UBC Theses and Dissertations
Medically incongruent back pain presentation : an indication of physical restriction, suffering, and ineffective coping with pain Reesor, Kenneth Alan
Chronic low back pain (CLBP) patients who display or report pain that is deemed incongruent and anatomically non-conforming relative to known organic impairment and expected symptomatology have been found to have a poorer outcome to medical treatment and rehabilitation, and to use health care resources excessively. The present investigation sought to contrast CLBP patients who displayed either multiple non-organic physical signs, multiple inappropriate symptoms, and/or anatomically incongruent pain drawings with a control CLBP patient sample in which these criteria were absent. A total of 80 CLBP patients, 40 with 'medically incongruent' pain and 40 'control' pain patients, completed as part of their assessment at a back pain clinic, a psychometric battery, a physical examination, a videotaped sequence of motor movements and positions, and an assessment with an experimental pressure pain induction task. Videotaped pain behavior observations and transcribed reports of cognitions during the pain induction were coded independently of pain group status. Dependent measures and other patient variables were subjected to 2 X 2 (pain group by sex) MANOVAs and appropriate univariate analyses. While there were no interaction effects in these analyses, and only minimal effects for sex, there were a number of significant effects for pain group. No differences emerged between pain groups on demographic, pain history, financial disincentives, or medication consumption, but self report and physical examination measures of physical limitation were higher in the incongruent pain group. The incongruent pain group also received higher scores on measures of pain intensity and depression, received higher global judgment ratings of pain, displayed more ambulatory/postural pain behavior, and reported more dysfunctional cognitions during pain experiences than the control group. When physical impairment/limitation was introduced as a covariate in MANCOVAs on the dependent variables, incongruent pain patients emerged as significantly different from control pain patients on the cognitive variables, but behavioral and self-report differences failed to emerge as significant. A discriminant analysis revealed that sense of control during the experimental task was the most important discriminator between the groups. These results highlight the role of cognition in CLBP patients who present with medically incongruent pain signs and support the idea that physically based interventions may fail with these patients because dysfunctional cognitive mediation of pain may not be altered. These results also suggest that these patients may be better conceptualized as being ineffective and overwhelmed in their attempts to cope with their chronic pain condition.
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