LOW-BACK-PAIN OUTCOME MEASUREMENT ASSESSMENT IN CHIROPRACTIC TEACHING-CLINICS - RESPONSIVENESS AND APPLICABILITY OF 2 FUNCTIONAL DISABILITYQUESTIONNAIRES

Objective: The major aims were to evaluate responsiveness and clinical /research applicability of the Revised Oswestry Disability Questionnai re (ODQ) and the Dallas Pain Questionnaire (DPQ). Construct and conten t validity were assessed. Patient characteristics and outcomes were al so documented. Design: Longitudinal observational study. Setting: Coll ege outpatient clinics. Participants: Six hundred sixty-three consecut ive new patients accepted for treatment of low back pain (LBP) at the clinics over a 1-yr period, age 18 or older. Interventions: Treatment of low back pain by senior interns under the supervision of staff clin icians. Main Outcome Measures: ODQ and DPQ administered at baseline, 2 wk, 1 month, and monthly up to 6 months. Responsive ness: mean standa rdized change score (Delta' = mu(dif)/sigma(dif)), relative efficiency ([RE = Delta'(ODQ)/Delta(DPQ)](2)), and improvement rates (IR). Appli cability: instrument completion rates. Construct validity: correlation with VAS for pain intensity. Results: ODQ responsiveness was generall y consistent over time (Delta' =.70-.83) and negligibly better than th e DPQ activities of daily living scale (RE = 1.00-1.35); most patients self-reporting improvement showed positive outcomes (IR = 97%). For l arge samples (n > 100): Delta' =.47-.63 and IR = 81% for the DPQ work/ leisure scale; Delta' =.17-.40 and IR = 54% for the DPQ anxiety/depres sion and social dimensions. Completion rates: 65%-78% of all instrumen ts; 81%-100% of individual scales. Construct validity: r = .44-.68 for the ODQ, DPQ activities of daily living, and DPQ work/leisure scales; r = .20-.40 for the anxiety/depression scale. Conclusions: The ODQ an d the activities of daily living and work/leisure scales from the DPQ appear appropriate for monitoring LBP patients returning for care to c hiropractic teaching clinics. The social and anxiety/depression dimens ions of the DPQ do not appear to be responsive in this population. The latter scale may be unsuitable on the grounds of misinterpretations.