RELATIONSHIP OF THE PAIN DISABILITY INDEX (PDI) AND THE OSWESTRY DISABILITY QUESTIONNAIRE (ODQ) WITH 3 DYNAMIC PHYSICAL TESTS IN A GROUP OFPATIENTS WITH CHRONIC LOW-BACK AND LEG PAIN

Objective: To determine the relationship between overall disability in daily activities, assessed with the Pain Disability Index (PDI) and t he Oswestry Disability Questionnaire (ODQ), and impaired performance o n three physical tests in patients with chronic low-back pain. Design and Subjects: The PDI and ODQ were administered in a cross-sectional s tudy, before beginning a back rehabilitation program, to 45 patients w ith low-back pain of greater-than-or-equal-to 3 months' duration, with or without radiation to the legs. All patients also performed repetit ive sit-up, arch-up, and squatting tests. Setting: Tertiary care cente r. Results: Modestly significant (p < 0.05) or significant (p < 0.01) inverse correlations (Pearson's r = 0.30-0.41) were noted between the PDI and the ODQ and all three physical performance tests. When normati ve data were used, the correlation (Spearman's r(s) = 0.45) between PD I and the squatting test remained significant (p < 0.01), whereas it w as modestly significant (r(s) = -0.33, p < 0.05) between the ODQ and s quatting test and between the PDI and arch-up test (r(s) = -0.35, p < 0.05). Compared with patients presently working, those on sick leave h ad significantly higher scores on the PDI and ODQ (Wilcoxon's two-samp le test: p < 0.001) and also significantly worse performance on all ph ysical tests (p < 0.001). Conclusions: The PDI and ODQ, as measures of self-perceived disability, and impaired performance on repetitive squ atting, arch-up, and sit-up tests, as measures of physical capability, show some overlap in low-back-pain patients. Both types of disability measures are clearly influenced by the patient's work status.