICES PROVIDED FOR ORTHOPEDIC POSITIVES . . 86 XI. NUMBER OF REFERRALS SEEN BY GENERAL PRACTITIONER AND ORTHOPEDIST AND X-RAY STATUS 87 XII. COST OF SERVICES PROVIDED FOR ORTHOPEDIC POSITIVE SCREENEES 88 XIII. SERVICES PROVIDED FOR ORTHOPEDIC NEGATIVE SCREENEES . . 90 XIV. COST OF SERVICES FOR ORTHOPEDIC NEGATIVE SCREENEES . . . 91 XV. SURGERY WITH HARRINGTON ROD (ICD CODE 930.4) IN B.C. BY HOSPITAL APRIL 1, 1979 TO MARCH 31, 1980 93 LIST OF FIGURES Figure Page 1. Factors i n f l u e n c i n g the effectiveness of a screening program 18 2. Fourfold table c l a s s i f y i n g p a r t i c i p a n t s i n a screening program 64 3. A n a l y t i c a l d e r i v a t i o n of the f o u r f o l d table 65 4. Pattern of progress of s c o l i o s i s curves from i n i t i a l to maximum curve 78 ACKNOWLEDGEMENT This study has been f a c i l i t a t e d by the encouragement and cooper-ation of the s t a f f of Simon Fraser Health D i s t r i c t . A s p e c i a l thank you i s extended to Dr. John Blatherwick, Director, who endorsed t h i s program evaluation, to physiotherapists June Moore and Ann Ryder, who shared t h e i r records and expertise and to the c l e r i c a l s t a f f f or t h e i r able assistance i n the preparation and d i s t r i b u t i o n of l e t t e r s of introduc- . t i o n and questionnaires. I wish to express appreciation to my thesis committee - Dr. James Robinson, chairman, and Dr. Annette Stark and Ki r s t e n Weber. Each has provided s p e c i a l advice and guidance to enable the thesis to be produced. Others i n the f i e l d , who have shared t h e i r studies of s c o l i o s i s screening programs, p a r t i c u l a r l y Dr. J . I. Williams, were of consider-able assistance. Dr. E r i c Holowaty provided advice i n the preliminary stages of the study proposal. F i n a l l y I would be remiss i n t h i s acknowledgement i f I did not say a p a r t i c u l a r thank you to the fa m i l i e s who so w i l l i n g l y shared information and fe e l i n g s about the s c o l i o s i s program with me. The physicians of the health d i s t r i c t , p a r t i c u l a r l y Dr. Michael Piper, were also a great assistance i n providing necessary outcome data. 1 CHAPTER I INTRODUCTION Improved health status of i n d i v i d u a l s i n the community i s a primary goal f o r a l l workers i n the f i e l d of public health. As basic standards of environmental health are achieved and communicable diseases c o n t r o l l e d i t i s l o g i c a l that a t t e n t i o n i s focussing on prevention of chronic d i s a b l i n g diseases. Those that a f f e c t c h i l d r e n and a f f l i c t l i f e l o n g d i s a b i l i t y are of s p e c i a l concern to the community health pro-f e s s i o n a l . S c o l i o s i s i s one such disease. Administrators and policy-makers seek a f a c t u a l basis for program decisions with the r e a l i z a t i o n i t i s no longer acceptable to " e y e b a l l " the e f f e c t s of programs i n public health and medicine and thereby judge t h e i r u t i l i t y (Freeman 1978). What i s being sought are systematic, r e p l i c a b l e and precise assessments of both established and innovative programs within the health care f i e l d . Unfortunately most preventive screening has been c a r r i e d out without evidence of i t s health e f f e c t i v e -ness and i n some cases i n d i r e c t c o ntradiction to the a v a i l a b l e evidence (Sackett 1975b). This study proposes to evaluate the e f f o r t s of a public health d i s t r i c t to f i n d cases of s c o l i o s i s early, that i s , before they were c l i n i c a l l y evident, so that conservative treatment would lead to better health for adolescents i n i t s community. There i s recognition that t h i s program has become an accepted part of the public health d e l i v e r y system 2 i n Simon Fraser Health D i s t r i c t (SFHD) but also that the evidence of i t s effectiveness should be examined. The Hypothesis The hypothesis proposed i s that evaluation of the r e s u l t s of four years of screening for s c o l i o s i s at SFHD w i l l substantiate that the screening program should be continued. The p r i n c i p a l c r i t e r i a f o r evaluation that w i l l be applied to the r e s u l t s of screening are the a c c e p t a b i l i t y of the screening t e s t , a c c e p t a b i l i t y of treatment for the disease detected by screening, the v a l i d i t y of the test and the a v a i l a b i l i t y of resources. Consideration w i l l also be given to whether the goal of the program has been met, that i s , whether early detection of s c o l i o s i s and treatment with the Milwaukee brace has eliminated the need for surgery for s c o l i o s i s i n the screened population. To test the hypothesis i t i s necessary to consider the use of screening i n general and as related to the management of s c o l i o s i s i n the community. Description of S c o l i o s i s S c o l i o s i s i s a condition i n which a l a t e r a l curvature of the spine develops leading to r o t a t i o n a l deformity of the vertebrae and r i b s . The curve may progress and r e s u l t i n serious d i s a b i l i t y with impairment of the heart and lungs and a shortened l i f e s p a n . S c o l i o s i s i s c l a s s -i f i e d as non-structural (reversible) and s t r u c t u r a l ( I r r e v e r s i b l e ) . Idiopathic s c o l i o s i s i s a type of s t r u c t u r a l s c o l i o s i s and accounts for about 70 percent of a l l cases of s c o l i o s i s (Keim 1978). While i t may occur i n infancy or the j u v e n i l e years i t i s most common i n adolescence. The cause i s unknown but a genetic factor appears to be present. 3 S c o l i o s i s has affected mankind since the days of the Stone Age. Early drawings on cave walls and evidence i n s k e l e t a l remains have revealed that the disease was present i n our e a r l i e s t ancestors (Keim 1978). Hippocrates used the Greek word " s k o l i o s i s " meaning crooked i n h i s writings and describes the use of f o r c e f u l mechanical means to treat the curves. Indeed treatment of s c o l i o s i s has intrigued and challenged medical p r a c t i t i o n e r s throughout h i s t o r y . Pare i n 1550 applied an i r o n brace a f t e r t r a c t i o n . Exercises and gymnastics were u t i l i z e d i n the 1800's as was surgery followed by the use of a hinged frame. The f i r s t s p i n a l f u sion f o r s c o l i o s i s was performed i n 1914. Modern management includes observation of the curve with bracing or s u r g i c a l treatment of those curves which progress to a serious stage. The Implications of Screening To discover disease at the e a r l i e s t stage i n i t s natural h i s t o r y when measures may be applied to ar r e s t i t s progress or e f f e c t a cure has enormous appeal to the health care p r a c t i t i o n e r concerned about the prevalence of chronic disease.: Screening has held promise as the route to t h i s discovery for the professional seeking to use preventive measures. The goal of screening i s to apply a simple maneuver to a population f o r the purpose of separating these apparently w e l l i n d i v i d u a l s into two d i s t i n c t groups. The d i v i s i o n i s based on the p r o b a b i l i t y of the pre-sence of disease or of a precursor of the disease. The premise i s that early intervention i n the "at r i s k " or diseased group w i l l r e s u l t i n improved outcome. Screening has been a c o n t r o v e r s i a l issue i n recent years. Debate has clouded the merits of accepted maneuvers such as screening for 4 c e r v i c a l cancer. The lack of randomized c l i n i c a l studies at the incep-t i o n of c e r t a i n now widespread screening procedures has been viewed as a c r i t i c a l omission by several s c i e n t i s t s (Cochrane and Holland 1971; McKeown and Knox 1968; Sackett 1975a). Evaluative c r i t e r i a have been established by researchers as the issue of a c c o u n t a b i l i t y for screening programs has evolved as a major concern. Those who question the i n s t i t u t i o n of widespread screening with-out v a l i d a t i o n of i t s effectiveness i n terms of improved health, point out the d i f f e r e n t r e s p o n s i b i l i t y given the professional who screens. As d i s t i n c t from therapeutic medicine, i n screening the health care p r a c t i t i o n e r seeks out an apparently well i n d i v i d u a l and subjects that person to a maneuver to detect unknown disease or d i s a b i l i t y . In ther-apeutic medicine the i n d i v i d u a l seeks medical attention because of symptoms or signs of i l l n e s s and expects assistance i n terms of reason-able current p r a c t i c e . The p r a c t i t i o n e r of screening . . . should have conclusive evidence that screening can a l t e r the natural h i s t o r y of disease i n a s i g n i f i c a n t portion of those screened. (Cochrane and Holland 1971) Of course i t i s not screening i t s e l f which can " a l t e r the natural h i s t o r y " but the a p p l i c a t i o n of e f f e c t i v e interventions. I t i s essen-t i a l that screening of a p r e s c r i p t i v e nature be proven to do more good than harm. This means that there must be knowledge that the c l i n i c a l procedures which may r e s u l t from screening w i l l be of greater b e n e f i t than detriment to the c l i e n t (Sackett 1975a). As w e l l as the e t h i c a l concern of the p r a c t i t i o n e r about e f f e c -tiveness, he i s required to be f i n a n c i a l l y accountable to the government or i n d i v i d u a l s funding his p r a c t i c e or agency. Preventive measures such 5 as screening are sometimes considered to be cost e f f e c t i v e ; the premise i s that early treatment w i l l reduce t o t a l health care costs. In B r i t i s h Columbia the proportion of the p r o v i n c i a l budget allocated to health has r i s e n annually to i t s present l e v e l of 1.975 b i l l i o n or 30 percent of a l l governmental expenditures. There are plans to contain r i s i n g costs by a l l o c a t i n g resources to those programs which have shown themselves to be most e f f e c t i v e . Those making decisions within the M i n i s t r y of Health are therefore considering program evaluation as a means to choose the most e f f e c t i v e use of resources. In t h i s context of governmental and professional concern about the effectiveness of screening t h i s investigator wishes to evaluate the s c o l i o s i s screening program which began at SFHD i n 1976. This i s timely for the reasons given and e s p e c i a l l y because several other p r o v i n c i a l health d i s t r i c t s are considering introducing programs and would benefit from evaluation of the experience at SFHD. S c o l i o s i s Screening at Simon Fraser Health D i s t r i c t Simon Fraser Health D i s t r i c t (SFHD) encompasses the C i t i e s of New Westminster, Port Coquitlam, Port Moody, the Municipality of Coquitlam, the V i l l a g e of Belcarra and E l e c t o r a l Area B, f o r a t o t a l population of about 140,000. I t i s p r i m a r i l y a middle class suburban area with a large number of i t s workforce commuting to jobs i n the nearby c i t y of Vancouver. The school population of the health d i s t r i c t was 26,643 as of September 30th, 1980. I t i s a health d i s t r i c t within the M i n i s t r y of Health of the Province of B r i t i s h Columbia. The Chief Administrative O f f i c e r , the Health D i s t r i c t Director i s responsible to 6 the Assistant Deputy Minister of Preventive Services within the M i n i s t r y of Health. The impetus for i n s t i t u t i n g screening for s c o l i o s i s at SFHD i n January 1976 was concern about the number of major s u r g i c a l procedures performed i n recent years to correct severe s c o l i o t i c curves i n young people within the d i s t r i c t . Surgery was known to have been required i n at l e a s t ten cases i n the community. An orthopedic surgeon and the health u n i t d i r e c t o r together with health d i s t r i c t personnel planned a p i l o t project to examine school c h i l d r e n to assess i f a school screen-ing program could detect the disease at an early stage. From the i n i t i a l project d i s t r i c t - w i d e screening began i n September 1976. The b e l i e f was . . . that a screening program i n the community would discover c h i l d r e n with signs of s c o l i o s i s while s t i l l growing, thus permitting conservative treatment with the Milwaukee brace. (SFHU Report 1977) Reports of e a r l i e r programs such as the statewide program i n Delaware suggested that screening eliminated the need for surgery (Lonstein et a l . 1976). The American Academy of Orthopedic Surgeons had published i t s p o s i t i o n on s c o l i o s i s screening i n 1974 as follows The American Academy of Orthopaedic Surgeons hereby gives i t s o f f i c i a l recommendation to any program of routine examination of school c h i l d r e n for the detection of s c o l i o s i s and other c r i p p l i n g spine deformities. The Academy recognizes that by early detection more appropriate treatment can be given and a better t o t a l treatment of this d i s a b l i n g health problem can be c a r r i e d out. (Lonstein et a l . 1976, p. 52) In s p i t e of the endorsement of this respected body there were other views about the worth of s c o l i o s i s screening. In a 1980 Report of the Canadian Task Force considering P e r i o d i c Health Examinations, 7 the recommendation concerning s c o l i o s i s was There i s no s c i e n t i f i c j u s t i f i c a t i o n for the view that screen-and/or casefinding f o r S c o l i o s i s i s d i s t i n c t l y b e n e f i c i a l . U n t i l better evidence i s established, screening i n a pe r i o d i c health examination should be conducted only within the context of an evaluative study. (Report of a Task Force Considering P e r i o d i c Health Examination 1980, p. 73) In l i g h t of the divergent views on the value of s c o l i o s i s screen-ing i t appears timely to review the r e s u l t s of the program at SFHD. Some evaluation has already been done. Since inception of s c o l i o s i s screening at SFHD there have been yearly reports of the a v a i l a b l e outcomes, how-ever many physicians who received the r e f e r r a l s of screening p o s i t i v e s reported that they would continue to follow the c h i l d but the f i n a l out-come was not reported to the health d i s t r i c t . An estimate of the time spent by s t a f f was made i n a l l years except 1978-79. Some costs were also estimated. Small studies were done i n 1977 and 1978 by the health unit to e s t a b l i s h how the program was received by the community. A public health nurse v i s i t e d a random sample of 31 fa m i l i e s who had a c h i l d screened as p o s i t i v e and the as s i s t a n t medical health o f f i c e r v i s i t e d 10 general p r a c t i t i o n e r s to determine th e i r r e a c t i o n to the program. The general conclusion reached was that the program was we l l received. In the absence of a prospective study i t i s by ascertaining what the outcomes have been from the screening program that the necessary planning decisions can be made now about the future of t h i s program and about expansion of screening to other health d i s t r i c t s . Organization of the Thesis The following chapter w i l l review the l i t e r a t u r e to out l i n e the c r i t e r i a used to evaluate screening programs. Next, the l i t e r a t u r e on 8 s c o l i o s i s and s c o l i o s i s screening w i l l be reviewed to determine how the p r i n c i p a l c r i t e r i a have been met. Chapter three w i l l present the methodology of this study and w i l l include a d e s c r i p t i o n of the program under review and of the data a v a i l -able. The procedure u t i l i z e d to gather a d d i t i o n a l outcome information and to analyse the relevant information w i l l be discussed. In Chapter four the r e s u l t s w i l l be presented i n narrative and tabular form by percentages, rates and use of the f o u r f o l d table. Chapter f i v e w i l l contain discussion of the r e s u l t s i n terms of the c r i t e r i a selected: a c c e p t a b i l i t y of the screening t e s t , accepta-b i l i t y of treatment, v a l i d i t y of the test and a v a i l a b i l i t y or resources. There w i l l be a b r i e f review using the other c r i t e r i a . The concluding chapter w i l l summarize the p o s i t i o n of s c o l i o s i s screening i n terms of the chosen c r i t e r i a and make recommendations about the continuation of the program at SFHD. Suggestions for further study w i l l also be made. D e f i n i t i o n of Terms Used i n This Study A c c e p t a b i l i t y - the extent.to which the volunteer was w i l l i n g to undergo the screening, which can be expressed i n terms of u t i l i z a t i o n , or negatively, as a t t r i t i o n during the program. Bracing - an a p p l i c a t i o n of an orthopedic appliance (orthosis) to correct or maintain a s c o l i o t i c curve. An example would be the Milwaukee brace. Cobb method of curve measurement - the method of measuring the s t r u c t u r a l curve of s c o l i o s i s i n which the upper and lower end vertebrae are f i r s t selected, perpendiculars to t h e i r transverse axes are next erected, then the angle of the curve i s measured at t h e i r point i n t e r s e c t i o n . I t i s the method of measurement advocated by the S c o l i o s i s Research Society. Effectiveness - the c h a r a c t e r i s t i c of a maneuver or treatment doing more good than harm to i n d i v i d u a l s to whom i t i s offered ( e f f i c a c y plus acceptance), the same as usefulness. E f f i c a c y - the c h a r a c t e r i s t i c of a maneuver or treatment doing more good than harm to those who f u l l y comply with the treatment or recom-mendations . E f f i c i e n c y - the a t t r i b u t e of worthwhileness - the best use of resources for the expenditure made. Observation - as i t pertained to an outcome of s c o l i o s i s screening was the process by which the physician who received a r e f e r r a l for possible s c o l i o s i s saw a c h i l d r e g u l a r l y for physical examina-t i o n , with or without radiography. Orthopedic p o s i t i v e - any s c o l i o t i c curve greater than 10° i n i t i a l l y or which reached 11° or more while under observation. Those curves which were l a b e l l e d " s i g n i f i c a n t " or "at r i s k " by an orthopedist w i l l be c a l l e d p o s i t i v e u n t i l X-ray r e s u l t s deter-mine the degree of curvature. P r e d i c t i v e value - the a b i l i t y of a test to give an accurate measure. When given as p o s i t i v e , i t i s the percentage of those i d e n t i f i e d as p o s i t i v e who have the disease, or i f negative, those who are c o r r e c t l y i d e n t i f i e d as disease free. T o t a l p r e d i c t i v e value gives the percentage c o r r e c t l y l a b e l l e d by the t e s t . 10 R e f e r r a l - those ch i l d r e n found with a p o s i t i v e sign of s c o l i o s i s on screening for whom a l e t t e r to the parent was sent advising medical consultation. R e l i a b i l i t y - the a b i l i t y to y i e l d consistent r e s u l t s i n repeated t r i a l s or when administered by d i f f e r e n t screeners. S c o l i o s i s - for the purpose of t h i s study, adolescent i d i o p a t h i c s c o l -i o s i s , described as a l a t e r a l curvature of the spine with r o t a t i o n of the s p i n a l column and r i b s , that i s , with demon-strated s t r u c t u r a l features. Screening - the presumptive i d e n t i f i c a t i o n of unrecognized disease or defect by the a p p l i c a t i o n of te s t s , examinations or other pro-cedures . Screening p o s i t i v e - a c h i l d found to have a sign or signs of s c o l i o s i s . S e n s i t i v i t y - the a b i l i t y of a tes t to c l a s s i f y as p o s i t i v e those per-sons with the disease. S p e c i f i c i t y - the a b i l i t y of a tes t to c l a s s i f y as negative those persons free of the disease. Surgery - i n th i s study any operation performed f o r co r r e c t i o n of a s c o l i o t i c curve, usually s p i n a l f u s i o n with Harrington Rod ins trumentation. V a l i d i t y - the measure of the frequency with which the r e s u l t of a tes t i s confirmed by an acceptable diagnostic procedure. The a b i l i t y of the test to separate those who have the condition from those who do not. CHAPTER TWO REVIEW OF THE LITERATURE This chapter w i l l f i r s t review the l i t e r a t u r e on evaluation of screening programs and second w i l l review what has been written about s c o l i o s i s and screening programs i n respect to these evaluative c r i -t e r i a . Evaluation of Screening Programs Since the 1950's i t has become increasingly popular for medical and public health agencies to i n s t i t u t e screening programs to detect disease at an early, symptomless stage. This discovery of disease i n apparently healthy i n d i v i d u a l s has the purpose of bringing to medical care i n d i v i d u a l s at an e a r l i e r and hopefully more optimal stage of disease for successful treatment. "Successful" implies that there w i l l be less d i s a b i l i t y or premature mortality from the disease when i t i s discovered and treated early i n i t s natural course. Researchers agree that f o r e t h i c a l and economic as w e l l as scien t i f i c reasons c e r t a i n c r i t e r i a or p r i n c i p l e s should be met before screen ing i s i n s t i t u t e d . The following i s a review of the c r i t e r i a , which have been set out as guidelines both before screening i s i n s t i t u t e d and to use i n the continuing evaluation of screening programs i n p r a c t i c e , by the major papers on t h i s subject i n English l i t e r a t u r e . Acheson Reinke (1969) c i t e s the f i v e c r i t e r i a proposed by Acheson i n 1963 to use i n determining which diseases are sui t a b l e for screening. These c r i t e r i a were 1) Each disease should occur f a i r l y frequently in.the popula-t i o n under consideration. 2) A disease should be dangerous to l i f e and cause excessive absence from work and/or d i s a b i l i t y . 3) A s i n g l e sign should carry with i t the high p r o b a b i l i t y that the disease i s present. 4) E l i c i t i n g the sign should be simple -and economical and at the same time unobjectionable to the patient. 5) There should be reasonable prospect that steps can be taken to cure the disease or to prevent i t s progressing once the diagnosis has been made. These c r i t e r i a while u s e f u l lack p r e c i s i o n when they are applied, for example as to what constitutes " f a i r l y frequently" or "excessive absence". More precise c r i t e r i a which incorporated the c r i t e r i a of Acheson were proposed by Wilson and Jungner i n 1968. Wilson and Jungner In a World Health Organization p u b l i c a t i o n ten basic p r i n c i p l e s were enunciated and i t was recommended that these should be met before mass screening was i n s t i t u t e d . 1) The condition should be an important health problem. 2) There should be an accepted treatment for patients with recognized disease. 3) F a c i l i t i e s f o r diagnosis and treatment should be a v a i l a b l e . 4) There should be a recognizable l a t e n t or early symptomatic stage. 13 5) There should be a suitable test or examination. 6) The test should be acceptable to the population. 7) The natural history of this condition, including the devel-opment from latent to declared disease, should be adequately understood. 8) There should be an agreed upon policy on whom to treat as patients. 9) The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced i n r e l a t i o n to possible expenditure on medical care as a whole. 10) Case-finding should be a continuing process and not a "once and for a l l " project. (Wilson and Jungner 1968, pp. 26-27) Wilson and Jungner suggest these principles are guides to plan-ning case-finding so that the main goal of early disease detection, that of finding and treating those with previously unknown disease, while not harming people who are w e l l , i s achieved. When evaluating screening Wilson and Jungner say that two separate but interrelated aspects are considered. F i r s t i s the evaluation of the screening test and second, the evaluation of the r e s u l t s . In both aspects there i s the need for v a standard of c r i t e r i a . McKeown Thomas McKeown (1968) gave two major requirements for screening: the procedure i s effective and i t makes more optimum use of limited resources than the alternatives available. The e t h i c a l differences between screening and normal medical practice were discussed by this writer. He concluded that screening should not be undertaken unless there i s proven medical benefit. The c r i t e r i a to be applied to screen-ing f a l l into two categories accordingly: b i o l o g i c a l and economic. 14 Before a screening measure can be declared sound on b i o l o g i c a l grounds the natural h i s t o r y of the disease must be known, i d e n t i f i c a t i o n must be possible at an early stage of the condition and b e n e f i c i a l methods of treatment must be a v a i l a b l e . For economic j u s t i f i c a t i o n the assur-ance must be given that l i m i t e d resources are better employed with t h i s measure than any competing one. McKeown outlines a scheme f or evaluation of screening procedures. He begins with d e f i n i t i o n of the problem and review of the p o s i t i o n before screening. Next i s review of evidence concerning the screening procedure i t s e l f within two major d i v i s i o n s ; that i s review of the e v i -dence about the effectiveness f i r s t of the diagnostic methods and second, of the proposed treatment. Evidence i s assessed i n terms of ap p l i c a -b i l i t y , error rates, comparison to t r a d i t i o n a l methods, a v a i l a b i l i t y of resources, a c c e p t a b i l i t y and cost. A f t e r the preceding review i s accom-plish e d McKeown suggests that a conclusion could be reached concerning the state of evidence on the problem as a whole. This conclusion would u t i l i z e the evidence on the natural h i s t o r y of the disease and the ef f e c t s of the screening i n terms of both diagnosis and treatment. L a s t l y , there would be comparison of a l t e r n a t i v e approaches to the prob-lem i n terms of medical gains and losses and f i n a n c i a l costs and gains. In conclusion proposals f o r acquiring further evidence and for a p p l i c a -tions of the validated screening procedure complete the evaluation scheme. Cochrane and Holland These writers (1971) r e i t e r a t e d points made by McKeown and emphasized the e t h i c a l consideration i n the introduction of screening programs. The c a l l f o r conclusive evidence that screening could a l t e r 15 the natural h i s t o r y of the condition i n a s i g n i f i c a n t proportion of those screened raised the issue of economic b e n e f i t . What y i e l d from screening makes i t worthwhile? These authors concluded that s c i e n t i f i c and pos-s i b l y f i n a n c i a l j u s t i f i c a t i o n i s required before introducing screening t e s t s . The decision about which diseases j u s t i f y screening rests on evaluation of the test used to detect them. The c r i t e r i a given by Cochrane and Holland for v a l i d a t i n g the test are: 1) S i m p l i c i t y 2) A c c e p t a b i l i t y 3) Accuracy 4) Cost 5) P r e c i s i o n or r e p e a t a b i l i t y 6) S e n s i t i v i t y 7) S p e c i f i c i t y The choice of test w i l l be based on compromise because f u l f i l l m e n t of one condition may be o f f s e t by another. In summary Cochrane and Holland argue that screening procedures are validated by posing two questions: Is the test j u s t i f i e d , s c i e n t i f i c a l l y and f i n a n c i a l l y by the r e s u l t i n g benefit to the community? How e f f i c i e n t i s the proposed te s t as a method of measurement? (Cochrane and Holland 1971) Sackett David Sackett (1975b) adds p r e d i c t i v e power to the seven proper-t i e s of Cochrane and Holland used i n evaluation of a screening measure and emphasizes that the importance given to a p a r t i c u l a r property w i l l vary according to the.purpose of a t e s t . He states that s i m p l i c i t y , a c c e p t a b i l i t y and cost are important i n screening but he gives s e n s i -t i v i t y the most important ranking among properties of a t e s t used for screening because the consequences of missing a case may be " t r a g i c and c o s t l y " (Sackett 1975b). As w e l l as technological requirements as he terms these eight properties, Sackett f e e l s c l i n i c a l and health care requirements must be considered. He poses s i x questions: 1) Are screening maneuvers able to detect disease which i s l i k e l y to have an important impact upon health? 2) W i l l the treatment of r i s k factors have a major impact upon the subsequent development of disease? 3) What are the prospects that patients w i l l comply with thera-peutic regimens i n i t i a t e d as a r e s u l t of screening programs? 4) Do e x i s t i n g screening programs r e a l l y a l t e r the outcomes of the target disease? 5) Are we misled by the t r a d i t i o n a l methods used i n evaluating the c l i n i c a l effectiveness of early detection programs? 6) Have we considered the e n t i r e range of possible e f f e c t s of screening, l a b e l l i n g of i n d i v i d u a l s as diseased and the long-term therapy. (Sackett 1975a, p. 42) These questions were discussed at a meeting of the World Health Organization i n 1971 and translated i n t o seven c r i t e r i a f o r evaluating screening programs: 1) Screening must lead to an improvement i n end-results (defined i n terms of mortality; p h y s i c a l , s o c i a l , and emotional function; pain; and s a t i s f a c t i o n ) among those i n whom early diagnosis i s achieved or i n the other members of the community. a) The therapy for the condition must favorably a l t e r i t s natural h i s t o r y , not simply by advancing.the point i n time at which diagnosis occurs, but by improving sur-v i v a l , function, or both. The modification of " r i s k f a c t o r s " i s not s u f f i c i e n t evidence of effectiveness, nor i s the f a c t that the proposed therapy i s commonly accepted. Claims for therapeutic effectiveness must 17 withstand rigorous methodologic scrutiny, and experi-mental evidence, such as controlled c l i n i c a l t r i a l s , i s a p r e r e q u i s i t e . The measurement of s u r v i v a l and other end-results must withstand epidemiologic and b i o s t a t i s -t i c a l s crutiny. b) A v a i l a b l e health services must be s u f f i c i e n t both to ensure diagnostic confirmation among those whose screen-ing i s p o s i t i v e and to provide long-term care. c) Compliance among asymptomatic patients i n whom an early diagnosis has been achieved must be at a l e v e l to be e f f e c t i v e i n a l t e r i n g the natural h i s t o r y of the disease i n question. d) The long-term b e n e f i c i a l e f f e c t s , i n terms of end-r e s u l t s , must outweigh the long-term detrimental e f f e c t s of the therapeutic regimen u t i l i z e d and the l a b e l i n g of an i n d i v i d u a l as diseased or at high r i s k . 2) The effectiveness of p o t e n t i a l components of multiphasic screening should be demonstrated i n d i v i d u a l l y p r i o r to th e i r combination. 3) If the benefits of screening accrue to the community at large rather than, or i n addition to, the i n d i v i d u a l i d e n t i f i e d (e.g. disease c a r r i e r s , s p e c i f i c occupations), the community be n e f i t claimed must withstand s c i e n t i f i c s c r u t iny. 4) The cost-benefit and cost-effectiveness c h a r a c t e r i s t i c s of mass screening and long-term therapy must be known. This knowledge i s considered e s s e n t i a l i n developing an appro-p r i a t e mix of diagnostic and therapeutic services i n the face of f i n i t e manpower and f i n a n c i a l resources. Therefore, a mechanism for the formal p e r i o d i c weighing of costs against benefits or effectiveness should constitute a basic component of the i n i t i a l screening a c t i v i t i e s . 5) The burden of d i s a b i l i t y for the condition i n question ( i n terms of disease frequency, d i s t r i b u t i o n , s e v e r i t y , and a l t e r n a t i v e approaches to i t s detection and control) must warrant action. 6) The cost, s e n s i t i v i t y , s p e c i f i c i t y , and a c c e p t a b i l i t y of the screening test must be known, and i t should lend i t -s e l f to the u t i l i z a t i o n patterns of the target population. 7) Id e a l l y , an estimate of the s o c i a l b enefit of preventing, a r r e s t i n g , or curing the condition i n question should be known. (Sackett 1975a, pp. 49-50) Sackett (1975b) suggests that when these c r i t e r i a are applied to most preventive screening tests they are performed without evidence 18 as to t h e i r health effectiveness. He comments that by implementation of untested or i n v a l i d programs long-term i l l e f f e c t s may be encountered. There i s damage to the c r e d i b i l i t y of the health professionals, research into a l t e r n a t i v e approaches to detection are discouraged and there i s wastage of resources. Chamberlain Chamberlain (1979) i n h i s approach to evaluation of screening depicts s i x factors which must be considered. These are shown i n Figure 1. The natural h i s t o r y of the disease The v a l i d i t y of the test The effectiveness of treatment The a c c e p t a b i l i t y of screening The a c c e p t a b i l i t y of treatment The a v a i l a b l e health' service resources F i g . 1.—Factors inf l u e n c i n g the effectiveness of a screening programme. SOURCE: J. Chamberlain. Evaluation of Screening Procedures. In The  Theory and P r a c t i c e of Public Health. Edited by W. Hobson. New York: Oxford, 1979, p. 745. 19 Chamberlain believes that the importance of natural h i s t o r y i s foremost. Unless i t i s know what the course of the disease would be without i n t e r -vention, there cannot be evaluation of the maneuver under i n v e s t i g a t i o n . The best way to evaluate the effectiveness of screening and early t r e a t -ment i n a l t e r i n g the natural course of the condition i s by the randomized c l i n i c a l t r i a l . He suggests that these t r i a l s are of necessity long-term because they involve large numbers of people i n the case of the chronic, low prevalence diseases for which screening i s suggested. The a c c e p t a b i l i t y of treatment must be considered i n the evaluation of a preventive measure. Unless there i s compliance with the recommended therapy then there i s l i t t l e point i n detecting the condition - indeed there may be a disadvantage i n terms of anxiety and increased absenteeism. The v a l i d i t y of the screening test i s measured by s e n s i t i v i t y and spe-c i f i c i t y . I t i s obvious that a screening test i s not s a t i s f a c t o r y i f i t allows a large number of diseased people to s l i p through or i f i t i n c o r r e c t l y labels as diseased those i n d i v i d u a l s who are r e a l l y w e l l . The screening test.must be acceptable to the people at r i s k of the d i s -ease or resources w i l l be wasted. The l a s t f a c t o r , a v a i l a b i l i t y of resources, must be considered i n evaluating screening because i t i s pointless to begin a screening program without the capacity both to carry out the program and to do further diagnostic tests and treatment as required. Chamberlain emphasizes the importance of the administrator having as complete information as possible so that the best possible decisions can be made about the a l l o c a t i o n of scarce resources i n an attempt to c o n t r o l an important disease by means of screening programs. Because the e f f e c t s of screening are dependent on what can be done to improve prognosis by treatment, Chamberlain stresses that a research p r i o r i t y should be the study and development of e f f e c t i v e therapies. Pe r i o d i c Health Examination Report In 1980 a f e d e r a l l y appointed Task Force on the P e r i o d i c Health Examination reported i t s findings a f t e r reviewing 100 p o t e n t i a l l y pre-ventable conditions. The d e c i s i o n was made as to whether the condition was t r u l y preventable a f t e r judging i t according to a standard which applied three sets of c r i t e r i a . The f i r s t set of c r i t e r i a judged the effectiveness of the a v a i l -able treatment or preventive measure. To measure effectiveness the question was asked: Does the a v a i l a b l e treatment, preventive or thera-peutic, i n s t i t u t e d as a r e s u l t of carrying out the periodic health examination, do more good than harm to those patients to whom i t i s offered? The Task Force i d e n t i f i e d three grades of v a l i d i t y . In l e v e l I, effectiveness was demonstrated i n a randomized c l i n i c a l t r i a l . In l e v e l I I , either a well-designed cohort or case-control study or com-parison between times and places with and without treatment, would show that treatment or prevention does more good than harm. The t h i r d l e v e l of v a l i d i t y was based on the opinion of respected a u t h o r i t i e s who used d e s c r i p t i v e studies, c l i n i c a l experience or reports for t h e i r informa-t i o n . The second set of c r i t e r i a judged the current burden of poten-t i a l l y ameliorable s u f f e r i n g . Two aspects were considered: the impact on the i n d i v i d u a l and the impact on society. For the i n d i v i d u a l , 21 measures such as l i f e years l o s t , morbidity i n terms of h o s p i t a l days, pain, and treatment costs were indicators of impact. The impact on society was determined by indi c a t o r s such as mortality, morbidity and costs of treatment. The t h i r d and l a s t set of c r i t e r i a f o r judging whether the con-d i t i o n was p o t e n t i a l l y preventable applied to the maneuver undertaken to f i n d or prevent the condition. Aspects considered i n applying these c r i t e r i a were the benefits and r i s k s ; the s e n s i t i v i t y , s p e c i f i c i t y and pr e d i c t i v e value; and the safety, s i m p l i c i t y , a c c e p t a b i l i t y to patients and cost. Following assessment of evidence using these three sets of c r i -t e r i a , prevention of the condition would receive one of f i v e classes of recommendation. These recommendations were l a b e l l e d A to E according to the strength of the evidence to include screening for the condition i n a pe r i o d i c health examination (A) or to excluding i t (E). Category C, i n which s c o l i o s i s was placed, stated that there i s poor evidence fo r i n c l u s i o n or exclusion of the condit ion i n the periodic health examination and posed the most d i f f i c u l t y for the committee. The com-mittee suggested i n cases of inadequate evidence i t was better to err on the side of prudence and not include the condition i n a per i o d i c health examination. Summary of C r i t e r i a Reviewing the c r i t e r i a presented i t i s obvious that there i s general agreement on a core of c r i t e r i a . I t i s basic that screening must make a di f f e r e n c e , and a p o s i t i v e d i f f e r e n c e , that i s , i t must do 22 more good than harm. To know that i s happening, the course of the disease must be understood. The test i t s e l f must be v a l i d and accep-table to the c l i e n t . E f f e c t i v e treatment which i s acceptable must be possible and the resources for diagnosis and treatment a v a i l a b l e . A f t e r these c r i t e r i a are met, economical review should show that screening f o r the p a r t i c u l a r disease represents a worthwhile use of f i n i t e resources compared to other a l t e r n a t i v e uses. Underlying a l l c r i t e r i a i s the premise that the evidence presented to meet the c r i t e r i a has been derived s c i e n t i f i c a l l y , preferably using experimental or at l e a s t quasi-experi-mental methodology. This completes the review of c r i t e r i a proposed for evaluation of screening. In the next section the l i t e r a t u r e on s c o l i o s i s and i t s screening programs are examined to determine how these c r i t e r i a have been f i l l e d . Evaluation C r i t e r i a Applied to S c o l i o s i s  and S c o l i o s i s Screening While there has been a great deal written about s c o l i o s i s and act i v e encouragement by the S c o l i o s i s Research Society for screening programs to be included i n school health programs, evaluative studies on the e f f i c a c y and effectiveness of t h i s screening are rare. Wingate aft e r a l i t e r a t u r e search concluded that "to date, no c r i t i c a l evalua-tions have been performed on any published s c o l i o s i s programs" (1977, p. 73). The r a t i o n a l e for introduction of screening programs i s the reportedly high prevalence rates of s c o l i o s i s and the benefit of early treatment. No v a l i d a t i o n of the test procedure, nor any estimates of the costs, benefits or effectiveness had been reported at the time of Wingate's p u b l i c a t i o n . 23 Howell (1978) i n Edmonton and Williams and Tice (1980) i n Ontario have presented research findings i n recent years which attempt to e v a l -uate screening programs i n place i n those provinces. They c a l l a t tention to several concerns about the effectiveness of s c o l i o s i s screening of school c h i l d r e n i n t h e i r j u r i s d i c t i o n s with p a r t i c u l a r concern about the r e l i a b i l i t y and v a l i d i t y of the screening t e s t . To u t i l i z e c r i t e r i a f o r evaluation of s c o l i o s i s screening pro-grams as described i n the l i t e r a t u r e i t appears u s e f u l to begin with the ten c r i t e r i a defined by Wilson and Jungner i n 1968. V e r r i e r et a l . (1979) and Wingate (1977) have also u t i l i z e d t h i s framework. Two addi-t i o n a l c r i t e r i a have been selected from the 1971 WHO statement on screening (Sackett 1975a) so that twelve c r i t e r i a i n a l l w i l l be u t i -l i z e d . 1. The condition should be an important health problem Although s c o l i o s i s has been known f o r centuries the question for consideration now i s - how s i g n i f i c a n t i s s c o l i o s i s ? Of p a r t i c u l a r concern i s the importance of adolescent i d i o p a t h i c s c o l i o s i s which has been the target of SFHD's screening program. To evaluate importance the prevalence and e f f e c t s of the disease w i l l be discussed. Prevalence Moe et a l . (1978) suggest that prevalence i s determined by mass screening techniques applied to large unselected population groups. S c o l i o s i s prevalence information i s a v a i l a b l e from two major sources. The f i r s t i s based on chest X-rays taken for tuberculosis screening and the second from school screening programs. 24 TB X-rays provided early information on the prevalence of s c o l -i o s i s . In a study of 50,000 minifilms taken i n TB surveys, i n those over 14 years of age s c o l i o s i s curves of 10° or more were noted i n 1.9 percent and curves of 20° or more i n 0.5 percent (Shands and Eisberg 1955). Other studies report prevalence of 1.1 percent and 0.47 percent (Moe et a l . 1978) r e s p e c t i v e l y . The disadvantages of data from chest minifilms are the small s i z e of the f i l m , underpenetration of the spine and the f a c t that v i s u a l i z a t i o n of the lumbar spine i s not included. School screening programs have provided data since programs began, i n the state of Delaware i n 1962. While prevalence studies vary there i s general agreement that curves 11° or greater are present i n 2 percent to 4 percent of young adolescents (Brooks 1980; Hornung 1977; Howell et a l . 1980; Kane:.1977a;-."Moe et a l . 1978; Rogali et a l . 1978). Lonstein (1977) reviewed 23 prevalence studies from 1957 to 1976 which included over a m i l l i o n subjects from around the world. He reported that while there was some v a r i a b i l i t y i n ages screened and c r i t e r i a for recording a p o s i t i v e , the prevalence rate generally f e l l between 2.5 percent and 4 percent. Kane (1977b) comments on the danger of the overstated case i n regards to published prevalence figures from s c o l i o s i s screening studies. He notes the consistency of figures improves as the severity of curve increases. He suggests that a curve can be drawn based on a log normal d i s t r i b u t i o n (the natural log of the number of degrees of a curvature i s normally d i s t r i b u t e d ) . From t h i s curve prevalence figures of 0.5 percent for 20° or greater curves, 0.2 percent for 30° or greater and 0.1 percent for 40° curves can be estimated. Kane suggests that by 25 using two c r i t e r i a , f i r s t , that s c o l i o s i s of 20° i n an immature person should be treated and second, that any immature i n d i v i d u a l with a curve over 10° should be followed, that the adolescent s c o l i o s i s population i s 2.5 percent. Of the population screened for s c o l i o s i s there appears to be consensus on the prevalence of treatable curves. Rogala et a l . (1978) suggests 0.275 percent and Lonstein (1977) 0.3 percent. The Health Surveillance Registry can provide prevalence figures for s c o l i o s i s by age-group and sex for B r i t i s h Columbia but i t i s acknowledged that there has not been comprehensive reporting so that the f i g u r e s do not r e f l e c t the true prevalence of s c o l i o s i s ( C o l l s 1981). Prevalence by sex has been studied extensively. O r i g i n a l l y s c o l i o s i s was f e l t to be f a r more prevalent i n females but the occur-rence of minor curves i s d i s t r i b u t e d i n a female to male r a t i o of 1.5:1 (Lonstein 1977) or 1.24:1 (Rogala et a l . 1978). Rogala found the r a t i o varied with the severity of the curve; 1:1 for curves 6° to 10° and up to 5.4:1 for curves over 20°. The r a t i o was 7:1 for curves under t r e a t -ment. Keim (1978) reports a 7:1 incidence of persistent curves. In the only study reporting prevalence by r a c i a l group S e g i l i n Johannesburg, South A f r i c a found 2.5 percent of the Caucasians had curves of 10° or more (N = 929) and Africans (N = 1016) had a prevalence of 0.03 percent (Lonstein 1977). There appears to be a f a m i l i a l tendency for s c o l i o s i s to occur. Rogala found a p o s i t i v e family h i s t o r y i n 19 percent of the subjects i n a study c a r r i e d out by himself and others i n 1978. In summary i t could be stated that s c o l i o s i s i s a disease of low prevalence and that females with a family h i s t o r y of s c o l i o s i s are the most at r i s k f o r s i g n i f i c a n t curves. 26 E f f e c t s of s c o l i o s i s The curvature of the spine i n s c o l i o s i s may be non-progressive but those few curves which progress can have serious e f f e c t s (Kane 1978). The developing curvature i s accompanied by s p i n a l column r o t a -t i o n causing fanning of the r i b s on one side and inward compression on the other. This d i s t o r t i o n r e s u l t s i n cramping of the heart and lungs. Less mobility of the spine and a d i s f i g u r i n g r i b hump are other untoward e f f e c t s . While there are many studies of the prevalence of s c o l i o s i s i n the adolescent population there i s a lack of studies i n d i c a t i n g the population prevalence of severe symptomatic s c o l i o s i s . Studies which document the death, d i s a b i l i t y , d i s r u p t i o n , discontent and d i s s a t i s -f a c t i o n due to s c o l i o s i s are rare. While i t may be u s e f u l to note that about 2 percent of an early adolescent group have curves greater than 10°, to consider the importance of s c o l i o s i s further information i s v i t a l . S t a t i s t i c s c i t i n g s c o l i o s i s as a cause of death are a v a i l a b l e from S t a t i s t i c s Canada and are presented i n Table I. Kyphoscoliotic heart disease which was mentioned by Nachemson (1968) as a leading cause of death i n s c o l i o t i c s , claimed no l i v e s i n B.C. in. 1979. and. caused only three deaths i n Canada. Limited information i s a v a i l a b l e from case studies which report the long-term e f f e c t s of progressive s c o l i o t i c curves. I t has been on the basis of these retrospective studies that the importance of preven-t i o n of s c o l i o s i s has been based. TABLE I DEATHS DUE TO SCOLIOSIS* AND DUE TO ALL CAUSES, B.C. AND CANADA, 1972-1978 M F B.C. Total S c o l i o s i s Total a l l causes M F CANADA Tota l : S c o l i o s i s T o t a l a l l causes 1972 0 0 0 18021 0 3 3 162413 1973 0 1 1 18095 1 4 5 164039 1974 0 0 0 19177 0 1 1 166794 1975 0 1 1 19151 0 3 3 167404 1976 0 0 0 18788 1 3 4 167009 1977 0 0 0 18596 1 4 5 167498 1978 0 0 0 19058 2 1 3 168945 *ICD code 735.0 SOURCE: Suzanne Draper, Inquiries O f f i c e r , S t a t i s t i c s Canada (Personal Communication, Aug. 12, 1981) Vancouver, B.C. In a b r i e f report of a study by Drummond et a l . (1976) long-term e f f e c t s of untreated s c o l i o s i s were c i t e d . Back pain was reported by 40 percent of the patients and t h i s was constant i n 24 percent of the sample. In t h i s study group: 24 percent were unemployed, 15 per-cent had never worked, 69 percent were embarrassed by th e i r appearance and 20% avoided s o c i a l contact. T h i r t y percent of the men and 42 per-cent of the women were unmarried. The sample was of 55 adults from an unselected ser i e s of 107 patients seen as c h i l d r e n i n three Quebec h o s p i t a l s . The degree of curvature however i s not reported. Further descriptions of persons with untreated s c o l i o s i s from retr o s p e c t i v e studies are reported under c r i t e r i a seven, concerning the natural h i s t o r y . The reported p h y s i c a l and s o c i a l e f f e c t s of untreated progressive s c o l i o s i s would .appear to i n d i c a t e a serious health problem i n those persons affected with severe disease but i n f o r -mation i s lacking r e l a t i n g degree of curvature to e f f e c t s and to pre-valence i n the population. Statements that s c o l i o s i s i s an important health problem must be considered as presumptive. 2. There should be accepted treatment for patients with recognized  disease Wilson and Jungner c a l l t h i s the most important c r i t e r i o n because i t i s of paramount importance to treat the condition adequately when i t i s discovered. In the sense that "accepted" i s used i n t h i s c r i t e r i o n other w r i t e r s , such as Chamberlain and Sackett, use the term " e f f e c t i v e " . E f f e c t i v e implies e f f i c a c y , that i s , that the treatment does more good than harm i n those r e c e i v i n g i t . Sackett suggests as w e l l as e f f i c a c y , effectiveness includes acceptance of the treatment by those to whom i t i s offered while Chamberlain l i s t s a c c e p t a b i l i t y as a separate c r i t e r i a . Both e f f i c a c y and a c c e p t a b i l i t y of the recognized treatments for s c o l i o s i s w i l l be discussed under t h i s c r i t e r i a . The S c o l i o s i s Research Society has published a Physician's Handbook of Spinal Screening and Treatment which contains the recom-mended treatment for s c o l i o s i s i n three major categories: c o n t r o l l e d observation, bracing and surgery. Controlled observation includes periodic c l i n i c a l examinations with standing X-rays of the spine as necessary throughout the years of growth to determine progression of a curve. Keim (1978) states that only two treatments, s p i n a l bracing and surgery e f f e c t i v e l y correct s c o l i o s i s . These treatments w i l l be considered i n terms of e f f i c a c y and a c c e p t a b i l i t y as the components of effectiveness using what i s described i n the l i t e r a t u r e . There are d i f f i c u l t i e s i n l o c a t i n g conclusive evidence of the e f f i c a c y of treatment of s c o l i o s i s . One problem l i e s i n the deter-mination of differences i n outcome due to early diagnosis and treatment of s c o l i o s i s wheir there i s lack of knowledge about the n a t u r a l .history of the disease, that i s , which curves w i l l progress. As mentioned pre-v i o u s l y some curves can even spontaneously improve (Brooks 1977; Rogala et a l . 1978). Other d i f f i c u l t i e s occur because there may be d i s c r e -pancies i n measuring curves. Rogala et a l . (1978) found that any curve can be shown to vary up to 5° with d i f f e r e n t examinations. The proposed treatment for s c o l i o s i s w i l l be considered by examining evidence as to the effectiveness of non-operative and oper-a t i v e approaches. 30 Non-operative approaches Exercises are mentioned as treatment by Keim (1978) so that he could strongly condemn them as a sole cure for s c o l i o s i s . He r e j e c t s the p r a c t i c e of detecting a patient early and pre s c r i b i n g an exercise program and thus l o s i n g the patient to follow-up u n t i l the curve i s severe. In a study reported by Stone et a l . (1979) i t was concluded that exercise had no e f f e c t on change i n curvature of 42 patients with minimal i d i o p a t h i c s c o l i o s i s (defined as less than 20°). James (1976) reports on a 1941 study of several thousand cases treated by exercise. The conclusion was that exercises were demon-st r a b l y i n e f f e c t i v e i n c o n t r o l l i n g a curve's d e t e r i o r a t i o n or i n improving curves already present. Brooks (1980) reports on a study of 42 adolescents with minimal i d i o p a t h i c curves given an exercise regime. No s i g n i f i c a n t improvement was found i n comparing the study group with a control group during the 9 to 15 month study period. Bracing to treat s c o l i o t i c curves i s usually accomplished with the Milwaukee brace. I t i s recommended i n general for progressive f l e x i b l e curvature of 20° to 40° i n growing children. The main purpose of the brace i s to prevent progress of the curve with the secondary aim of improving the curve (Moe et a l . 1978). The length of treatment with the brace averages three years. X-rays may be taken three or more times yearly. Response to the brace i s v a r i a b l e and unpredictable, therefore monitoring the curve i s e s s e n t i a l . I t must not be worn by patients whose curves progress while they are wearing i t . Several studies have .been done which give end-result evaluations a year or so a f t e r completion of the brace program. One such study by Edmonson and Morris (1977) considered a group of 52 patients followed for more than s i x months and an average of 22 months a f t e r cessation of brace wearing. The conclusion reached was that the improvement accomplished i n bracing was not as great as for surgery however pro-gression of curves under 60° was usually halted. Although improvement i n some curves did occur t h i s gradually was l o s t a f t e r treatment ceased. A study of long term r e s u l t s was c a r r i e d out by Mellencamp et a l . (1977) of 47 patients completing treatment of at l e a s t f i v e years with the Milwaukee brace. There was 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 var-i a t i o n when the r e s u l t s were analysed according to age, s i z e of i n i t i a l curve or l o c a t i o n of curve. One-third of patients l o s t 5° of t h e i r c o r r e c t i o n . The other two-thirds had curves which progressed. The range was from a gain of 40° to a loss of 26°. The most important findings of t h i s study were that there was extreme v a r i a b i l i t y i n the age at which curves s t a b l i z e d or at which correction occurred and var-i a t i o n i n the end-results. The main d e f i c i t was that neither of these studies were randomized c l i n i c a l t r i a l s of bracing. Blount (1981) emphasizes the importance of using the Milwaukee brace only i n curves occurring i n immature g i r l s so that vertebrae may be reshaped with growth. The brace may correct curves i n those near s k e l e t a l maturity but the spine w i l l not maintain the correction and w i l l return to the o r i g i n a l curve. The crux i s whether t h i s i s an acceptable curve. I f i t i s not, then surgery should be the o r i g i n a l choice. In evaluation of e f f i c a c y of bracing i t would be important to know i f bracing were applied only to those curves meeting the c r i t e r i a of immaturity or i f the sample was unselected as to bone age. 32 A randomized c l i n i c a l t r i a l of the Milwaukee brace has not been done. I t might be considered unethical at t h i s point i n time because of the general b e l i e f by orthopedic surgeons using the technique that i t i s b e n e f i c i a l but the only evidence a v a i l a b l e as to i t s e f f i c a c y i s from end-results of c h i l d r e n i n bracing programs and these r e s u l t s are equivocal. In searching the l i t e r a t u r e for evidence of the a c c e p t a b i l i t y of bracing there were l i m i t e d reports a v a i l a b l e . Wickers (1977) states that the Milwaukee brace may be rejected by some adolescents despite i t s s u i t a b i l i t y for treatment of t h e i r condition. Concern about looking d i f f e r e n t , being less mobile and having to wear camouflaging cl o t h i n g have been c i t e d as reasons for r e f u s a l to wear the brace. Moe and Kettleson (1970) report 20 percent of t h e i r patients refused to wear their braces. One-third of brace patients required intervention to overcome psychological d i f f i c u l t i e s i n adjusting to brace treatment (Heckman-Schatzinger et a l . 1977). Gurr (1977) reports r e f u s a l s over a two year period of 4 of 75 c h i l d r e n who had braces prescribed. Operative approaches Surgery i s needed for those cases not manageable by bracing or f o r large i n f l e x i b l e curves. There appears to be general agreement that curves over 50° require surgery, curves from 40° to 50° may require operative treatment and those under 30° can be dealt with more conservatively. These recommendations appear quite uniformly i n the l i t e r a t u r e (James 1976; Moe et a l . 1978) and i n d i r e c t communication with orthopedic surgeons (Tredwell 1981). 33 The s u r g i c a l approach to treatment for s c o l i o s i s i s usually by Harrington Instrumentation with fusion. Moe et a l . (1978) state that s u r g i c a l treatment i s safe i n good hands, while James (1976) suggests that c o r r e c t i o n ( i . e . traction) followed by fusion of the spine i s the basic treatment method for s c o l i o s i s except for s l i g h t curves manage-able by bracing. Evidence of the effectiveness of surgery has been reported by Goldstein (1969) but a pseudarthrosis rate of 5 percent occurred (4 of 80). In the 76 patients with s o l i d fusion post-operative loss of cor-r e c t i o n averaged 7° or l e s s . Ponder (1975) with an e a r l i e r m o b i l i z a t i o n approach averaged a loss of 5.3° i n curve correction and a pseudar-throsis rate of 5 percent. Other complications occurring are i n f e c t i o n and neurological damage. A study by the American S c o l i o s i s Research Society quotes an incidence of 0.7 percent for the l a t t e r . The mor-t a l i t y rate has been reported v a r i o u s l y as 6 percent, 0.07 percent and 1.4 percent (Ponder 1975). Edgar (1980) reported a 15° average curve d e t e r i o r a t i o n post-operatively i n adolescents between fusion and maturity. D e t e r i o r a t i o n i n adult l i f e averaged 2°. Acceptance of the recommendation for surgery was not documented i n the l i t e r a t u r e but one can surmise some reluctance to have a c h i l d undergo major surgery with post-operative incapacity for several months when the c h i l d may have been symptomless and appear normal to the parents. Acceptance of i n i t i a l r e f e r r a l Before leaving the aspect of a c c e p t a b i l i t y of the treatment, there i s another l e v e l of a c c e p t a b i l i t y p r i o r to either bracing or 34 surgery and that i s the acceptance of the i n i t i a l r e f e r r a l for medical assessment a f t e r screening has determined a possible s c o l i o s i s curve. Brooks et a l . (1975) found among a group of 374 patients being observed a f t e r a screening program that 25.9 percent refused further evaluation or were l o s t to follow-up. In an Ontario study i n 1977, 827 c h i l d r e n were ref e r r e d f or medical follow-up a f t e r screening and there was no evidence of a completed r e f e r r a l i n 20 percent of the cases (Williams and Tice 1980). In a North Vancouver study only 2 of 307 r e f e r r a l s f a i l e d to comply with r e f e r r a l (North Shore Health Department 1981). To complete consideration of t h i s c r i t e r i o n mention should be made of the conclusion of the Task Force on the P e r i o d i c Health Exam-in a t i o n (1980) that e f f i c a c y of treatment was d i f f i c u l t to determine because of the incompleteness of follow-up data and the fa c t that improvement could occur without treatment. Evidence presented on methods of treatment such as the Milwaukee brace are not acceptable because none are based on case-control or even quasi-experimental study design. While surgery prevents the deformity from progressing i t has an accompanying mortality and morbidity. In t h i s Task Force report the effectiveness of prevention/treatment i s given as "unknown". 3. F a c i l i t i e s f o r diagnosis and treatment should be a v a i l a b l e Wingate (1977) and Frost (1978) discuss diagnostic and t r e a t -ment f a c i l i t i e s which are necessary before introduction of s c o l i o s i s screening programs. In planning f o r the implementation of statewide screening i n Hawaii, Frost (1978) considered the a v a i l a b i l i t y of personnel, equip-ment and supplies and community resources before screening would com-mence. The number of orthopedic s p e c i a l i s t s , p a r t i c u l a r l y those s p e c i a l i z i n g i n s c o l i o s i s , and of c l i n i c f a c i l i t i e s (including v i s i t i n g c l i n i c s to other areas) were a l l reviewed. No mention was made of r a d i o l o g i c a l services or o r t h o t i c (bracing) resources. Wingate (1977) stressed the importance of consideration of a v a i l a b l e diagnostic and treatment f a c i l i t i e s when introducing s c o l -i o s i s screening i n an urban s e t t i n g . She mentions that s p i n a l X-rays must be possible and r e f e r r a l centres a l e r t e d to the possible i n f l u x . Here also no mention i s made of brace service or orthopedists but t h i s may be considered part of the c l i n i c resources. Taylor et a l . (1978b) suggest that a school screening program for s c o l i o s i s should not commence without consideration of a v a i l a b l e diagnostic and treatment services. They found that i n A u s t r a l i a there were d e f i c i t s i n the number of orthopedic surgeons a v a i l a b l e and i n the state of development of o r t h o t i c s . They also suggest i n s t i t u t i o n of screening without considering a v a i l a b l e treatment could create a dilemma caused by anxious parents and c h i l d r e n , long waits for appointments nec e s s i t a t i n g involved t r a v e l and inadequate brace maintenance. The conclusion: that while screening programs could under the r i g h t con-d i t i o n s be an admirable addition to public health services they should only be introduced under the prime medical guidelines "the r i g h t thing, for the r i g h t reasons, at the r i g h t time" (Taylor et a l . 1978b, p. 3). In the large school screening programs begun i n Montreal i n 1974 the resources which were coordinated as i n t e g r a l parts of the program included the community health department, school nurses and h o s p i t a l medical centre services such as the medical consultant, rad-iology, physiotherapy and o r t h o t i s t . Administrative services f o r records and data c o l l e c t i o n and the bus company were other services included i n the "team" which was managed by a program coordinator (Gurr 1977). I t i s generally agreed that before screening begins personnel should be a v a i l a b l e to carry out screening and that diagnostic and treatment f a c i l i t i e s should be capable of absorbing r e f e r r a l s from the screening program. 4. There should be a recognizable l a t e n t or early symptomatic stage In the early or p r e c l i n i c a l stages of s c o l i o s i s there i s no pain or other symptoms, but c e r t a i n signs do occur which may be i n d i -c a t i v e of pathology. These early signs include v i s i b l e f i x e d r o t a t i o n on forward bending (the c l a s s i c r i b hump), scapular prominence, unequal shoulder l e v e l , unequal waist angles, p e l v i c o b l i q u i t y as evidenced by i l i a c c r e s t l e v e l and plumb bob misalignment (Keim 1978; Hoe et. a l . 1978). It i s agreed that there i s a stage of s c o l i o s i s when an early curve may be detected but i t i s d i f f i c u l t to determine which of these early curves are s i g n i f i c a n t , that i s , which are minor non-progressive curves not r e q u i r i n g continuing management and those which w i l l become progressive severe s t r u c t u r a l deformities. This aspect of s c o l i o s i s w i l l be discussed i n more d e t a i l under c r i t e r i o n seven - the natural h i s t o r y . 37 5. There should be a s u i t a b l e test or examination Description of the tests The commonly recognized screening test for s c o l i o s i s i s des-cribed i n the Screening Handbook of the S c o l i o s i s Research Society, as a forward bending t e s t , with the feet together, cl o t h i n g removed to the hips, i n which the examiner observes the spine i n upright and f o r -ward bending p o s i t i o n s . There i s another less common method of screen-ing using photogrammetry c a l l e d the Moire t e s t . The subject i s p o s i -tioned i n front of a screen of f i n e wires. A l i g h t i s projected through the screen and shadows from the wires ou t l i n e the contours of the sub-j e c t ' s back. A photograph i s taken and studied for asymmetrical pat-terns (Howell et a l . 1978). The s u i t a b i l i t y of the Moire test w i l l be reviewed a f t e r the standard t e s t . The c r i t e r i a f o r a screening test have been discussed previously (Cochrane and Holland 1971, Sackett 1975b) and selected ones are applied to the s c o l i o s i s screening test as follows: S i m p l i c i t y The test i s easy to understand and r i b humps of marked degree are obvious. No expensive equipment i s required i n te s t i n g . Lonstein (1977) suggests the test can be done by school nurses or ph y s i c a l educa-t i o n teachers and a large group processed r a p i d l y and e a s i l y "a 30 second investment for a l i f e t i m e of dividends". V a l i d i t y Wingate (1977) as w e l l as Howell and Craig (1980) give v a l i d i t y as the key c r i t e r i o n f o r a t e s t . V a l i d i t y can be measured i n terms of the s e n s i t i v i t y , s p e c i f i c i t y , (or f a l s e p o s i t i v e and f a l s e negative rates) as w e l l as by the p r e d i c t i v e value. Howell and Craig (1980) suggest that the p r e d i c t i v e value of a p o s i t i v e t e s t (PVPT) i s the best indicator of v a l i d i t y of a screening t e s t . In a study assessing physician screeners Howell et a l . (1980b) found a PVPT range of 7 per-cent to 30 percent f o r curves equal or greater than 15° and 31 percent to 54 percent f o r curves equal or greater than 10°. Comparing nurses and physicians i n v a l i d i t y of screening decisions, the following i s reported: f o r curves equal to or greater than 10° - nurses' s e n s i t i v -i t y 71 percent, s p e c i f i c i t y 36 percent, physicians' s e n s i t i v i t y 81 percent, specif icity-'22 percent, while for curves equal to or greater than 15° - nurses' s e n s i t i v i t y 76 percent, s p e c i f i c i t y 35 percent, physicians' s e n s i t i v i t y 81 percent, s p e c i f i c i t y 21 percent. V e r r i e r et a l . (1979) assessed the v a l i d i t y of the screening te s t i n a t r i a l i n Etobicoke, Ontario and found that i n a sample of 60 c h i l d r e n seeded with 16 confirmed s c o l i o t i c s who were screened by pub-l i c health nurses, physiotherapists, a physician and by photographers, only one c h i l d was found free of s c o l i o s i s by a l l screeners and only two were found p o s i t i v e by a l l examiners. Over a l l there was 60 percent i n t e r - r a t e r agreement. In t h i s study to eliminate the p o s s i b i l i t y of poor t r a i n i n g of the rat e r s i n use of the screening t e s t , a d d i t i o n a l t r a i n i n g was given to a l l raters with no s i g n i f i c a n t improvement i n a second screening experience. In completion of a f o u r f o l d table V e r r i e r found s e n s i t i v i t y 77 percent, s p e c i f i c i t y 40 percent, and PVPT 35 percent. Ove r a l l v a l i d i t y as determined by the number of c h i l d r e n accurately c l a s s i f i e d was 51 percent. These researchers concluded on the basis of these r e s u l t s that the r e l i a b i l i t y and v a l i d i t y of the t e s t for s c o l i o s i s was ques-tionable. Repeatability This can be assessed by measuring i n t e r r a t e r , intermethod and i n t r a r a t e r agreements. V e r r i e r et a l . (1979) report on a l l three i n t h e i r study i n Ontario. I t was reported that raters agreed with them-selves an average of 61 percent of the time. Overall average of i n t e r r a t e r agreement was 69 percent (standard deviation of 11 percent). Intermethod agreement (using Moire photograph) was 59 percent o v e r a l l . A l l r a t e r s (physiotherapists, nurses, physicians) were found equally l i k e l y to make errors. Cost Direct cost of screening i t s e l f i s generally agreed to be acceptable because of the use of volunteers and a v a i l a b l e personnel; however the i n d i r e c t costs are not always included, i . e . X-rays, physi cians and s p e c i a l i s t s . In view of the high f a l s e p o s i t i v e rate these costs are s i g n i f i c a n t . Moe reports on cost accounting and gives cost of screening as $1684 per 400 students screened. He suggests without early detection, assuming one c h i l d i n 400 required surgery the cost would be $5500 (Moe et a l . 1978). Williams and Tice (1980) remind readers that besides cost of screening and medical follow-up i n d i r e c t costs - for time l o s t , anxiety and fear - must be accounted f o r . In summary the standard screening test appears to meet the c r i t e r i a of a s u i t a b l e test on the grounds of s i m p l i c i t y and d i r e c t costs 40 but evidence on validity and repeatability raises concerns as do the indirect costs generated by screening. Moire test The c r i t e r i a of simplicity, validity, repeatability and cost w i l l be considered briefly in relation to the Moire test as reported in the literature. There have been several studies u t i l i z i n g photogrammetry along with c l i n i c a l screening (Howell et a l . 1978; Howell and Craig 1980; Howell et al. 1980). This technique involves use of heavy equipment which requires transportation. D i f f i c u l t i e s positioning subjects have been noted (Howell et a l . 1980). Seventy-one percent of curves of 10° or more went undetected (Howell et a l . 1978). Verrier et a l . (1979) in a study to compare Moire topography and physical examination found an unacceptably low rate of r e l i a b i l i t y and validity with an unaccep-tably high level of false positives and negatives. Because of those unacceptable findings use of the Moire test i s s t i l l in the experimental state. The reduction of expensive time required to screen large numbers of children was anticipated to be an advantage of this method (Howell et a l . 1980). This possibility keeps interest in i t s development high. It appears the Moire test f a i l s to meet the c r i t e r i a of a simple, valid, reliable test and the question on cost i s s t i l l unanswered. 6. The test should be acceptable to the population Stangler et a l . (1980) proposes that a l l who w i l l be affected by a screening test should find i t acceptable. This includes families, children, the professionals who receive the referrals and the whole community. 41 In some areas where a signed parental consent was required before screening 85 percent to 90 percent were returned (Williams and Tice 1980). These same investigators suggest that questions could be added to the consent form to determine i f previous h i s t o r y of back problems was a reason f o r r e f u s a l to consent to screening. In other areas a consent form along with an explanatory l e t t e r was used (Howell et a l . 1978). The form was to be returned only i f there was objection to screening. They report t h i s a highly acceptable method. The North Vancouver Health Department also uses the dissent method of consent (1981). During a s c o l i o s i s screening p i l o t project i n Hawaii i n v o l v i n g 875 c h i l d r e n there were 24 parent r e f u s a l s (3 percent) and 18 student r e f u s a l s (2 percent) (Frost 1978). Howell and Craig (1980) recommend from th e i r Edmonton experience where a l l grade seven g i r l s are screened, that because adolescent g i r l s are e a s i l y perturbed by the program i t should be de-emphasized. They accomplish t h i s by having the regular school nurse do screening as part of grade seven p e r i o d i c examinations. Wingate (1977) found that undres-sing and semi-nudity caused some embarrassment but i n general the test was acceptable. A c c e p t a b i l i t y of the Moire test was only 70 percent to 80 per-cent i n one Ottawa study, because parents misunderstood the test and . assumed r a d i a t i o n was involved (Columbian A p r i l 7, 1979). Another con-cern expressed was the lack of privacy because the buttocks were exposed and the embarrassment caused by the presence of a young male technician. Physician, acceptance Another recommendation from the study of Williams and Tice (1980) was that physicians i n Scarborough be surveyed to determine t h e i r views on the screening program and. c r i t e r i a for diagnosis and management. The survey could i d e n t i f y physician acceptance of the program. There appears to be arrange of a c c e p t a b i l i t y of s c o l i o s i s screening reported i n the l i t e r a t u r e of from 70 percent to 95 percent. 7. The natural h i s t o r y of t h i s condition including the development  from l a t e n t to declared disease should be adequately understood The natural h i s t o r y of a disease i s learned by studying those with the condition who have not had treatment. The course of adoles-cent i d i o p a t h i c s c o l i o s i s i s unclear i n some respects. Moe (1980, p. 90) comments that We are s t i l l f a r from the ultimate goal of knowing i t s ( s c o l -i o s i s ) etiology and determining which of the small curves are going to progress to severe curves . . . Taylor (1978a) suggests that data i s urgently needed on the natural h i s -tory of minor curvatures. Blount (1981) f e e l s the lack of accurate information about patients under observation before 1960 makes the study of the natural h i s t o r y of s c o l i o s i s over a long period d i f f i c u l t . He sees that t h i s s i t u a t i o n w i l l be improved i n the future with the a v a i l a b i l i t y of present records which document s k e l e t a l age as well as other relevant information needed to describe the natural h i s t o r y of s c o l i o s i s . 43 Studies of untreated curves during growth There are three possible outcomes f or a curve: spontaneous r e s o l u t i o n , no change and progression. As has been discussed previously more curves progress i n g i r l s than boys, and those most at r i s k for progression are immature females with curves over 10° (Rogala et a l . 1978). Ponseti and Friedman (1950) i n a review of 394 patients, 335 of whom were followed to maturity, found that the most severe progressions were r e l a t e d to early onset of the curve. Thoracic curves progressed most, with the average thoracic curve at maturity 81° ( i n 71 p a t i e n t s ) . The average curve i n the remaining cases was between 35° and 52°. Studies of untreated curves a f t e r maturity In a further study of 215 of these same patients ( C o l l i s and Ponseti 1969) most were found to have led normally productive l i v e s . While back pain was reported frequently i t was minimal and non-limiting. V i t a l c a p acities were diminished i n 45 percent but only 2 percent had more than s l i g h t dyspnea on exertion. The death rate was s i m i l a r to the general population. Nilsonne and Lundgren (1968) studied the long-term prognosis of 113 patients with i d i o p a t h i c s c o l i o s i s up to 50 years a f t e r o r i g i n a l diagnosis at the average age of 15.9 years. Only 11 of the 113 were l o s t to contact, of the remainder 56 were a l i v e and 46 had died. Mean age of death was 46.6 years. The mortality rate was calculated to be twice as high as for the general population and cardiac or pulmonary disease accounted for 60 percent of deaths. Forty-seven percent of the 44 l i v i n g patients were disabled, 76 percent of the females were unmarried, 90 percent reported back symptoms. Nachemson (1968) did a follow-up study of 117 patients 48 to 53 years a f t e r i n i t i a l diagnosis at a mean age of 14. M o r t a l i t y rate was twice that expected. In 16 of 20 patients who had died, kypho-s c o l i o t i c cardiopathy was l i s t e d as cause of death. T h i r t y percent of the patients received a d i s a b i l i t y pension. Recurring back pain occurred i n 37 of 97 i n d i v i d u a l s . I t i s agreed that curves over 60° often progress i n adulthood. Ponseti et a l . (1976) found that i n 26 percent of patients curves increased 15° or more and i n 8 percent of patients 25° or more. Some curves show l i f e l o n g increase. Reporting of spontaneous improvement of curves shows wide var-i a t i o n . Brooks et a l . (1975) found 22 percent of curves i n h i s study population of 3492 improved while Rogala reported 3 percent (19/603) improved. Improvement i s defined as v i r t u a l disappearance of the curve on the roentgenogram (Rogala et a l . 1978) or a decrease of 5° or more from i n i t i a l to f i n a l v i s i t (Brooks et a l . 1975). In Rogala's study (Rogala et a l . 1978) i t was found that 20 percent of the curves i n immature g i r l s of a magnitude of 20° to 30° did not progress. In lesser curves there was progression i n 2.1 percent of ch i l d r e n with 6° to 10° curves and 10.3 percent of c h i l d r e n with curves greater than 10°. Pro-gression f o r the purpose of that study meant increasing 5° or more to a f i n a l curve of 20° or more. The conclusion one can reach i s that there remains a lack of information from prospective studies on the natural h i s t o r y of s c o l i o s i s and r e t r o s p e c t i v e studies have a bias to give information on those curves i n the treatable range. 8. There should be an agreed upon p o l i c y on whom to treat as patients For purpose of examining t h i s c r i t e r i o n , treatment w i l l be con-sidered as a c t i v e medical follow-up which includes observation. There i s some v a r i a t i o n i n the standards for management of c h i l d r e n i d e n t i -f i e d with s p i n a l curvature p a r t i c u l a r l y i n the range of smaller curves. Howell et a l . (1980b) reports the c r i t e r i a agreed upon i n Edmonton screening programs. They focus on curves of at l e a s t 15° to avoid unnecessary r e f e r r a l s . The school nurse rechecks suspicious curves every s i x months. There i s a c t i v e follow-up of g i r l s with curves greater than 15° to be sure they are being seen. The guidelines estab-l i s h e d by an advisory panel to t h e i r programs were as follows: Interpretation of radiographic findings i n s c o l i o s i s While the prognosis v a r i e s according to age and state of matur-i t y i t may generally be said that 1) curves of l e s s than 5° are wi t h i n normal v a r i a t i o n 2) curves of 5 c-9° are i n s i g n i f i c a n t 3) curves of 10°-19° require observation with c l i n i c a l re-examination every 3 months and re X-ray a f t e r 6 months. If no change i s seen, observation i n t e r v a l can be extended to c l i n i c a l examination yearly for 2 years, with re X-ray i f change i s suspected. 4) curves of 20° or over should be referred and may require treatment. (Howell et a l . 1980, p. 2) If treatment includes observation as some orthopedists suggest, "observation i s a c t i v e treatment" ( T i b b i t s 1980), and the S c o l i o s i s Research Society categorizes i t as^the f i r s t l e v e l of treatment, then u s u a l l y persons with curves over 10° are those considered by most experts i n the l i t e r a t u r e to require treatment. Otherwise Rogala et a l . (1978) would suggest progression of a curve by 5° or more to over 20° places 46 the person in the treatment category. The immature female with a curve 11° or more is most at risk and should be observed closely. Taylor (1978a) suggests there is no sound basis for management of curves under 25°, found by screening programs. He warns of the potential hazards of over exposure to radiation which could occur i f X-rays were taken at frequent intervals over an extended period of time to observe small curves. Earlier Brooks et al. (1975) recommended follow-up of 5° curves but in a more recent discussion (1980) suggested that 11° and greater curves should be followed. Kane (1977a) says any immature individual with a curve of 20° deserves treatment and any immature individual with a curve over 10° is "at risk" and should be followed. These two groups constitute the scoliosis population, in his opinion. Blount (1981) suggests that there has been failure to recognize the skeletal age in considering whether to brace patients with moderate scoliosis. The magnitude of the curve is too often the sole criterion. A progressive curve should be treated at an early age. Bracing will not be effective for an unacceptable curve in an almost mature indivi-dual. Although the curve may improve i t will return to its prebrace level later because there has been no vertebral reshaping with growth. In Sweden where school children are regularly examined for scoliosis few patients in whom brace treatment is begun early require surgery later (11 of 477 patients where curve was less than 40°) (Torell et al. 1981). There is some lack of agreement on who to treat as a scoliosis patient. All would agree that immature individuals are the ones "at 47 r i s k " but whether the l e v e l for concern i s at 11°, 15° or 25° v a r i e s with the pu b l i c a t i o n . 9. There should be economic balance of the cost of case-finding i n  r e l a t i o n to t o t a l expenditure on medical care There are l i m i t s to the resources which any society can devote to health care. Funds spent i n one area mean benefits foregone i n another. Wilson and Jungner (1968) suggest i t would be h e l p f u l to compare the economics of medical care through screening with the r e s u l t s of the same expenditure on conventional care. To do th i s they suggest a prospective study i s needed to determine i f morbidity has been reduced and working l i f e improved i n a screened population compared to an unscreened sample. Cochrane and Holland (1971) have suggested that the dec i s i o n of whether the cost of screening i s reasonable can be made by costing screening programs c a r e f u l l y and then asking a group of lay and medical people whether such cost i s acceptable. There i s a dearth of information about the cost of s c o l i o s i s screening i n r e l a t i o n to t o t a l costs and no experimental evidence a v a i l a b l e . Moe et a l . (1978) c i t e s a study of Drummond i n Montreal i n which "cost accounting" was done. Cost of screening was calculated at $1684 per 400 students. The assumption was made that of 400 ch i l d r e n one would require s u r g i c a l treatment ( i f screening had not occurred) so that without screening the cost would be $5500. Deta i l s are not av a i l a b l e , but one would question what was included i n the calculated costs of screening and whether a l l r e f e r r a l and follow-up services including X-ray, physiotherapy, orthoptics and physician v i s i t s f o r both true and f a l s e p o s i t i v e are calculated. Further discussion of costs i s found under c r i t e r i o n 11. 10. Case-finding should be a continuous process and not a "one-time"  project Wilson and Jungner (1968) suggest the single-occasion examina-t i o n i s usually of l i m i t e d value, p a r t i c u l a r l y i n terms of "weeks" or " f a i r s " because only a small proportion of the population i s reached and only those who have the condition at that p a r t i c u l a r time. They suggest that continuing examinations of the population at r i s k have great advantages. In the case of adolescent i d i o p a t h i c s c o l i o s i s the disease i s l i k e l y to show early signs between the ages of 10 and 15 years and so the reported options for screening have been one or more examinations during that early adolescent period and i n some cases a one-time screen-ing test has been considered adequate. The S c o l i o s i s Research Society suggests that although a l l screening i s u s e f u l a "onee-and-done e f f o r t " i s not adequate and they recommend annual screening i n the f i f t h through tenth grades. Rogala et a l . (1978) i n a prospective study i n Montreal described screening of both grade s i x students and those i n grades seven and eight. I t was concluded that screening between ages 12 to 14 years was most successful. In Scarborough d i s t r i c t , Ontario (Williams and Tice 1980) screening was done i n grade s i x and grade eight. In Edmonton grade ••: seven g i r l s were screened i n the evaluative program taking place there. Lonstein et a l . (1976) suggests yearly screening during the "at r i s k " years which he defines as ages 10 to 13 or grades f i v e through eight. 49 In Sweden screening i s performed by school doctors and nurses as part of routine medical screening usually at ages 7, 11 and 14 ( T o r e l l et a l . 1981). Wingate (1977) i n her plan for an urban program had the objective of screening c h i l d r e n annually between ages 8 and 16. Frost's (1978) plan for a statewide program i n Hawaii describes the i d e a l target group for screening as including c h i l d r e n age 10 to 15 but due to r e a l i t i e s of l i m i t e d personnel and time, one age group -grade seven - was considered an adequate target group. Most s c o l i o s i s screening programs described i n the l i t e r a t u r e have been on-going programs however they usually aim at screening once only - i n early adolescence. 11. Cost-benefit and cost-effectiveness c h a r a c t e r i s t i c s of mass  screening and long-term therapy must be known. A mechanism for  weighing costs against benefits should be a component of I n i t i a l  screening a c t i v i t i e s . The long-term benefits must outweigh the  costs i n c l u d i n g therapeutic costs and detriments due to l a b e l l i n g , The c r i t e r i a r e l a t i n g to estimation of benefits are considered together. The lack of studies measuring costs and benefits of screening for s c o l i o s i s i s noted by V e r r i e r et a l . (1979), although she comments that there i s a general b e l i e f that benefits outweigh the costs. I t i s her contention that the benefits which accrue from s c o l i o s i s screening are those due to secondary prevention, that i s , the prevention of early death, d i s a b i l i t y and extensive care. Cost includes a l l costs of screening, follow-up, diagnosis, observation and treatment of those r e f e r r e d for care. The problem of i d e n t i f y i n g and measuring the intangibles such as s o c i a l and emotional costs and benefits both for the c o r r e c t l y and i n c o r r e c t l y l a b e l l e d i s also recognized. The issue of i n d i v i d u a l versus public benefit i s discussed by Williams and Tice (1980). Some might argue one c h i l d saved from s p i n a l fusion j u s t i f i e s a program, while from a s o c i e t a l viewpoint the d i r e c t costs from screening and medical care and the i n d i r e c t costs f o r worry and time, may be excessive i n terms of the actual benefits gained. The d i f f i c u l t y for the administrator i n public health occurs because while the health unit may be aware of i n d i v i d u a l s who are helped, the o v e r a l l costs are not appreciated because of lack of a v a i l a b l e information about program r e s u l t s (Williams and Tice 1980). No mechanism for assessing costs and benefits had been designed as a feature of the screening program reviewed by Wingate (1977) , nor were estimates of costs, benefits or effectiveness of screening pro-grams a v a i l a b l e at the time of her paper. She suggests that i n the organization of a model screening program for an urban population that the costs be measured. I t i s her proposal that they include salary or a portion thereof, of the health care coordinator, cost of the time of p h y s i c a l education teachers, school nurses, therapists and physicians; costs of t r a i n i n g of personnel and costs of r e f e r r a l to physicians, p e d i a t r i c i a n s , orthopedists, physiotherapists and o r t h o t i s t s . The greatest costs w i l l be for h o s p i t a l i z a t i o n and surgery for severe cases. Other costs she includes are for l e t t e r s , postage and data c o l l e c t i o n . On the other hand, according to Wingate, benefit w i l l be exceed-i n g l y hard to measure i n d o l l a r s . Quality of l i f e considerations are mentioned as w e l l as the avoidance of physical incapacity with r e l a t e d consequences to employment. Wingate's contention i s that estimated 51 costs of surgery should be deducted from program costs on the assumption that most patients would not have needed t h i s extreme form of treatment with early detection. The r a t i o n a l e i s that early detection with brac-ing as necessary prevents curves requiring surgery. Her conclusion i s that regardless of whether benefit exceed costs, society must determine the worth of improving the q u a l i t y of l i f e f o r a small number of c i t i -zens and decide on a humanitarian basis. The aspect of f i n i t e resources and choice of the best a l t e r n a t i v e s f or those l i m i t e d d o l l a r s i s not discussed. No mention i s made of the '"opportunity cost" when resources are deployed i n screening. The opinion that society cannot a f f o r d perfect treatment for a l l patients and a l l conditions i s presented i n a discussion of the economics of the treatment of s c o l i o s i s (Dahlberg, Nachemson 1977). I t i s impor-tant to note t h i s study i s based on 1971 p r i c e s and Swedish medical p r a c t i c e , but i t i s i n t e r e s t i n g i n terms of being the only a v a i l a b l e paper on the top i c . These authors concluded that the present day t r e a t -ment of young patients with thoracic curves showed an extremely high benefit/cost and effectiveness r a t i o . They also concluded that a d e f i -n i t e economic benefit can be derived from early brace treatment i n younger patients compared to surgery at a l a t e r date. This led them to conclude that early recognition i s highly advisable. Their study i s based on data from the Swedish d i s a b i l i t y pension fund correlated with the degree of curvature f o r i n d i v i d u a l s receiving a pension. One of t h e i r premises i s that a f t e r treatment with a brace curves do not pro-gress - an inaccurate assumption i n l i g h t of the studies of Edmonson and Morris (1977) and Mellencamp et a l . (1977) who documented progress of curves a f t e r treatment ceased. 52 Aa mentioned i n discussion of c r i t e r i o n nine concerning costs, Drummond and Rogala (Dwyer et a l . 1978) estimate a saving of $600,000 i n s u r g i c a l costs a f t e r deduction of screening costs i n t h e i r study. Taylor et a l . (1978b) c r i t i c i z e s t h i s conclusion. They quote Shapiro's conclusion that cost/benefit analysis i s only useful i n very s p e c i a l circumstances. Because of the long-term follow-up required i n s p i n a l deformity, t h e i r conclusion i s that there i s not a sound basis for a c r i t i c a l study such as that of Rogala et a l . (1978). McKeown and Knox (1968) have suggested that without a balance sheet r e l a t i n g cost to b e n e f i t , i t may not be possible to decide about a screening program i n terms of a l t e r n a t i v e methods of diagnosis and treatment. On the basis of a review of the published evidence the Task Force f o r the Conference of Deputy Ministers of Health on Periodic Health Examination reported (1980) that s c o l i o s i s screening i s of doubt-f u l value i n terms of cost b e n e f i t . The lack of information about the outcome of c h i l d r e n who were treated a f t e r detection during screening i s considered a serious d e f i c i t . Because of lack of evidence as to the benefits of a p a r t i c u l a r form of therapy the committee recommended that screening be done only within the context of an evaluative study. The extremely low y i e l d from screening programs was another f a c t o r i n t h e i r recommendation. Because the Task Force Report represents a review of published reports on s c o l i o s i s and i s of recent date t h e i r conclusion must be s e r i o u s l y weighed. 12. I d e a l l y an estimate of the social, benefit of preventing, a r r e s t i n g or  curing the condition.should be known and i f community benefits- are claimed  to r e s u l t from screening t h i s benefit must withstand s c i e n t i f i c scrutiny Generally the s o c i a l b enefit claimed i s that documented i n studies 53 such as, those of Nachemson (1968), Nilsonne and Lundgren (1968), and Drummond et a l . (1976). These studies ind i c a t e the r e s t r i c t e d working a b i l i t y of patients with untreated s c o l i o s i s . In Nachemson*s study 97 patients were questioned. This group consisted of the patients a v a i l -able from a group of 130 seen between 1927 and 1936 at a major r e f e r r a l centre i n Sweden. No X-rays were a v a i l a b l e . Of the 97 patients ques-tioned: 30 percent were claiming a d i s a b i l i t y pension and the average age at which i t was claimed was 36. Another study (Nilsonne and Lundgren 1968) found almost one-half of the patients contacted were unable to work. The high proportion of unmarried (76 percent) i n Nilsonne and Lundgren's study i s another s t a t i s t i c which could be used to i l l u s t r a t e s o c i a l benefit of ea r l y treatment and prevention of cosmetic deformity. Drummond et a l . (1976) i n a Quebec study found 24 percent unemployed while 42 percent of females and 30 percent of males were unmarried. It i s important to know that the sample i n these studies i s of adolescent i d i o p a t h i c s c o l i o t i c s . Nilsonne and Lundgren (1968) mention that s c o l i o s i s due to p a r a l y s i s and r i c k e t s were, excluded from t h e i r sample but that some congenital s c o l i o s i s may be inadvertently included. As the incidence i s 5 percent f o r congenital s c o l i o s i s i n t h e i r e s t i -mation t h i s should not be s i g n i f i c a n t to the r e s u l t s . Nachemson includes untreated s c o l i o t i c s of a l l types i n h i s study and of the 130 patients, 59 were id i o p a t h i c s c o l i o s i s . I t was possible to trace 52 of these 59 patients and 10 of the 52 were 75 percent disabled. These s t a t i s t i c s f o r d i s a b i l i t y were the lowest f o r any of the f i v e types of s c o l i o s i s i n the sample. This study i s widely quoted to i l l u s t r a t e the benefit of prevention i n s c o l i o s i s and so i t i s important to know whether s o c i a l e f f e c t s described are due to s c o l i o s i s i n general or to a s p e c i f i c type. In the time of these studies there were s c o l i o t i c s who were p o l i o c asualties or r a c h i t i c . It would appear from Nachemson's paper that the sequelae of id i o p a t h i c s c o l i o s i s are the l e a s t severe. The information on Drummond's study does not i n d i -cate whether the sample i s ex c l u s i v e l y i d i o p a t h i c s c o l i o t i c patients. In summary i f benefits are to be claimed on the basis of seque-lae prevented by screening then s c i e n t i f i c scrutiny would require experimental or quasi-experimental evidence. Evidence of t h i s nature could not be found i n t h i s l i t e r a t u r e survey and i t i s questionable i f the d e s c r i p t i v e studies found are useful i n terms of claimed benefits for screening f o r i d i o p a t h i c s c o l i o s i s . This completes the ap p l i c a t i o n of 12 selected c r i t e r i a to the l i t e r a t u r e on s c o l i o s i s and s c o l i o s i s screening. Further discussion of whether the evidence j u s t i f i e s s c o l i o s i s screening i n terms of these c r i t e r i a w i l l follow i n Chapter f i v e . CHAPTER I I I METHODOLOGY Purpose of the Study This study evaluates the s c o l i o s i s screening program c a r r i e d out i n SFHD to substantiate that the program should be continued. The evaluation was done by applying established c r i t e r i a to the outcomes of screening to determine the a c c e p t a b i l i t y of both the screening test and the treatment recommended, the v a l i d i t y of the screening test and the a v a i l a b i l i t y of resources. The data from the study was analysed mainly i n r e l a t i o n to these four p r i n c i p a l c r i t e r i a but consideration was also given to the implications of the other important c r i t e r i a of screening for continuation of the program. Description of the Screening Program Time Period The time period for t h i s study was from September 1976 to June 1980 and includes the screening for s c o l i o s i s c a r r i e d on during four school years. A p i l o t project of s c o l i o s i s screening was conducted during January to June 1976 and involved 775 students from selected schools. The data from t h i s p i l o t program and the data from c h i l d r e n screened a f t e r June 1980 were not included i n t h i s study. Sample To q u a l i f y f or screening i t was required to be a student at a 56 school within SFHD (private or p u b l i c ) . SFHD i s comprised of two school d i s t r i c t s : School D i s t r i c t #43 (Coquitlam, Port Coquitlam, Port Moody) and School D i s t r i c t #40 (New Westminster). In the school years 1976-77, 1977-78, and 1978-79 only School D i s t r i c t #43 pupils were screened. In the school year 1979-80 pupils from New Westminster were included i n the screening program. In school year 1976-77 a l l grade seven pupils (N = 1879) were screened and a sampling of 35 percent of the grade eights (N = 708). In the school year 1977-78 a l l grade sevens (N = 1748) and a group of 125 rechecks from the previous year were seen (grade eight and nine students). In the 1978-79 and 1979-80 screening years only grade seven students were screened, 1690 and 1860 r e s p e c t i v e l y . The grand t o t a l of pupils screened was 8010. Both boys and g i r l s were included i n the program. No consent was required for screening. The school p r i n c i p a l sent home an explanatory l e t t e r about the program and n o t i f i c a t i o n of the date of screening. Consent was implied i f no d i s -senting communication was received by the time of screening. A l l c h i l -dren known to have s c o l i o s i s (the public health nurse would i d e n t i f y these children) were excluded from screening. Those ch i l d r e n who refused screening or for whom a note or telephone message was received advising r e f u s a l of screening were so noted on the class l i s t used by the screen-ing team. Those already known as s c o l i o t i c were included i n the figures used to determine prevalence i n t h i s study. Screening t e s t Each c h i l d was examined by one of the screening team, which consisted to two public health nurses and a physiotherapist. There 57 were four to s i x public health nurses and three physiotherapists r o t a t i n g on the teams. The physiotherapists had received t r a i n i n g from an orthopedic surgeon at the time of the p i l o t project. The nurses, some of whom were new to screening each year were trained by the physiotherapists and by use of a t r a i n i n g f i l m produced by the S c o l i o s i s Research Society. The examination consisted of viewing the c h i l d with shoes and top c l o t h i n g removed. G i r l s could wear h a l t e r s or brassieres. Pants were lowered to the l e v e l of the i l i a c c r e s t s . The c h i l d was f i r s t examined standing erect, f a c i n g away from the examiner with weight equal on both feet and arms at sides. The examiner noted: shoulder l e v e l , l e v e l of i n f e r i o r angles of scapula, waist angles, i l i a c crest l e v e l , dorsal superior i l i a c spine l e v e l , and plumb bob alignment from seventh c e r v i c a l vertebrae. Next the c h i l d was examined standing, f o r -ward flexed, with hands clasped i n f r o n t , head w e l l flexed and knees s t r a i g h t . The examiner then noted the l e v e l of thoracic and lumbar region. The screener was looking for a raised area at the side of the spine which i s the c l a s s i c r i b hump of thoracic s c o l i o s i s . C r i t e r i a for r e f e r r a l Any one of the following was considered a p o s i t i v e sign of s c o l -i o s i s : presence of a thoracic and/or lumbar elevation, s h i f t of spine, waist angle change, p e l v i c asymmetry, one prominent shoulder blade or cafe au l a i t spots (neurofibromatosis). These standards were used con-s i s t e n t l y i n a l l years of screening under consideration i n t h i s study. A screening p o s i t i v e was a student with one of the signs of s c o l i o s i s which had been confirmed during rescreening two days l a t e r 58 by another physiotherapist. Upon the decision to l a b e l the c h i l d as p o s i t i v e , a l e t t e r was mailed to the parent. The d i s t r i c t p ublic health nurse telephoned the parents to explain the recommendations and give reassurance. This c a l l was made on the day of the rescreening, i n the evening i f necessary. R e f e r r a l procedure Accompanying the l e t t e r to the parent was a l e t t e r from the physician to be presented to him by the parent at time of the medical examination. The family doctor was requested to: a) re-examine the c h i l d , e s p e c i a l l y i n forward f l e x i o n b) have a standing X-ray done i f there was agreement .with the findings c) r e f e r to an orthopedic surgeon i s signs were confirmed on X-ray. The physician was requested to write h i s findings on the back of the l e t t e r of r e f e r r a l and mail h i s reply i n the stamped addressed envelope provided by the health d i s t r i c t . When the p i l o t program was i n i t i a t e d an orthopedic surgeon was a c t i v e l y involved i n the planning stages. A meeting was held of ortho-pedic surgeons working i n the health d i s t r i c t at which time i t was agreed that one of them, an orthopedic surgeon, would take primary r e s p o n s i b i l i t y for r e f e r r a l s from the program. This d e c i s i o n was d i s -cussed at a meeting of the New Westminster Medical Society so that general p r a c t i t i o n e r s who made r e f e r r a l s to orthopedists would be aware of t h i s agreement. This informal p o l i c y was i n e f f e c t during the period of screening under review. 59 Confirmed p o s i t i v e s The presence of a curve greater than 10° (Cobb method) on a thoracic-lumbar a n t e r i o r - p o s t e r i o r X-ray was considered orthopedically p o s i t i v e f or the purpose of t h i s study. As w e l l any orthopedist's confirmation of " s c o l i o s i s — t o be followed" was considered p o s i t i v e u n t i l X-ray confirmation of the degree of curvature. Program data Class l i s t s were used during screening so that every c h i l d examined was recorded. Any screening r e f u s a l s were noted on these l i s t s as were absentees. There was an attempt to screen absentees on the day of rescreening. From the physician reports and public health nurse contact of parents and physicians, a record card was completed by the physiotherapists for each c h i l d who i n i t i a l l y f a i l e d screening. For the period of t h i s study 169 screening p o s i t i v e s have been i d e n t i -f i e d . The records for these 169 c h i l d r e n were examined for complete-ness of outcome information. For 47 c h i l d r e n there was complete i n f o r -mation noted and no further contact was necessary. Study Method The record cards for the remainder (122) were s c r u t i n i z e d and checked for an up-to-date address and phone number. Health D i s t r i c t records, telephone book, student d i r e c t o r i e s and school records were used to confirm the l o c a t i o n . There were f i v e cases where a current address was not a v a i l a b l e , however, i n each case enough outcome i n f o r -mation was a v a i l a b l e from i n i t i a l health d i s t r i c t contact to include them i n the sample. The new addresses of three cases away from the 60 d i s t r i c t were a v a i l a b l e and these parents were contacted by l e t t e r and asked to reply to the same questions posed i n the telephone interview. A l l r e p l i e d including a family traced to C a l i f o r n i a . For those 114 cases i n which information was incomplete and an address was av a i l a b l e the following procedure was followed: 1) F i r s t a l e t t e r of introduction from SFHD was sent to the parents of the 114 c h i l d r e n (Appendix A) before any contact was made. 2) One week following the mailing of these l e t t e r s telephone interviews began, during which parents were asked about the outcomes of the r e f e r r a l of t h e i r c h i l d following screening (Appendix B outlines the interview format). A l l parents cooperated by giving information. From these interviews records for 68 c h i l d r e n were completed. 3) For the remaining 46 c h i l d r e n a contact to the physician was necessary to complete the outcome information. The parents were asked at the time of the telephone interview i f they consented to physician contact. A consent (Appendix C) was mailed with an enclosed stamped addressed envelope to the 46 f a m i l i e s . 4) P r i o r to the investigator contacting the physician a l e t t e r of introduction was mailed from SFHD (Appendix D). The purpose of th i s l e t t e r was to explain the objective of the s c o l i o s i s program evaluation and encourage physician cooperation i n completing the questionnaire. 5) As the parental consents were received they were mailed along with the questionnaire to each physician (Appendix E), including a stamped addressed envelope f o r the reply. The orthopedic s p e c i a l i s t who received the majority of r e f e r r a l s from the family doctors was con-tacted d i r e c t l y and an arrangement made to work d i r e c t l y i n hi s medical records system. 61 At t h i s point i n the study a mail s t r i k e was threatened and so a p o s t s c r i p t was added to the questionnaire that pickup of the com-pleted questionnaire would be arranged upon a telephone c a l l to the i n v e s t i g a t o r . C a l c u l a t i o n of Resources Used Resources required for a screening program include the resources to carry out the screening procedure i t s e l f and those that provide diag-nosis and treatment as necessary to those who are referred from the program. To describe resources u t i l i z e d , the amount of s t a f f time used i n the screening program was tabulated for physiotherapists, public health nurses and c l e r k s , according to each program year. Diagnostic and treatment resources were categorized as medical, X-ray, o r t h o t i c and physiotherapy. From the information given i n the interviews and questionnaires any problems encountered i n obtaining services i n any of the necessary areas; medical, X-ray, o r t h o t i c or physiotherapy, were documented. The r e s u l t i n g tabulations are presented i n Chapter four. Because there are implications for province-wide a p p l i c a t i o n of screening the l o c a t i o n of orthopedic surgeons and o r t h o t i s t s i n B.C. was determined. To obtain t h i s information the Medical Directory pub-l i s h e d by the College of Physicians and Surgeons of B r i t i s h Columbia and the l i s t of C e r t i f i e d O r t h o t i s t s of the B.C. Association of Ortho-t i s t s was consulted. These data are also found i n Chapter four. Economic evaluation I t i s accepted that evaluation of evidence that a screening measure i s e f f e c t i v e should precede economic evaluation of the program 62 (McKeown and Knox 1968; Sackett 1975a). The question of effectiveness of the screening measure (that i s , i t s v a l i d i t y ) i s to be assessed i n t h i s study, as w e l l as i t s a c c e p t a b i l i t y and the a c c e p t a b i l i t y of the treatment for the condition. There i s no point i n economic evaluation of a measure which i s not v a l i d nor acceptable, or which r e s u l t s i n detection of a condition for which no acceptable treatment e x i s t s . For t h i s reason a complete economic evaluation i s not attempted. Instead the time used by health d i s t r i c t s t a f f has been estimated and data i s presented under the discussion of a v a i l a b i l i t y of program resources (see Chapter fou r ) . Such tabulation may prove u s e f u l to the health d i s t r i c t i n planning the deployment of s t a f f . I f program a l t e r n a t i v e s are considered information about the amount of time a v a i l a b l e from c a n c e l l a t i o n of s c o l i o s i s screening could be h e l p f u l . The cost of the screening program derived by multip l y i n g the un i t costs by the number of services has been estimated to provide some measures of the d i r e c t cost of the screening procedure and for the cost of diagnostic and treatment services r e s u l t i n g from screening, for both screening p o s i -tives and negatives. Methods of Analysing Program Data To determine the outcomes of s c o l i o s i s screening for the period under review t h i s i n v e s t i g a t o r examined a l l a v a i l a b l e r e s u l t s of screen-ing. The data was reviewed as follows. Class l i s t s Each l i s t was examined to determine the number of c h i l d r e n screened and the number noted as screening r e f u s a l s . Record cards The investigator reviewed each of the screening p o s i t i v e s and tabulated the t o t a l number and the number of: 1) r e f u s a l s for r e f e r r a l at any l e v e l 2) r e f e r r a l s to family doctor 3) r e f e r r a l s to orthopedic surgeon 4) chi l d r e n X-rayed by family doctor and by orthopedist 5) c h i l d r e n who were screening p o s i t i v e and orthopedically negative (le s s than 11° curve) 6) c h i l d r e n who were orthopedically p o s i t i v e (greater than 10°) 7) c h i l d r e n who were already known to have s c o l i o s i s 8) c h i l d r e n with other s p i n a l disease 9) unknown outcomes The orthopedic p o s i t i v e s were analysed and are described by: 1) the i n i t i a l curve and number remaining stable, progressing and decreasing 2) the follow-up received - observation, physiotherapy, bracing, surgery, and other such as c h i r o p r a c t i c e s e r v i c e s , and non-acceptance at any l e v e l 3) d i s t r i b u t i o n by sex Quantitative analysis Data c o l l e c t e d from a l l sources including class l i s t s , record cards, interviews, questionnaires, previous health d i s t r i c t reports on s c o l i o s i s , S t a t i s t i c s Canada, Mini s t r y of Health, Research D i v i s i o n , Medical D i r e c t o r i e s and other are categorized and presented i n tables and narrative form i n Chapter four. 64 The f o u r f o l d table Using the generally accepted f o u r f o l d table i l l u s t r a t e d i n Figure 2, Grant (1974) has constructed a model from which u s e f u l e v a l -uative indices can be calculated. Screening Results Diseased DIAGNOSIS Nondiseased T o t a l P o s i t i v e Negative T o t a l a c a + c b d b + d a+ b c+ d a + b + c + d F i g . 2 . — F o u r f o l d table c l a s s i f y i n g p a r t i c i p a n t s i n a screening program. The subjects i n the preceding table are c l a s s i f i e d as follows: a = true p o s i t i v e s , diseased persons detected by screen b = f a l s e p o s i t i v e s , nondiseased persons screened p o s i t i v e c = f a l s e negatives, diseased persons not detected by screen d = true negatives, nondiseased persons screened negative Status of screening negatives Grant suggests that to overcome the d e f i c i t i n information about the status of the screening negatives (that i s , whether they are diseased or nondiseased) a technique be borrowed from the methodology of systems analysis. A "research estimate" i s the key to the*quantitites "c" and "d". Of the four methods for estimating disease prevalence l i s t e d by Grant, a prevalence estimate from another study on a population demo-graphically comparable was the one chosen for t h i s analysis. The prospective study of Rogala et a l . (1978) was selected for t h i s purpose. The proposed model i s summarized i n Figure 3. The key, the t o t a l number diseased i n the population (a + c) i s obtained by multip l y i n g the t o t a l screened by the prevalence estimate obtained from other studies. Step 2 C l a s s i f i c a t i o n of screen p o s i t i v e s by c l i n i c a l diagnosis c Step 3 Estimation of disease prevalence a + c b + d a-fcb+c+d ) C l a s s i f i c a t i o n of the population by screening F i g . 3 . — A n a l y t i c a l d e r i v a t i o n of the f o u r f o l d table. SOURCE: John A. Grant, "Quantitative Evaluation of a Screening Program," AJPH, Jan. 1974, 64:1, p. 69. Ap p l i c a t i o n of the model Using the prevalence estimate of the disease to c a l c u l a t e t o t a l diseased as proposed by Grant allows completion of a f o u r f o l d table and c a l c u l a t i o n of the measures of v a l i d i t y . 1) The model was used to evaluate s e n s i t i v i t y — f — , i . e . the J a + c proportion of the t r u l y diseased who were c o r r e c t l y i d e n t i f i e d . 2) The model was used to evaluate s p e c i f i c i t y '^ > i . e . the proportion of the t r u l y non-diseased who were c o r r e c t l y i d e n t i f i e d . 66 3) The model was used to determine o v e r r e f e r r a l —7—r- , or a + b f a l s e p o s i t i v e s , i . e . the r a t i o of non-diseased persons with p o s i t i v e screens to a l l those refer r e d . 4) The model was used to determine underreferral ;—- , or c + d f a l s e negatives, i . e . the r a t i o of diseased persons with negative screen to a l l those not ref e r r e d . 5) The model was used to determine the p o s i t i v e p r e d i c t i v e value j- , the p r o b a b i l i t y that a patient with a p o s i t i v e screening test i s a a diseased. 6) The model was used to determine the t o t a l p r e d i c t i v e value a + d —7-7 -—; ;—7 , the p r o b a b i l i t y that the test c o r r e c t l y i d e n t i f i e s the a + b + c + d r e c i p i e n t (both p o s i t i v e s and negatives). E t h i c a l Review A request for e t h i c a l review of a c t i v i t i e s i n v o l v i n g human sub-j e c t s i n questionnaires, interviews, observations, t e s t i n g , video and audio tapes, etc. was submitted to the University of B r i t i s h Columbia Screening Committee f o r Research and Other Studies Involving Human Subjects: Behavioural Sciences. Permission to proceed with the study was received (Appendix F). The telephone interviews and questionnaires were administered by the investigator while on educational leave from her p o s i t i o n as nursing supervisor of the Simon Fraser Health D i s t r i c t . She i s an experienced public health nurse who i s f a m i l i a r with the interviewing process and the need f o r respect of c o n f i d e n t i a l i t y i n the gathering of data from i n d i v i d u a l s . She has the endorsement of the Deputy Minister of Health for t h i s study (Appendix G). CHAPTER IV RESULTS OF THE SCREENING PROGRAM The r e s u l t s of s c o l i o s i s screening w i l l be presented r e l a t i v e to the four p r i n c i p a l c r i t e r i a which have been selected f or t h i s study as most useful i n evaluation of the program at Simon Fraser Health D i s t r i c t . A c c e p t a b i l i t y of the Screening Test To assess the a c c e p t a b i l i t y of the screening t e s t to the popula-t i o n consideration w i l l be given to a c c e p t a b i l i t y of the test to 1) par-ents, 2) c h i l d screened and 3) physicians. 1) A c c e p t a b i l i t y to parents A measure of the a c c e p t a b i l i t y of screening to parents i s the proportion of r e f u s a l s to consent to screening of t h e i r c h i l d . As mentioned previously the school cl a s s l i s t s were searched and the number of c h i l d r e n who were exempted from screening noted along with the reason i f one was given. Of 8031 ch i l d r e n a t o t a l of 21 refus-a l s (0.3 percent) were received i n the four years of the screening program under review. In nine cases the reason given was a s p i n a l problem under medical care. Two exemptions were also asked on the basis that the family chiropractor would check the child's: spine. In ten cases no reason was given. The r e s u l t s are tabulated i n Table I I . 68 TABLE II REFUSAL OF CONSENT FOR SCREENING reason for r e f u s a l number screened t o t a l of refusa l s known problem chiropractor would screen no reason given 1967-77 2587 2 - - 2 1977-78 1873 9 4 2 3 1978-79 1690 5 2 - 3 1979-80 1860 5 3 - 2 Total 8010 21 9 2 10 During the 114 telephone interviews c a r r i e d out by t h i s i n v e s t i -gator to complete data on screening outcomes, with few exceptions there was widespread endorsement by parents of the screening program. One parent c r i t i c i z e d the n o t i f i c a t i o n process, as she had been, shocked by the a r r i v a l of the l e t t e r advising r e f e r r a l . She had not received a phone c a l l of explanation before the l e t t e r ' s a r r i v a l as i s the recom-mended health d i s t r i c t p r a c t i c e . When the program was evaluated for a c c e p t a b i l i t y i n 1977 and 1978 some parents f e l t more explanation about the disease of s c o l i o s i s would be h e l p f u l . Subsequently the health d i s t r i c t provided school p r i n c i p a l s with a model l e t t e r explaining the program and a b r i e f des-c r i p t i o n of s c o l i o s i s which could be d i s t r i b u t e d at the time of n o t i f i -c a tion of the screening date. 69 2) A c c e p t a b i l i t y to the c h i l d screened Only one documentation of r e f u s a l to be screened by the p u p i l (N = 8022) i s noted on survey of the class l i s t s . The screening team has reported that self-conscious g i g g l i n g and remarks were common during the screening procedure. Attitudes appeared to be improved with the introduction of a short explanatory t a l k by the school nurse a few days p r i o r to the screening session. The ch i l d r e n were to l d what to expect of screening and what wearing apparel was s u i t a b l e . Absentee rate has been assessed and was normal at the time of screening. This can be considered as an unobtrusive measure of the a c c e p t a b i l i t y of the screen-ing procedure. When parents (N = 114) were interviewed during t h i s study three commented on the anxiety experienced by t h e i r c h i l d r e n due to the rescreening examination at school. In one case the c h i l d had a f r i e n d who had j u s t had surgery f o r s c o l i o s i s and he was very apprehensive. During previous evaluation of the screening program when a public health nurse v i s i t e d a random sample of fa m i l i e s (N = 31) to ask t h e i r reaction to the program nine (29 percent) mentioned that t h e i r daughters were very self-conscious about being examined by health unit personnel (Ladner 1978). 3) A c c e p t a b i l i t y to the physicians When a sample of ten physicians was interviewed by the Assistant Medical Health O f f i c e r i n 1977 a l l indicated approval of the program. These ten were selected randomly from those physicians (N = 82) who had received a r e f e r r a l from the program during school year 1976-77. In two instances (2 percent) during the study interviews (N = 114) to com-ple t e data f o r t h i s study parents reported the comment of t h e i r physi-cian that the r e f e r r a l had been a "waste of time". A c c e p t a b i l i t y of Treatment Treatment a l t e r n a t i v e s There were f i v e approaches to treatment documented a f t e r a c h i l d was diagnosed i n th i s program as s c o l i o t i c : 1) observation at regular i n t e r v a l s , 2) placement on an exercise program under physiotherapist supervision, 3) bracing, 4) surgery, or 5) other care such as c h i r o -p r a c t i c . The same c h i l d could progress from one category to another as a r e s u l t of change i n the curve and treatment might be refused at any stage. The following table (Table III) i l l u s t r a t e s the treatments u t i l i z e d by those children who were diagnosed s c o l i o t i c . TABLE III TREATMENT OF ORTHOPEDIC POSITIVE CHILDREN year t o t a l observed • only physio brace surgery other* 1976-77 17 9 8 1 3 1 1977-78 14 10 2 2 - -1978-79 5 2 - 2 3 1 1979-80 4 3 - 1 - -T o t a l 40 24 10 6 6 2 *Chiropractic care i n these cases ( s e l f - r e f e r r a l ) . 71 1) Observation includes those c h i l d r e n under the supervision of ei t h e r the family physician or the orthopedic s p e c i a l i s t . Children i n t h i s category are presumed "at r i s k " f o r a progressive curve because they had a curve greater than 10° and were s k e l e t a l l y immature. They were seen at i n t e r v a l s of from three months to one year, with X-ray examination on some or a l l v i s i t s . The number f a i l i n g to comply with the recommendation for observation are noted i n Table IV. 2) Phys i o therapy i n the ten cases treated by t h i s means alone, usually involved a continuous program of exercises under the supervision of a physiotherapist i n a c l i n i c a l s e t t i n g ( h o s p i t a l or o f f i c e ) concur-rent with a home program. Royal Columbian Hospital offered a tri-weekly program of group physiotherapy for s c o l i o s i s patients and eight of the ten patients attended this program. Some of the c h i l d r e n have been treated for over two years. Others have had shorter periods of t r e a t -ment (two months to s i x months). The recommendation for treatment by physiotherapy was accepted i n a l l cases. 3) Brace treatment was prescribed for nine chi l d r e n . Three refused bracing and of these, two have had surgery. The t h i r d g i r l has a 38° curve and i s under c h i r o p r a c t i c care. Of the s i x ch i l d r e n who were braced one c h i l d was f i t t e d and wore her Milwaukee brace only a few hours before r e j e c t i n g i t completely. She required s u r g i c a l cor-r e c t i o n one year l a t e r and received c h i r o p r a c t i c treatment during the intervening year. Two c h i l d r e n each wore t h e i r braces for about 15 months but t h e i r curves progressed to the degree that surgery (Harrington Rod and s p i n a l fusion) was required. Of the remaining three g i r l s i n braces one began brace treatment i n September 1980 (10 months ago) and 72 has been maintained s u c c e s s f u l l y . She i s seen by the orthopedic surgeon every three months and i s X-rayed on every second v i s i t . Her curve of 27° i s reported as "holding steady" and i t i s anticipated that she w i l l be i n her brace at l e a s t u n t i l September 1982. Another c h i l d has been maintained i n a brace since January 1979 for a 28° curve. In the two and a h a l f years of brace treatment the curve has reduced to 16° and the g i r l i s now being weaned from the brace eight hours d a i l y . The t h i r d g i r l moved to C a l i f o r -n i a a year a f t e r r e f e r r a l from screening. She was under observation of her family doctor p r i o r to her move but no X-ray was taken. In C a l i f o r n i a she was referred to an orthopedic surgeon who placed her i n a modified brace f i t t e d below the shoulder blades to h i p l i n e . Her mother writes that she i s seen every four months with X-rays and that she does exercises d a i l y . S u r g i c a l c o r r e c t i o n was c a r r i e d out on s i x g i r l s who had placement of a Harrington Rod and subsequent s p i n a l fusion. As mentioned previously two of this category were brace f a i l u r e s and three rejected bracing. The remaining case was not considered s u i t a b l e for c o r r e c t i o n by the Milwaukee brace. A l l the corrections are reported to be successful. One g i r l i s wearing a brace post-operatively (for s i x months) and another w i l l have a portion of the rod removed because i t has become troublesome. Surgery was refused by three g i r l s . The t o t a l resources u t i l i z e d for these orthopedic p o s i t i v e cases and for those who were screening p o s i t i v e but orthopedically negative, w i l l be discussed i n d e t a i l under the a v a i l a b i l i t y of resources. Refusals.of r e f e r r a l recommendation For a successful screening program besides acceptance of the screen-ing test there must be acceptance of the recommendations which follow for those who are determined to be a screening p o s i t i v e . There are several stages at which there may be non-compliance. F i r s t there may be r e f u s a l to obtain a medical assessment as recommended. This occurred i n 2 of the 169 i n th i s study. Of those who do see t h e i r family physician a c e r t a i n number w i l l f a i l to follow h i s recommendations for continued observation, 2 of the 37 are i n th i s category. At a further stage, the orthopedist w i l l recommend a c e r t a i n course of action f o r those c h i l d r e n who are ref e r r e d to him, 20 of the 82 e l i g i b l e , a rate of 25 percent (65 for observation, 9 for bracing, 9 for surgery with one g i r l r e f u s i n g two treatment modes), disregarded the recommendation made. In the majority of those cases the curve had been minor and non-progressive. One mother gave "concern about unnecessary r a d i a t i o n " as the reason for not return-ing to the orthopedic s p e c i a l i s t . Table IV outlines the l e v e l s and numbers for non-compliance. TABLE IV REFUSAL OF REFERRAL RECOMMENDATION f a i l e d to f a i l e d to refused complete observation complete observation refused refused t o t a l r e f e r r a l (N = 169) (family Dr.) (N = 37) ( s p e c i a l i s t ) (N = 65) brace (N = 9) surgery (N = 9) 1976-77 84 1 7 2* 3* 1977-78 42 - 1 6 - -1978-79 17 - 1 2 -1979-80 26 1 1 1 - -T o t a l 169 2 2 15 4 3 *0ne of the bracing refusa l s had a progressive curve, surgery was then recommended and refused. Physiotherapy was not tabulated as there were no known r e f u s a l s i n the 10 cases treated by this means alone. 74 V a l i d i t y of the Test The v a l i d i t y of the screening test i s evaluated by i t s a b i l i t y to c o r r e c t l y i d e n t i f y c h i l d r e n who have the disease and those who do not. In order to assess v a l i d i t y one must know 1) the screening p o s i -tives and negatives, 2) the diagnostic p o s i t i v e s ( c a l l e d orthopedic p o s i t i v e s i n t h i s study) and negatives, and 3) the true prevalence. From t h i s information a f o u r f o l d table i s constructed which allows c a l c u l a t i o n of recognized measures of v a l i d i t y ; s e n s i t i v i t y , s p e c i f i c i t y , o v e r r e f e r r a l and underreferral rates and the p r e d i c t i v e value of the te s t , using the method of Grant (see Chapter three). The l a s t consideration of v a l i d i t y w i l l be a d e r i v a t i o n of the prevalence rate of s c o l i o s i s i n the SFHD screening population. Table V gives the r e s u l t s of the screening tests and the diag-n o s t i c tests with tabulation of the p o s i t i v e s and negatives. TABLE V RESULTS OF SCOLIOSIS SCREENING 1976-1980 IN SFHD SCREENING TEST DIAGNOSTIC TEST number orthopedic orthopedic year screened p o s i t i v e negative p o s i t i v e negative unknown other** 1976-77 2587 84 2503 17 65 1 1 1977-78 1873 42 1831 14 (+1)* 27 - -1978-79 1690 17 1673 5 (+1)* 9 - 2 1979-80 1860 26 1834 4 " 20 1 1 Total 8010 169 7841 40 (+2) 121 2 4 *Orthopedically p o s i t i v e but previously i d e n t i f i e d and under care. **0ther s p i n a l disease. 75 1) Screening p o s i t i v e s and negatives There were a t o t a l of 8010 c h i l d r e n screened during the four years of the program at SFHD. Of these, 169 met the c r i t e r i o n of "screening p o s i t i v e " and 7841 were "screening negative". The c r i t e r i a f o r a screening p o s i t i v e were described i n Chapter two. In c h i l d r e n c a l l e d "screening negative" no sign of s c o l i o s i s was present on screen-ing. The signs of s c o l i o s i s were l i s t e d i n Chapter three. 2) Orthopedic p o s i t i v e and negative The recognized diagnostic measure for s c o l i o s i s i s the standing a n t e r i o r - p o s t e r i o r thoraco-lumbar X-ray. A curve of 11° or more on X-ray was considered an "orthopedic p o s i t i v e " or confirmed s c o l i o s i s i n th i s study. In the case of some r e f e r r a l s the orthopedic surgeon deferred X-ray and observed the c h i l d p e r i o d i c a l l y . U n t i l these c h i l -dren had a diagnostic X-ray they were presumed p o s i t i v e . Any curve which reached 11° or greater was l a b e l l e d a p o s i t i v e for the purpose of t h i s study. Those who were not confirmed by a diagnostic test or followed by an orthopedist as a s i g n i f i c a n t curve were considered negative. Children who were l a b e l l e d negative were not necessarily X-rayed but a l l were examined by a physician who pronounced them as negative. In the study sample there were two cases where r e f e r r a l was not completed and four c h i l d r e n with s p i n a l disease other than i d i o p a t h i c s c o l i o s i s . This i s noted i n Table V as "other". A l l these c h i l d r e n were diagnosed previous to screening. The other s p i n a l diseases repre-sented were s c o l i o s i s secondary to: Marfan's syndrome, Scheuermann's 76 disease, neurological disease and post-operatively following c o r r e c t i o n of pectus excavatum. While none of these four cases are orthopedic p o s i t i v e s as defined they, do i l l u s t r a t e that screening for s c o l i o s i s may i d e n t i f y other s p i n a l pathology. Description of orthopedic p o s i t i v e s The orthopedic p o s i t i v e s are a very s i g n i f i c a n t group and w i l l be described i n terms of sex, degree of curvature and progression of curves. Sex d i s t r i b u t i o n of the orthopedic p o s i t i v e s i s presented i n Table VI. Of the t o t a l of 40 (N = 169) who were categorized as p o s i -t i v e , 4 were male (10 percent) and 36 were female (90 percent), for a r a t i o male to female of 1:9. TABLE VI SEX OF ORTHOPEDICALLY POSITIVE CASES year number male female 1976-77 17 2 15 1977-78 • 14 2 12 1978-79 5 - 5 1979-80 4 - 4 Tot a l 40 4 36 The degree of curvature on i n i t i a l X-ray examination ranged from 10° to 38°. The two 10° curves were included i n the orthopedic p o s i t i v e group because they subsequently progressed so that they met the 77 q u a l i f i c a t i o n s of orthopedic p o s i t i v e (see page nine). One c h i l d had not been X-rayed but i s examined every s i x months by an orthopedic surgeon who has categorized her as c l i n i c a l l y p o s i t i v e and s k e l e t a l l y immature. For these reasons she too q u a l i f i e s as orthopedic p o s i t i v e . Of the 38 curves, 25 (65.8 percent) are between 10° and 19°, 10 (26.3 percent) l i e between 20° and 29° and 3 (7.9 percent) are greater than 30°. One curve has not been X-rayed and the X-ray status of a g i r l i n brace treatment i n C a l i f o r n i a i s not known. Progression of curves i s revealed by p e r i o d i c X-ray examinations. Of those curves (36 of 38) which have been followed r a d i o g r a p h i c a l l y , 13 (36.1 percent) showed progression ranging between 1° and 20°, 16 (44.4 percent) remained unchanged and 7 (19.4 percent) decreased from 1° to 6°. None of the 25 curves which were below 20° i n i t i a l l y has required treatment. Of the 13 curves greater than 20°, 8 have received a c t i v e treatment by bracing or surgery. Of the 25 curves below 20°, 5 or 20 percent progressed whereas i n the 13 curves over 20°, 80 percent of those followed by X-ray increased (8 of 10), two were operated on immediately and one refused follow-up. Of the four curves occurring i n males none progressed. Figure 4 i l l u s t r a t e s the pattern of curva-tures i n the sample. 3) True prevalence As discussed i n chapter three the f i g u r e for true prevalence i s necessary to complete the f o u r f o l d table and determine measures of v a l i d i t y such as s e n s i t i v i t y , s p e c i f i c i t y and p r e d i c t i v e value. The number of t o t a l diseased i n the population i d e a l l y would be 7° / 0 ° 15° 2 0 ° 2 5 ° 30° JS° - V O " V 5 ° 5 0 ° INITIAL CURVE Fi g . 4 . — P a t t e r n of progress of s c o l i o s i s curves from i n i t i a curve to maximum curve. determined by radiography however i t i s unethical to submit i n d i v i d u a l s to t h i s procedure for research purposes as w e l l as c o s t l y and unaccept-able to the population. Other st r a t e g i e s as suggested by Grant (1974) are a v a i l a b l e . For the purpose-of estimation of prevalence of adoles-cent i d i o p a t h i c s c o l i o s i s the studies of Rogala et a l . (1978), Brooks (1980) and Kane (1977b) were used to s e l e c t a prevalence of 2 percent. In a screening population of 8010 t h i s would suggest 160 cases of s c o l -i o s i s with an 11° curvature or greater. The f o u r f o l d table Table VII shows the figures for diseased p o s i t i v e , non-diseased p o s i t i v e and t o t a l p o s i t i v e from the screening program r e s u l t s . An adjustment to the diseased p o s i t i v e group was made to account for two c h i l d r e n who were screened and were othopedically p o s i t i v e but were already known and under physician observation. These two are screening p o s i t i v e because t h e i r curves have been accurately i d e n t i f i e d by the screening program. , TABLE VII FOURFOLD TABLE DERIVED USING PREVALENCE STATISTICS Diagnosis Screening r e s u l t s diseased non-diseased t o t a l P o s i t i v e 42 127 169 Negative 118 7723 7841 T o t a l 160* 7850 8010 *The 2 percent prevalence s t a t i s t i c (Rogala et a l . 1978) i s applied to the screening population, i . e . 8010 X .02 = 160. Chi Square with 1° of freedom = 69.8019 p<.01. By using the 2 percent prevalence c a l c u l a t i o n to estimate a t o t a l diseased population as 160, a diseased screening negative group of 118 can be derived. Estimates for non-diseased screening negative and t o t a l non-diseased then follow by addition or subtraction (see Chapter three, Fig.: 3, page 65) . From the derived f o u r f o l d table c e r t a i n estimations can now be made about the screening test (see formulae page 66). S e n s i t i v i t y O v e r a l l s e n s i t i v i t y - r | | X 100 = 26.2% ±ou For each of the years of the screening program s e n s i t i v i t y was calculated as: 1976-77 1977-78 1978-79 1979-80 S p e c i f i c i t y 3^ - X 100 = 32.7% •Jy X 100 = 37.8% T r X 100 = 14.7% 34 ~ X 100 = 10.8% 7721 J X 100 = 98.4% 7850 O v e r r e f e r r a l ( f a l s e p o s i t i v e s ) 127 X 100 = 75.1% 169 Underreferral ( f a l s e negatives) 118 7841 X 100 = 1.5% P o s i t i v e p r e d i c t i v e value 42 X 100 = 24.9% 169 O v e r a l l p r e d i c t i v e value 42 + 7723 8010 X 100 = 96.9% Prevalence of s c o l i o s i s at SFHD Comparison of the prevalence rate of s c o l i o s i s curves i d e n t i f i e d at SFHD with others i n the l i t e r a t u r e provides another measure of the v a l i d i t y of the screening test. Prevalence w i l l be discussed as pre-valence of curves 11° and greater and prevalence of treatable curves. Prevalence of curves 11° and greater was used to estimate the prevalence of s c o l i o s i s i n the population of SFHD screened between September 1976 and June 1980. The number of chi l d r e n i d e n t i f i e d as orthopedically p o s i t i v e , that i s with a curve 11° or greater on r a d i o -graphic examination (Cobb method of calculation) (N = 40) along with the t o t a l screening population of 8010 i s the basis of the c a l c u l a t i o n but two adjustments were made to r e f l e c t a more accurate prevalence f i g u r e . The 9 c h i l d r e n who were not screened because parents advised that they were under management for s p i n a l disease w i l l be considered as p o s i t i v e (although the true status of a l l cases i n terms of being 82 orthopedic p o s i t i v e i s not known) along with the 2 chi l d r e n who were screening p o s i t i v e and already known to the i r physicians as s c o l i o t i c s , for a t o t a l of 51 cases. The c a l c u l a t i o n for prevalence then i s X 100 = 0.636% or rounded to 0.6% The rate i s expressed as a percentage or per hundred to concur with the l i t e r a t u r e . The prevalence rate for each screening year with adjustment for other s c o l i o t i c s i s given i n Table VIII. TABLE VIII NUMBER AND RATE OF ORTHOPEDIC POSITIVES PER SCREENING YEAR year number screened orthopedic p o s i t i v e other % of t o t a l 1976-77 2587 17 0 0.66 1977-78 1873 14 5 1.0 1978-79 1690 5 3 0.47 1979-80 1860 4 3 0.38 To t a l 8010 40 11 0.636 In c i d e n t a l l y the prevalence rate was reported as 0.65 percent f o r the SFHD p i l o t project January to June 1976 (SFHD Report 1977). The prevalence of treatable curves i n the screening population i s suggested i n the l i t e r a t u r e (Rogala et a l . 1978) as 2.75 per thousand or 0.275 per hundred. At SFHD there have been 12 cases i n which active treatment was recommended (bracing and/or surgery). This includes those who rejected active treatment. The rate at SFHD for treatable curves i s 83 0.1498 per hundred or about one-half the rate found i n the study of Rogala et a l . (1978). This prevalence f i g u r e does not take into account the 11 presumptive cases i n the community that were added for c a l c u l a -t i o n of prevalence. If they were a l l a c t i v e l y treated the prevalence of treatable curves would be 1 2 ontn 1 1 x 1 0 0 = 0.287% which i s close to that of Rogala et a l . (1978) and the 0.3 percent reported by Moe et a l . (1978). I t i s known that 2 of the 11 had sur-gery for s c o l i o s i s and that 2 are under physician observation but the status of the other 7 i s unknown. A v a i l a b i l i t y of Resources The resources described are those which are u t i l i z e d i n the screening program and those which are required as a r e s u l t of screening. The a c c e s s i b i l i t y of services f o r follow-up of the screening r e f e r r a l s w i l l be reported and p a r t i c u l a r mention made of the orthopedic services. Screening program resources The data i n Table IX are from the annual reports written by the physiotherapists at SFHD. No figures were estimated i n 1978-79 screen-ing year. To complete the table therefore an estimate of resources used i n that year i s made. The cost per screenee i n 1977-78 was $2.07, i n 1979-80 i t was $2.19. If each of these costs i s m u l t i p l i e d by the number screened i n 1978-79 (1690) and averaged, the fi g u r e of $3599.70 could be considered an estimate for 1978-79 screening costs. Given that a l l hours of service are estimated there i s not a precise costing TABLE IX SFHD RESOURCES UTILIZED IN SCOLIOSIS SCREENING 1976-77 1977-78 1979-80 Total Cost number screened 2587 1873 1860 8010* time i n hours physiotherapy 400 ($8.5/h) 137 ($10/h) 107 ($12.8/h) 644 $3,400.00 $1,370.00 $1,369.60 $6,139.60 public health nursing 127 ($10/h) 146 ($10/h) 221 ($ll/h) 494 $1,270.00 $1,460.00 $2,431.00 $5,161.00 c l e r i c a l 32 ($6.8/h) 34 ($6.8/h) 29 ($7.3/h) 95 $217.60 $231.20 $211.70 $660.50 preparation of report 100 ($8.5/h) 55 ($10/h) 5 ($12.8/h) 160 $850.00 $550.00 $64.00 $1,464.00 evaluation study 28 ($10.7/h) 25 ($ll/h) 53 $299.60 $275.00 $5,746 medical health o f f i c e r 10 10 $200.00 $200.00 t o t a l hours 697 397 362 1456 t o t a l cost $6,237.20 $3,886.20 $4,076.30 $14,199.70 I f estimate of $3,599.70 i s used for 1978-79 t o t a l cost = $17,799 .40. *includes 1690 screened 1978-79. 85 for any year. In round figures f o r four years the cost of screening has been $17,800. Costs include s a l a r i e s of health d i s t r i c t personnel involved i n the program but excludes t r a v e l expenses, health d i s t r i c t o f f i c e overhead, c l e r i c a l service i n the schools, stationery and postage and cost of supplies such as t r a i n i n g manuals, texts and f i l m s . Cost of other services u t i l i z e d The number of services i n the categories of X-ray, family phy-s i c i a n , orthopedic s p e c i a l i s t , chiropractor, physiotherapy and bracing i s presented for the orthopedic p o s i t i v e cases i n Table X. Although s i x of these children required surgery, t h i s item i s not included as i t i s the writer's contention that surgery would have occurred eventually without screening, when the curve was noted by the family or physician and medical care commenced. The number of r e f e r r a l s seen by the general p r a c t i t i o n e r and the orthopedist and the X-ray status i s found i n Table XI. Of those 169 c h i l d r e n who were screening p o s i t i v e , 166 went to the family phy-s i c i a n who ordered X-rays for 39 percent of them. Thir t y - e i g h t c h i l -dren (24 percent) were pronounced normal on c l i n i c a l examination alone without X-ray. Some were not X-rayed by the general p r a c t i t i o n e r but referred d i r e c t l y to the orthopedic s p e c i a l i s t who X-rayed 74 percent of the ch i l d r e n seen by him. The cost of health care services which have been u t i l i z e d f o r the screening p o s i t i v e s of the program for the four years of the study are tabulated i n Table XII. The highest cost of any screening year occurred i n 1976-77, bracing was the most expensive service followed by TABLE X NUMBER OF SERVICES PROVIDED FOR ORTHOPEDIC POSITIVES 1976-77 1977-78 1978-79 1979-80 t o t a l Number of cases 17 - 5 4 40 Number of X-rays 48 35 11 7 98 V i s i t s to family physician 21 16 6 5 46 V i s i t s to orthopedic s p e c i a l i s t 80 49 19 13 158 Number of ch i r o p r a c t i c services 39 - 22 - 61 Number of physiotherapy services 169 34 14 4 221 Number of cases braced 1 2 2 1 6 Surgi c a l procedures 3 - 3 - 6 oo (-N TABLE XI NUMBER OF REFERRALS SEEN BY GENERAL PRACTITIONER AND ORTHOPEDIST AND X-RAY STATUS Year Number Referred To General P r a c t i t i o n e r X-ray Percentage To Orthopedist X-ray Percentage 1976-77 84 83 36 43% 44 34 77% 1977-78 42 41 17 41% 24 19 79% 1978-79 17 17 5 29% 12 7 58% 1979-80 26 25 6 24% 9 6 ' 67% Total 169 166 64 39% 89 66 74% Refused r e f e r r a l 2, Unknown 1. TABLE XII COST OF SERVICES* PROVIDED FOR ORTHOPEDIC POSITIVE (i n d o l l a r s ) SCREENEES 1976-77 1977-78 1978-79 1979-80 Tot a l Number of cases 17 14** 5 4 39 X-rays 795.60 647.40 204.80 148.10 1,795.90 Family physician 206.30 165.75 68.35 60.50 500.90 Orthopedic s p e c i a l i s t 1,351.75 1,006.68 412.30 317.30 3,088.03 Chi r o p r a c t i c 319.25 - 181.25 - 500.50 Physiotherapy 1,188.50 240.75 100.00 28.00 1,557.25 Bracing 1,600.00 900.00 1,300.00 1,000.00 4,800.00 To t a l 5,461.40 2,960.58 2,266.70 1,553.90 12,242.58 *Surgery not included as a cost of screening. **Costs are unknown for one case (braced). the cost of the orthopedic s p e c i a l i s t . The t o t a l cost was estimated at $12,242.58, excluding costs of surgery and h o s p i t a l i z a t i o n . The cost of screening must also include the costs to the health care system of those who were screening p o s i t i v e but ultimately diag-nosed as negative. The number of services f o r t h i s group i s presented i n Table XIII and the costs i n Table XIV. The t o t a l cost i s estimated at $6,324.63. The most c o s t l y service for the f a l s e p o s i t i v e s , which t h i s group constitutes, was for the orthopedic s p e c i a l i s t . A c c e p t a b i l i t y of follow-up services None of the f a m i l i e s expressed any d i f f i c u l t i e s i n obtaining appointments with physicians, e i t h e r family doctors or orthopedists. When an e a r l i e r review of the s c o l i o s i s program was done there were comments that the wait for orthopedic appointments was unduly long but th i s was not mentioned during any of the l a t e s t telephone interviews. X-ray ser v i c e s , physiotherapy and c h i r o p r a c t i c services were not men-tioned as causing any problem i n a v a i l a b i l i t y . The o r t h o t i c service has been an area of concern to those who required bracing during the period of t h i s study. At an early stage of t h i s screening program the service was provided at Shaughnessy Hosp i t a l . There was an i n t e r v a l of over a year when th i s o r t h o t i s t : from Shaughnessy who i s recognized as the p r o v i n c i a l expert on the Milwaukee brace was away. On his return o r t h o t i c service resumed through h i s p r i v a t e firm and h i s services are a v a i l a b l e at the weekly Children's H o s p i t a l s c o l i o s i s c l i n i c where the o r t h o t i s t i s part of the team evaluating and pre s c r i b i n g brace treatment. TABLE XIII SERVICES PROVIDED FOR ORTHOPEDIC NEGATIVE* SCREENEES '1976-77 '1977-78 Screening Year " 1978-79 -1979-80 i T o t a l Total Cases 65 27 9 20 121 X-rays 47 18 7 8 80 V i s i t s to family physician 118 48 18 27 211 V i s i t s to orthopedic s p e c i a l i s t 47 24 6 5 82 Chiropractic services 19 0 0 0 19 Physiotherapy v i s i t s 17 28 0 0 45 *does not include other s p i n a l diseases. o - TABLE XIV COST OF SERVICES FOR ORTHOPEDIC (in d o l l a r s ) NEGATIVE SCREENEES 1976-77 1977-78 1978-79 1979-80 T o t a l Number of cases 65 27 9 20 121 X-rays 749.90 328.90 90.90 156.20 1,325.90 Family physician 1,187.40 503.20 204.20 340.40 2,235.20 Orthopedic s p e c i a l i s t 1,280.87 660.82 157.14 196.40 2,295.23 Chiropractic 150.55 - - - 150.55 Phys iotherapy 121.75 196.00 - - 317.75 Tota l 3,490.47 1,688.92 452.24 693.00 6,324.63 92 Those c h i l d r e n from SFHD who were not r e f e r r e d to the s c o l i o s i s c l i n i c at Children's H o s p i t a l had a less coordinated approach to ortho-t i c treatment. The team of physiotherapist, orthopedic s p e c i a l i s t , o r t h o t i s t and child/parent was not involved i n p r e s c r i p t i o n and assess-ment. Of the s i x c h i l d r e n who were braced three had problems with t h e i r adjustment to the brace or i n obtaining a good co r r e c t i o n of t h e i r curves. Of the three s u c c e s s f u l l y braced one has been followed every three months at the Children's Hospital c l i n i c while the second c h i l d i s seen p r i v a t e l y with review by the orthopedist every three to four months with r e f i t t i n g of the brace as indicated. The d e t a i l s of the o r t h o t i c service received by the case l i v i n g out of B r i t i s h Columbia i s not known. Orthopedic services i n B r i t i s h Columbia In the l a t e s t Directory published by the College of Physicians and Surgeons of B.C. (1980) there are 108 orthopedic surgeons l i s t e d . Of the 108, 80 or 74 percent are located i n the Lower Mainland and Greater V i c t o r i a region. The population covered by these 80 orthoped-i s t s i s 1,372,002. The balance of the people i n B.C., 1,264,898, are located i n areas served by the 28 remaining orthopedic s p e c i a l i s t s . They are located as follows: Vancouver Island (except V i c t o r i a ) 7 Okanogan (Vernon, Kelowna, Penticton) 7 Fraser Valley 5 T r a i l 1 Nelson 1 Kamloops 3 Prince George 2 Dawson Creek 1 Kitimat 1 93 Population information was provided by Hospital Programs, Minis t r y of Health, V i c t o r i a (Selwood 1981). Surgery for s c o l i o s i s was performed on 84 people i n B.C. during the period A p r i l 1, 1979 to March 31, 1980. The following Table XV indicates by h o s p i t a l where surgeons performed surgery with the Harrington Rod and s p i n a l fusion (ICD code 930.4). Of the 84 opera-ti o n s , 82 (98 percent) were performed i n ho s p i t a l s i n the v i c i n i t y of Vancouver and V i c t o r i a . TABLE XV SURGERY WITH HARRINGTON ROD (ICN CODE 930.4) IN B.C. BY HOSPITAL APRIL 1, 1981 TO MARCH 31, 1980 Hospital T o t a l 0-14 15-44 45-69 70-Children's (Vancouver) 32 22 10 - -Royal Columbian (New Westminster) 7 2 4 1 — Royal Inland (Kamloops) 2 — — 2 — Royal Jubilee ( V i c t o r i a ) 4 2 2 — — Shaughnessy (Vancouver) 16 2 14 — — Surrey Memorial (Surrey) 3 — 3 Vancouver General (Vancouver) 19 9 10 — V i c t o r i a General (Vict o r i a ) 1 1 — — — T o t a l 84 38 43 3 — SOURCE: W. E. Selwood, Research D i v i s i o n , Hospital Programs, Mini s t r y of Health, V i c t o r i a , B.C. Interview, June 23, 1981. 94 CHAPTER V DISCUSSION In t h i s study evaluation of s c o l i o s i s screening at SFHD i s based on the a p p l i c a t i o n of established c r i t e r i a to the program r e s u l t s and on the evidence i n the l i t e r a t u r e about s c o l i o s i s . A l l twelve c r i t e r i a i d e n t i f i e d i n the l i t e r a t u r e review w i l l be used but four p r i n c i p a l c r i t e r i a were chosen as of s p e c i a l s i g n i f i c a n c e on the basis of data av a i l a b l e and the l i m i t s of time and resources for t h i s study. These four c r i t e r i a are: 1) a c c e p t a b i l i t y of the screening test 2) a c c e p t a b i l i t y of treatment 3) v a l i d i t y of the test 4) a v a i l a b i l i t y of resources Before r e l a t i n g the r e s u l t s of t h i s study to these p r i n c i p a l c r i t e r i a there w i l l be a b r i e f discussion of the s i g n i f i c a n c e of the remaining c r i t e r i a to the evaluation of t h i s s c o l i o s i s screening program. Appli c a t i o n of General C r i t e r i a  Importance as a health problem The c r i t e r i o n that s c o l i o s i s must be an important disease to j u s t i f y screening has not been f u l f i l l e d . Data on morbidity and mor-t a l i t y due to s c o l i o s i s i n the population i s l i m i t e d . The s t a t i s t i c s for the seven years from 1972-78 revealed 2 deaths i n B.C. and 24 i n Canada due to s c o l i o s i s , an i n s i g n i f i c a n t number. V a l i d morbidity s t a -t i s t i c s are not a v a i l a b l e but there are some reports i n the l i t e r a t u r e which discuss d i s a b i l i t y and death due to s c o l i o s i s . Reports of back pain, dyspnea and premature death range from normal ( C o l l i s and Ponseti 1968) to notably higher (Nilsonne and Lungren 1968) i n untreated s c o l -i o s i s p atients. In the sphere of s o c i a l e f f e c t mention i s made of fewer marriages, embarrassment about appearance and s o c i a l i s o l a t i o n among s c o l i o t i c s . Information regarding the degree of curvature, type of s c o l i o s i s and prevalence of the d i s a b i l i t y are a l l necessary to ev a l -uate the reported e f f e c t s of s c o l i o s i s and are not always a v a i l a b l e to a s s i s t i n reaching a conclusion about the s i g n i f i c a n c e of the disease. Accepted ( E f f e c t i v e ) treatment The l i t e r a t u r e survey found that the e f f i c a c y of treatment for s c o l i o s i s has not been assessed by eit h e r randomized c l i n i c a l t r i a l or a t r i a l of quasi-experimental design. The d e s c r i p t i v e evidence about treatment from t h i s study i s not conclusive. In the study sample s i x ch i l d r e n were braced; treatment was unsuccessful i n three cases and i t would be premature to c a l l the three remaining cases successful. Outcome of surgery i n the s i x cases has appeared to be successful, although one g i r l requires a second operation to modify the Harrington Rod because of discomfort. This i s reported to be a minor procedure. This study has not attempted to evaluate the e f f i c a c y of physio-therapy treatment but i n view of the reported lack of e f f i c a c y of exer-c i s e as a treatment for s c o l i o s i s the use of physiotherapy as sole treatment i n ten cases was a questionable p r a c t i c e . 96 A c c e p t a b i l i t y of treatment which was considered along with e f f i c a c y as a component of the effectiveness of treatment w i l l be con-sidered as one of the four p r i n c i p a l c r i t e r i a . Recognized l a t e n t stage and known natural h i s t o r y From what i s written about s c o l i o s i s there may be a recognizable lat e n t or early symptomatic stage but i t i s not yet clear which curves w i l l progress from t h i s stage. There i s promise that evaluative studies now possible because of widespread screening i n early adolescence w i l l shed l i g h t on the natural h i s t o r y of s c o l i o s i s including the lat e n t period. The evidence to date from prospective studies suggests that some curves improve, many remain unchanged and about three per thousand progress to what i s c a l l e d a treatable curve. In t h i s study sample none of the curves (N = 25) which were below 20° i n i t i a l l y progressed to a treatable curve. In those i n i t i a l l y 20° and above (N = 13), 77 percent (N = 10) progressed or required immediate treatment. Of those followed by X-ray (N = 10) i n the 20° and over group 80 percent progressed com-pared to 20 percent i n the under 20° category (5 of 24). These findings could have implications f or modifying the screening test so that fewer i n s i g n i f i c a n t curves ( i . e . below 20°) are re f e r r e d . Whom to treat as a patient The issue of who to treat as a s c o l i o s i s patient may be somewhat confusing u n t i l the upper range of curvatures i s reached. There i s general agreement that curves over 50° require surgery, those between 40° to 50° are debatable, and that for curves between 30° and 40° bracing i s the most desirable treatment f o r the majority of cases. Curves between 20° and 30° are usually cosmetically acceptable and Rogala et a l . (1978) found that one i n f i v e i n t h i s range i n an immature female did not progress so that bracing should not be applied r o u t i n e l y . Instead i t was suggested waiting f o r signs that the curve was. progres-sing before bracing. Kane (1977b) has defined the population at r i s k for s c o l i o s i s as those with curves 11° and over. Taylor et a l . (1978a) suggests there i s no sound agreement for management of curves under 25° and Howell and Craig (1980) suggest 15° curves are the ones to aim at i d e n t i -f y i n g . This screening program using 11° and over as the l e v e l of s i g n i -ficance had a p o s i t i v e p r e d i c t i v e power of about 25 percent, which means one out of four p o s i t i v e s was t r u l y p o s i t i v e . The question occurs that i f a curve was considered s i g n i f i c a n t only i f i t was 20° or over and the screening procedure was geared to detection of that range of curvature, would a better program result? Bone age appears to be the c r i t i c a l f a c t o r . Unless the i n d i v i -dual has growth p o t e n t i a l bracing w i l l not be e f f e c t i v e . Bracing can not be r e l i e d on to correct a curve but i t may arrest the progress of a curve during the balance of the growth period. I f bone age i s t h i s important f o r proper curve management, lack of an X-ray would appear to be a major d e f i c i t i n diagnosis and treatment of s c o l i o s i s . Of the screening p o s i t i v e s i n t h i s study 38 (24 percent) did not receive X-rays. The presumption i s that there was lack of c l i n i c a l evidence of s c o l i o s i s upon examination by the physician to warrant exposure to r a d i a t i o n . It i s also presumed that these p o t e n t i a l p o s i t i v e s were examined by physi-cians cognizant of the early c l i n i c a l signs of scoliosis:. No further 98 rechecks were done by the health d i s t r i c t screening team following the physician's report of negative findings unsupported by X-ray. Economic balance The c r i t e r i a suggesting economic balance i n the cost of case-fin d i n g i n r e l a t i o n to t o t a l medical expenditures i s not answered i n the l i t e r a t u r e or i n t h i s study. While there has been some e f f o r t to estimate d i r e c t costs, i n d i r e c t costs f o r anxiety, time l o s t and for health d i s t r i c t overhead costs (for example, telephone, o f f i c e , films and books, postage) are not estimated. There i s the opportunity to examine the medical expenditures which have resulted from the screening program i n terms of the follow-up of both orthopedic p o s i t i v e and negative screenees. Total estimated costs of $18,567.21 (Table XII and XIV) should be considered as a minimal fig u r e which does not include the cost of the s i x s u r g i c a l procedures which resulted from the r e f e r r a l s of the program. It i s considered that these operations would have occurred regardless of the screening program. They have occurred e a r l i e r and with presumably better r e s u l t s , a benefit which has not been measured at t h i s time. Costs for one of the braced children treated i n the U.S.A. were not estimated. An i n t e r e s t i n g aspect of cost i s that many ch i l d r e n pronounced as negative continue to be followed. In a North Vancouver study (1981) of 111 chil d r e n physicians categorized as normal i t was reported that 39 would continue to be followed by the private physician. The cost of continued s u r v e i l l a n c e should be evaluated i n terms, of eventual returns. An i n i t i a l diagnostic X-ray as recommended at SFHD should mean that only those curves "at r i s k " for progression are followed. Continuous case-finding The c r i t e r i a that case-finding should be continuous throughout an i n d i v i d u a l ' s period of " r i s k " i s more applicable to other types of screening than to s c o l i o s i s . In the case of s c o l i o s i s i t appears gen-e r a l l y acceptable to screen at a stage of adolescence when growth i s a c t i v e and early s c o l i o t i c curves are v i s i b l e . Ages of 12 to 14 have been considered most s u i t a b l e . Rogala's (1978) study in v o l v i n g a sample tested at an e a r l i e r age found no ben-e f i t . From the l i t e r a t u r e i t would appear that screening every c h i l d once during the age represented i n grade seven i s adequate. In respect to continuity of a screening program SFHD has had a continuous program for f i v e years. Cost-benefit and cost-effectiveness The c r i t e r i a c a l l i n g for knowledge of cost-benefit, cost-effectiveness have not been met i n studies i n the l i t e r a t u r e or by t h i s study. The SFHD program l i k e a l l others described i n the l i t e r a t u r e searched does not oontain a mechanism for weighing costs against ben-e f i t s and because of the long-term nature of the condition economic analysis would be complex. Estimation of s o c i a l benefits Estimation of s o c i a l benefits i n terms that withstand s c i e n t i -f i c scrutiny i s not possible from the l i t e r a t u r e or t h i s study. The 100 population i n the studies which describe the s o c i a l costs of s c o l i o s i s are not representative populations and control groups have not been used. Evaluation by P r i n c i p a l C r i t e r i a A p p l i c a t i o n of the four c r i t e r i a to the r e s u l t s of screening at SFHD w i l l now be discussed. A c c e p t a b i l i t y of screening test At SFHD the s c o l i o s i s program has been very well accepted by parents, c h i l d r e n screened and physicians. The r e f u s a l rate for i n i -t i a l screening (21/8031) of 0.3 percent i s i n d i c a t i v e of t h i s accep-t a b i l i t y . The use of a r e f u s a l only consent however may contribute to th i s high l e v e l of acceptance. I t should be recognized that a l l notices of screening do not reach home. In one telephone interview by this investigator i t was volunteered by the parent that no notice had been received. The c h i l d i n t h i s case had Marfan's syndrome with secondary s c o l i o s i s and the mother would have refused permission i f she had known of the program. In an e a r l i e r study at SFHD (Ladner 1978) 3 of 29 (10 percent) stated that they had not received the introductory l e t t e r . In the telephone interviews conducted by th i s investigator there were many voluntary expressions of appreciation for the screening pro-gram. In several cases these were by parents who had ch i l d r e n with no confirmed s c o l i o t i c disease but who had been referred for orthopedic consultation including X-rays. There appeared to be no resentment created by t h i s process. S p e c i f i c opinions about a c c e p t a b i l i t y of the program were not s o l i c i t e d from parents or physicians. 101 The self-consciousness of the screenees has been a minor d i f f i -c u l t y but not a drawback to screening i n terms of r e f u s a l to consent by the screenee. As the program has developed the s t a f f have devised ways to i n t e r p r e t the program and deal with the screenee i n an assured matter-o f - f a c t manner which has minimized the insecure reactions of the adol-escents. A c c e p t a b i l i t y i n the school d i s t r i c t s among p r i n c i p a l s , teachers, trustees and parents has been reported favorably throughout the screening period. The possible c a n c e l l a t i o n of the program i n the f a l l of 1980 because of shortage of physiotherapy s t a f f was greeted with consterna-t i o n by those i n the community who were aware of the p o s s i b i l i t y , i ncluding members of the Union Board of Health. This points out the i m p l i c a t i o n f or a health d i s t r i c t p ublic r e l a t i o n s e f f o r t i f the program i s modified or deleted i n the future. Physician acceptance has also been demonstrated by an e a r l i e r small survey and at present by the cooperation received by t h i s inves-t i g a t o r during t h e i r study. A c c e p t a b i l i t y of treatment To be e f f e c t i v e a treatment must be e f f i c a c i o u s or do more good than harm to those who f u l l y comply with i t s recommendations. As well as e f f i c a c y , effectiveness has another component, that of acceptance of the treatment by those to whom i t i s offered. This aspect of effectiveness of treatment can be considered i n r e l a t i o n to the numbers of known r e f u s a l s to comply with recommended treatments as w e l l as r e f u s a l s to accept r e f e r r a l to the physician (either general p r a c t i t i o n e r or s p e c i a l i s t ) . The r e f u s a l of 2 of 169 r e f e r r a l s for a rate of 1.2 percent indicates a high compliance rate compared to others reported i n the l i t e r a t u r e . Compliance with the recommendations of the family physician for continued observation was 95 percent. The l e v e l of compliance with the recommendation of the ortho-pedic s p e c i a l i s t was 73 percent considering r e j e c t i o n of any of the recommendations of t h i s physician as non-compliance. In 68 percent (15 of 22 ) of the instances the non-compliance was with the recommen-dation to return for a further examination. In the majority of these cases there had been no s i g n i f i c a n t progress of the curve to that point. In four cases there was f a i l u r e to accept the recommendation for brace treatment (three outright r e f u s a l s , one a f t e r r e c e i v i n g her brace). For the orthopedic p o s i t i v e s (N = 40) th i s i s a rate of 10 percent and 44.4 percent of those for whom bracing was recommended (N = 9). This in d i c a t e s a questionable l e v e l of a c c e p t a b i l i t y of bracing and i s s i g -n i f i c a n t because the primary goal of the screening program was to apply bracing as an a l t e r n a t i v e to surgery. The recommendation f o r surgery has been rejected by three g i r l s (N = 9). In one of the these cases the g i r l continues under chiroprac-t i c care and i s occasionally seen by the general p r a c t i t i o n e r who reports a curve of 38° which i s d i s f i g u r i n g but apparently acceptable , to the g i r l (now 17) and her parents. V a l i d i t y of the test V a l i d i t y of the screening test i n use at SFHD has been assessed 103 i n terms of how w e l l the r e s u l t s of screening have related to the diag-n o s t i c measure. The s e n s i t i v i t y of the screening test was 26.2 percent over the four years of the program. When i t was calculated on a yearly basis the range was from a high of 38 percent i n 1977-78 to a low of 11 per-cent i n 1979-80. This s e n s i t i v i t y i s unacceptably low. At least a 75 percent minimal l e v e l of s e n s i t i v i t y should be reached (Howell et a l . 1978). Of p a r t i c u l a r i n t e r e s t i s the s i g n i f i c a n c e of the trend to lower s e n s i t i v i t y which may have indicated d e c l i n i n g screen competency. Although over 70 percent of the c h i l d r e n with 11° or greater s c o l i o t i c curves apparently were missed by t h i s screening i t must be remembered that s c o l i o s i s i s also i d e n t i f i e d by the observations of others and also that many curves are not s i g n i f i c a n t health problems so that mis-sing them i s not as c r i t i c a l as would be the case i n screening for other diseases more l i f e - t h r e a t e n i n g . The s p e c i f i c i t y of the screening test i s 98.4 percent which meets the c r i t e r i o n of Howell et a l . (1978) of at least 95 percent. The 127 f a l s e p o s i t i v e s which give an o v e r r e f e r r a l rate of 75.1 percent i s a concern because of the resources used i n unnecessary diag-n o s t i c t e s t i n g and possibly treatment as w e l l as the anxiety generated and the time l o s t i n the process of needless follow-up. There are probably two reasons why o v e r r e f e r r a l was not creating d i f f i c u l t i e s i n the health d i s t r i c t . F i r s t there were no d i r e c t c l i e n t costs because of the Medical Services Plan and second, physicians were i n ample supply and r e a d i l y a v a i l a b l e . In considering t h i s high f a l s e p o s i t i v e rate i t may be useful to r e c a l l that when a disease i s infrequent i n the population-like s c o l i o s i s - even a screening test with high s p e c i f i c i t y (and the rate i s 98.4 percent) w i l l y i e l d a high percentage of f a l s e p o s i t i v e s (Friedman 1974). I t should also be noted that Wilson and Jungner advised that a f a i r l y high f a l s e p o s i t i v e rate i s acceptable but the f a l s e negative rate should be low. A f a l s e p o s i t i v e rate of 75.1 percent appears more than " f a i r l y high" however. The costs of o v e r r e f e r r a l for four years of screening are estimated at $6,324.63, which i s not a formidable sum i n terms of other health care program costs. Underreferrals are calculated at 1.5 percent. This represents the missed cases. I t has been suggested that an underreferral rate of les s than 5 percent i s sometimes considered an acceptable percentage of f a l s e negatives (Stangler et a l . 1980). The p o s i t i v e p r e d i c t i v e power i s the fi g u r e of i n t e r e s t to physicians who see r e f e r r a l s as i t represents the proportion of true cases they might expect to see i n the c h i l d r e n r e f e r r e d to them. I t was 24.9 percent for the screening program at SFHD, which meant that three out of four times the r e f e r r a l was needless. However, the o v e r a l l  p r e d i c t i v e v a l i d i t y of the screening test was 97 percent, an acceptable fig u r e i n d i c a t i n g 97 out of every 100 c h i l d r e n were c o r r e c t l y i d e n t i -f i e d by the screening process. This screening test has i d e n t i f i e d a sample of orthopedically p o s i t i v e c h i l d r e n i n a sex d i s t r i b u t i o n s i m i l a r to that reported i n the l i t e r a t u r e . The f i n d i n g that the r a t i o i s 1:9 (male to female) has implications for program modification. None of the treatable curves have occurred i n males i n four years of screening a population of 8010 c h i l d r e n . In other areas such as Edmonton, g i r l s only are screened. A s i m i l a r approach could be considered i n SFHD, e f f e c t i v e l y halving the population to be screened. The SFHD screening program has not found the number of ortho-p e d i c a l l y p o s i t i v e screenees which would be expected from published prevalence figures i n s i m i l a r screening populations. The rate of 0.6 percent i s much lower than that found i n Vancouver's p i l o t program (Hornung 1977) which reported a rate of 4 percent (41 i n 1006). Con-trasted to the major study i n Montreal (Rogala et a l . 1978) where 2 percent of the screened population had curves greater than 10°, SFHD's prevalence i s notably low. The prevalence of treatable curves i n the study population at a rate of 0.1498 percent or about one-half the pre-valence expected (0.275 or 0.3 percent) i s another questionable f i n d i n g but must be viewed with caution because of the unknown treatment status of other s c o l i o s i s curve cases i n the community. The concern i s of course that curves that are most "at r i s k " , with p o t e n t i a l f o r preventive treatment are being missed. A v a i l a b i l i t y of resources There i s no question that the existence of t h i s screening pro-gram at SFHD has taken a considerable portionof health d i s t r i c t s t a f f time (see Table IX) as w e l l as using other community health services such as general physician, orthopedist, X-ray and physiotherapy (Tables X, XII, XIII and XIV). There has been no apparent problem i n meeting the demand f o r these se r v i c e s . The question of costs generated and a l t e r n a t i v e s foregone has not been evaluated. The health d i s t r i c t at the present time has begun 106 the process of zero-based budgeting., In preparation for t h i s each pro-f e s s i o n a l group i n the health d i s t r i c t i s i d e n t i f y i n g program p r i o r i t i e s and the minimal l e v e l s of service which must be provided. The figures on s t a f f time spent i n s c o l i o s i s screening w i l l be useful i n t h i s pro-cess of choosing between a l t e r n a t i v e programs. The one apparent de f i c i e n c y i d e n t i f i e d has been lack of a cen-t r a l c l i n i c to receive r e f e r r a l s f o r a l l screening p o s i t i v e s . Such a c l i n i c would enable outcomes to be r e a d i l y a v a i l a b l e for the monitoring of screening v a l i d i t y . S t a f f t r a i n i n g i n screening would be f a c i l i t a t e d by a c l i n i c where orthopedic p o s i t i v e s could be seen c l i n i c a l l y . The follow-up of p o s i t i v e s could be ensured with a call-back system. Proper diagnostic X-rays would be assured. If treatment were also handled i n a c l i n i c approach more successful bracing treatment could be possible. In t h i s way some group support for those re q u i r i n g bracing could be used to help the bracing candidate work through her acceptance of the treatment. The area of orthosis i s the one of most concern. At the present time t h i s s ervice f o r the f i t t i n g of the Milwaukee brace i s a v a i l a b l e from a c e r t i f i e d o r t h o t i s t i n Vancouver. During the period covered by t h i s study there were gaps i n o r t h o t i c service offered. As o r t h o t i c s for s c o l i o s i s appears to be highly s p e c i a l i z e d and 90 percent of the c h i l d r e n i n B.C. come to t h i s one o r t h o t i s t i n Vancouver, one might question the problem generated i f more bracing treatment r e s u l t s from expanded screening e f f o r t s should the program become provincewide. The same problem could be created through deficiency i n ortho-pedic expertise i n s c o l i o t i c treatment. P e d i a t r i c orthopedists are 107 rare (3 of 108 p r a c t i c i n g orthopedists i n B.C.) and these are located i n the Lower Mainland and V i c t o r i a areas so that considerable d i f f i c u l t y could be generated f o r patients throughout the province seeking a con-s u l t a t i o n . The l e v e l of expertise i n diagnosis of s c o l i o s i s f or the average family physician i s unknown. In the SFHD program many of the general p r a c t i t i o n e r s referred the c h i l d d i r e c t l y to an orthopedist without X-ray examination i n s p i t e of the health d i s t r i c t ' s recommenda-ti o n contained i n the l e t t e r of r e f e r r a l . In some cases no p h y s i c a l examination was done e i t h e r , which would i n d i c a t e some questionable physician confidence i n t h i s area. 108 CHAPTER VI CONCLUSION As Chamberlain has said so aptly i n h i s paper on evaluation of screening: The decision on whether or not to provide a screening service to control one or more diseases can seldom be an easy one for the health administrator. He not only has to devise an e f f i -cient method of organization within the e x i s t i n g health care system, but he also has to measure the t o t a l cost of t h i s and decide whether the extent of benefit l i k e l y to be achieved i s greater than that which could be derived from a l t e r n a t i v e ways of spending h i s scarce resources. To make t h i s decision r a t i o n -a l l y requires a s c i e n t i f i c evaluation of screening and early treatment, taking into account a l l the factors which can i n f l u -ence i t s success. (Chamberlain 1979, p. 757) The same challenge confronts the health administrator i n deciding whether a program should be continued. In an e f f o r t to provide a r a t i o n a l basis f o r program planning at SFHD c r i t e r i a were applied to the s c o l i o s i s screening program and the r e s u l t s from that program for the 8010 c h i l d -ren screened from September 1976 to June 1980. The following hypothesis was proposed for the study: Evaluation of the r e s u l t s of four years of s c o l i o s i s screening  at Simon Fraser Health D i s t r i c t w i l l substantiate continuation of the  screening program. The conclusion that the evidence does not support program con-t i n u a t i o n i s reached on the following b a s i s . F i r s t , the o r i g i n a l program objective of i d e n t i f i c a t i o n of s c o l -i o t i c curves at a stage when the Milwaukee brace could be applied and 109 surgery avoided, has not been achieved. Six operations for s c o l i o s i s have occurred i n the screening population. In f i v e of these s i x cases bracing was either unsuccessful or unacceptable and thus did not prevent the surgery. The c r i t e r i o n of acceptability of the screening test has been well met at SFHD. The screening test has been highly acceptable to parents and children with few exceptions. The refusal rate was e s t i -mated at 0.3 percent however i t i s recognized that a l l parents were not aware of the screening date to offer dissent because notices had not been received. This has not been a problem and this highly v i s i b l e program i s also well-supported by school d i s t r i c t personnel, the Union Board of Health and personnel of the health d i s t r i c t . The evidence from this study suggests that the c r i t e r i o n that a screening program should be offered only i f acceptable treatment i s available to those who require i t , has not been f u l f i l l e d . Active treatment for s c o l i o s i s i s recognized as bracing or surgery. In th i s screening population bracing was recommended for nine children and was refused i n three cases. Another c h i l d rejected the brace immediately after receiving i t . E s s e n t i ally then four of the nine (44.4 percent) candidates for bracing did not accept this treatment. Surgery was recommended for nine children and i n three cases (33.3 percent) t h i s recommendation was not accepted. The c r i t e r i o n that the screening test i s v a l i d may be assessed by the l e v e l of s e n s i t i v i t y and s p e c i f i c i t y achieved by that test as well as overreferral and underreferral rates and the predictive value of the test. A s e n s i t i v i t y of 26.2 percent was derived using s c o l i o s i s 110 prevalence from the l i t e r a t u r e to give a " t o t a l diseased" estimate for the f o u r f o l d table. Using t h i s standard only one c h i l d i n four with s c o l i o s i s i s recognized i n th i s screening program. S p e c i f i c i t y was estimated at 98.4 percent, underreferral at 1.5 percent and t o t a l pre-d i c t i v e value at 96.9 percent. While s p e c i f i c i t y , underreferral and o v e r a l l p r e d i c t i v e value are acceptable, the 75.1 percent rate f o r over-r e f e r r a l i s a concern because of the d i r e c t costs generated i n unneces-sary diagnostic and possibly treatment services. Indirect costs of o v e r r e f e r r a l are harder to estimate but do occur because of anxiety and time loss and possibly due to unnecessary exposure to r a d i a t i o n . Published prevalence figures of 2 percent to 4 percent using the same age group, screening t e s t and diagnostic standard have been widely reported. Prevalence of s c o l i o s i s at SFHD was estimated at 0.6 percent f o r the four years of the program under review. In s p i t e of adjustments made to account for known s c o l i o s i s i n th i s population apart from the screening sample, t h i s low figu r e c a l l s into question the v a l i d i t y of the screening t e s t . Socio-economic, ethnic differences or other v a r i a b l e s were not apparent between SFHD's population and those with the higher prevalence. This study has not attempted to explore the reasons for the i d e n t i f i c a t i o n of fewer true p o s i t i v e s i n t h i s screening population. The l a s t c r i t e r i o n applied to SFHD's program was that resources were av a i l a b l e to carry out the program and to treat cases found by screening. While provision of s t a f f f o r screening can be a major resource problem there has been no evidence that this was a d i f f i c u l t y during the period of this study apart from a b r i e f period when the I l l d i s t r i c t was without two physiotherapists. As the health d i s t r i c t examines i t s p r i o r i t i e s under a new system of f i s c a l management the p r i o r i t y given to s c o l i o s i s screening i s being reassessed. The e s t i -mates of s t a f f time and cost w i l l have a place i n t h i s assessment. The aspect of the c r i t e r i o n that a v a i l a b l e resources for t r e a t -ment be a v a i l a b l e i s questionable i n two areas. F i r s t , the absence of a c l i n i c for r e f e r r a l of a l l screening p o s i t i v e s has been a disadvan-tage i n the operation of t h i s screening program and i n i t s continuing evaluation. Such a resource would have enabled the screening program to be monitored, ensured standard X-rays necessary f o r accurate diag-nosis of s c o l i o s i s , and been a resource for t r a i n i n g screening person-n e l . Second, o r t h o t i c service has been an area of concern during the four years of the screening program. There were periods when exper-ienced o r t h o t i c service was not a v a i l a b l e . In the long term t h i s may have detracted from bracing as a treatment a l t e r n a t i v e . In summary, continuation of the s c o l i o s i s screening program i s not supported because although the screening test and program have been acceptable, the a c c e p t a b i l i t y of treatment by bracing and surgery i s questionable. The low s e n s i t i v i t y and high o v e r r e f e r r a l rate of the screening test c a l l i nto question i t s v a l i d i t y . The c r i t e r i o n of a v a i l a b l e resources i s not f u l f i l l e d because of lack of coordinated o r t h o t i c services and a c l i n i c for r e f e r r a l of screening p o s i t i v e s for diagnosis and treatment. General Recommendations Because the hypothesis of t h i s study has not been supported i t i s recommended that the s c o l i o s i s screening program at SFHD be discontinued. 112 This decision i s r a t i o n a l i z e d by review of the r e s u l t s of the program using the four p r i n c i p a l evaluative c r i t e r i a of screening and by the lack of evidence that other c r i t e r i a to v a l i d a t e screening are f u l f i l l e d . The introduction of the s c o l i o s i s screening program to other p r o v i n c i a l health d i s t r i c t s would not appear advisable because of the concerns evidenced i n t h i s study about a c c e p t a b i l i t y of the treatment and v a l i d i t y of the screening t e s t . Even more important i f screening were extended into the p r o v i n c i a l system, would be the f u l f i l l m e n t of the c r i t e r i o n of a v a i l a b l e resources. The p r o v i n c i a l d i s t r i b u t i o n of orthopedic s p e c i a l i s t s and o r t h o t i s t s i s unequal, and considerable f r u s t r a t i o n and anxiety as w e l l as cost could be created by o f f e r i n g a program with the p o t e n t i a l f or a high rate of o v e r r e f e r r a l . In the event of discontinuation of the program the r a t i o n a l e should be interpreted c a r e f u l l y to the health d i s t r i c t s t a f f , school d i s t r i c t personnel, physicians and general p u b l i c . The high v i s i b i l i t y and wide acceptance of the program warrant a c a r e f u l l y planned public r e l a t i o n s e f f o r t . As an a l t e r n a t i v e p h y s i c a l education teachers of the d i s t r i c t should be taught about s c o l i o s i s and the signs of the condition so that obvious curves may be referred to the public health.nurse. This group of teachers see adolescents i n gym c l o t h i n g and bathing s u i t s r e g u l a r l y and so are most l i k e l y to detect obvious signs of a s c o l i o t i c curve such as unequal shoulder and hip l e v e l s , unequal waist angles, r i b humps, a t i l t e d p e l v i s and a curved s p i n a l column i n the normal course of t h e i r duties. I t i s not intended that they screen per se but that they r e f e r apparent problems. 113 In the event that the decision i s made to continue the screening program two recommendations are made. F i r s t that the screening of g i r l s only would reduce the time and cost of the program with n e g l i g i b l e e f f e c t on the number of treatable cases detected. Second, the establishment of a c e n t r a l c l i n i c f o r r e f e r r a l of a l l screening p o s i t i v e s should be a contingency of program continuation with the proviso that screening r e s u l t s w i l l meet set evaluative c r i t e r i a or the program w i l l be d i s -continued. Recommendations f or Further Study Evaluative studies of the screening test for s c o l i o s i s have been c a r r i e d out i n other parts of Canada. Consideration may be given to carrying out a study of the v a l i d i t y and r e l i a b i l i t y of the screening test using SFHD s t a f f and selected school c h i l d r e n . There i s a v a i l a b l e known X-ray status of a sample of chi l d r e n i n the d i s t r i c t to f a c i l i t a t e such a study. The status of c h i l d r e n who were screening p o s i t i v e but who were c l a s s i f i e d as normal without radiographic evidence by the physician should be investigated to determine t h e i r present c l i n i c a l status. A v a i l a b i l i t y of the radiographic status of these 38 screening p o s i t i v e s could e f f e c t the estimation of s e n s i t i v i t y of the screening t e s t . A study should be done on why bracing has not been acceptable to the ch i l d r e n who rejected t h i s form of treatment i n th i s program. Such a study w i l l be us e f u l i n the future approach to bracing as an acceptable treatment. Because of the small number a v a i l a b l e at SFHD the study could involve c h i l d r e n from other areas. And f i n a l l y . a study of the status of the screening r e f u s a l s would be h e l p f u l i n a r r i v i n g at a more accurate prevalence rate f o r s c o l i o s i s i n SFHD. Some of th i s group indicated s p i n a l disease as the reason for r e f u s a l and i t would be pertinent to know how many were i d i o p a t h i c s c o l i o s i s with an 11° or greater curvature. 115 LIST OF REFERENCES Blount, Walter P. 1981. The v i r t u e of early treatment of Idiopathic S c o l i o s i s . J . Bone J o i n t Surg. 63A: 335-336. Brooks, H. L. 1977. Idiopathic s c o l i o s i s - r e s u l t s of a prospective study. In S c o l i o s i s : proceedings of a f i f t h symposium, pp. 11-30. Edited by P. A. Zorab. London: Academic Press. Brooks, H. L. 1980. Current incidence of s c o l i o s i s i n C a l i f o r n i a . In S c o l i o s i s 1979, pp. 7-11. Edited by P. A. Zorab and D. S i e g l e r . London: Academic Press. Brooks, H. L.; Azen, S. P.; Gerberg, E.; Brooks, R.; and Chan, L. 1975. S c o l i o s i s : a prospective epidemiological study. J. Bone Joi n t  Surg. 57A: 968-972. Chamberlain, J . 1979. Evaluation of screening procedures. 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S c o l i o s i s prevalence: a c a l l for a statement of terms. C l i n . Orthop. 126: 43-46. Kane, William J.; Brown, John C.; Hensinger, Robert N.; and K e l l e r , Robert B. 1978. S c o l i o s i s and school screening for s p i n a l deformity. Am. Fam. Physician 17: 123-127. Keim, Hugo A. 1978. S c o l i o s i s . C l i n . Symp. (Ciba) 30: 1-30. Ladner, Dorothy. 1978. S c o l i o s i s screening: home v i s i t s to explore community reaction. Simon Fraser Health Unit, May, 1978. (Typewritten.) Lonstein, John E. 1977. Screening for s p i n a l deformities i n Minnesota schools. C l i n . Orthop. 126: 33-42. Lonstein, John E.; Winter, R. B.; Moe, J. H.; Bianco, A. J . ; Campbell, R. G.; and Norval, M. A. 1976. School screening f o r early detection of spine deformities. Minn. Med. 59: 51-57. McKeown, Thomas. 1968. V a l i d a t i o n of screening procedures. In Screening i n medical care: reviewing the evidence: a  c o l l e c t i o n of essays, pp. 1-13. N u f f i e l d P r o v i n c i a l Hospitals Trust. London: Oxford University Press. McKeown, T., and Knox, E. G. 1968. The framework required for v a l i d a t i o n of p r e s c r i p t i v e screening. In Screening i n medical  care: reviewing the evidence: a c o l l e c t i o n of essays, pp. 159-173. N u f f i e l d P r o v i n c i a l Hospitals Trust. London: Oxford U n i v e r s i t y Press. Mellencamp, David D.; Blount, Walter P.; and Anderson, A l f r e d J. 1977. Milwaukee brace treatment of i d i o p a t h i c s c o l i o s i s . C l i n .  Orthop. 126: 47-57. Moe, J. H. 1980. The Milwaukee brace i n the treatment of i d i o p a t h i c s c o l i o s i s . In S c o l i o s i s 1979, pp. 85-90. Edited by P. A. Zorab and D. S i e g l e r . London: Academic Press. 118 Moe, John H., and Kettleson, David N. 1970. Idiopathic s c o l i o s i s : Analysis of curve patterns and preliminary r e s u l t s of Milwaukee brace treatment i n 169 patients. J. Bone J o i n t Surg. 52A: 1509-1533. Moe, John H.; Winter, Robert B.; Bradford, David S.; and Lonstein, John E. 1978. S c o l i o s i s and other s p i n a l deformities. P h i l a d e l p h i a : Saunders. Nachemson, A l f . 1968. A long term follow-up study of non-treated s c o l i o s i s . Acta Orthop. Scand. 39: 466-476. Nilsonne, U l f , and Lundgren, Karl-David. 1968. Long-term prognosis i n id i o p a t h i c s c o l i o s i s . Acta Orthop. Scand. 39: 456-465. North Shore Health Department. 1981. S c o l i o s i s Screening Program 1979-1980. North Vancouver, B.C., March 1981. (Typewritten.) Per i o d i c Health Examination. 1980. Report of a Task Force to the Conference of Deputy Ministers of Health. Health and Welfare Canada, Ottawa. Ponder, R. C.; Dickson, J. H.; Harrington, P. R.; and Erwin, W. D. 1975. Results of Harrington instrumentation and fusion i n the adult i d i o p a t h i c s c o l i o s i s patient. J. Bone Joint Surg. 57A: 797-801. Ponseti, I. 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University of Toronto, September, 1979. (Mimeographed.) Wickers, Frank C.; Bunch, Wilton H.; and Barnett, P. M. 1977. Psychological factors i n f a i l u r e to wear the Milwaukee brace for treatment of i d i o p a t h i c s c o l i o s i s . C l i n . Orthop. 126: 62-66. Williams, J. Ivan, and Tice, Susan. 1980. A follow-up study of grade 6 students screened for s c o l i o s i s 1977-78. A report to the Scarborough Health Department. Health Care Research Unit. Uni v e r s i t y of Toronto, September, 1980. (Mimeographed.) Wilson, J . M. G., and Jungner, F. 1968. The p r i n c i p l e s and p r a c t i c e  of screening for disease. Public Health Papers No. 34, Geneva WHO. Wingate, Lydia. 1977. A model s c o l i o s i s screening program for the urban population of a large c i t y . Thesis for degree of Master of Science, Albany Medical College. 121 APPENDIX A Introductory Letter to Family APPENDIX B Interview Format Parent contact/interview Hello, I am Betty Wynne, a Public Health Nurse at Simon Fraser Health D i s t r i c t . I am c a l l i n g you at th i s time to ask for further information about what happened a f t e r your c h i l d p o ssible s c o l i o s i s . At Simon Fraser Health Unit we have conducted s c o l i o s i s screening since 1976 and f e e l i t i s timely to assess the re s u l t s of our program by determining what was the outcome of the r e f e r r a l s which were made. While no i n d i v i d u a l information w i l l be published I would appreciate some d e t a i l s about the follow-up which occurred a f t e r the r e f e r r a l f o r s c o l i o s i s . I recognize that you may not wish to answer these questions and that your p a r t i c i p a t i o n i s e n t i r e l y voluntary. You have the r i g h t to withdraw at any time. A f t e r your received the r e f e r r a l l e t t e r : 1) Did you take your c h i l d to your family physician? or was i d e n t i f i e d at school i n as having Yes No 2) Was an X-ray done? or Yes No What was the re s u l t ? 125 3) What was recommended for future follow-up? P o s s i b i l i t i e s are: a) R e f e r r a l to an orthopedic surgeon? or Yes No Name: b) Continued observation by family physician or Yes No c) No further follow-up required or Yes No d) Can't remember or Yes No 4) If r e f e r r a l to an orthopedic surgeon was made, what was h i s recom-mendation? a) Continued observation: at i n t e r v a l s of . b) X-rays or Yes No at i n t e r v a l s of . c) Bracing (type) , Exercises ; . d) Surgery . This has been most h e l p f u l . May I contact your physician and the orthopedic surgeon f or further information? or Yes No (If yes) I w i l l mail a consent form f or you to complete and return. Thank you very much. APPENDIX C Consent for Physician Contact 128 APPENDIX D Introductory L e t t e r to Physician APPENDIX E Questionnaire to Physician 132 I am continuing to observe Yes or No at i n t e r v a l s of ; This patient no longer requires observation Yes or No and can be categorized as: (i) minimal s c o l i o s i s (less than 10°) ( i i ) s t a b i l i z e d curve of degrees ( i i i ) n o n - s c o l i o t i c Yes or No (iv) or This c h i l d i s being followed by an orthopedic surgeon Name: * If treatment for s c o l i o s i s was i n s t i t u t e d : Bracing was applied (date) f o r (lengh of time) ( i f s t i l l i n brace please i n d i c a t e continuing) Surgery by Harrington Rod procedure was performed . Other Treatment: . Is further information obtainable by contacting another physician? Who i s : . We appreciate your assistance i n our program review. I f you would l i k e a summary of our evaluation please i n d i c a t e by a check here and a copy of our s c o l i o s i s program evaluation w i l l be mailed to you i n the f a l l . Betty Wynne Nursing Supervisor. APPENDIX F C e r t i f i c a t e of Approval 135 APPENDIX G Letter of Permission 

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