Responsiveness of the Short-Form 36 and Oswestry Disability Questionnaire in Chronic Nonspecific Low Back and Lower Limb Pain Treated With Customized Foot Orthotics

Abstract

Purpose This study reports the responsiveness of the Short-Form 36 (SF-36) and Oswestry Disability Questionnaire (ODQ) to treatment with customized foot orthotics. Methods Thirty consecutive patients presenting to a primary care clinic with chronic (>3 months), nonspecific, low back pain and/or soft tissue lower limb disorders completed the SF-36 and ODQ before and 6 weeks after prescription of customized foot orthotics. Locations of any pain in the lower half of the body (including the low back), age, sex, and duration of the most chronic pain were recorded. Responsiveness statistics of the ODQ and SF-36 physical and mental summary scores were calculated, as was correlation among these scores and the self-reported pain improvement scores. Results All subjects completed the baseline and 6-week questionnaires. The mean age of the sample was 53.9 ± 12.9 years, with 57% men and 43% women. The mean duration of the most chronic pain symptom was 14 ± 14 months (range, 3-60 months). The mean ODQ score at baseline was 42.8% ± 14. 8% and at 6 weeks was 16.6% ± 5.0%. The physical component score of the SF-36 was 39.8 ± 5.0 at baseline and at 6 weeks was 47.3 ± 3.8. The mental component score of the SF-36 at baseline was 45.7 ± 6.1 and at 6 weeks was 47.9 ± 5.0. The responsiveness of the ODQ was calculated to be 9.40, the responsiveness being 1.77 for the physical component score of the SF-36 and 0.24 for the mental component score of the SF-36. Conclusions In this cohort, the ODQ and the physical component of the SF-36 appear to be responsive to treatment effects, with the ODQ having the highest responsiveness. The ODQ may be a useful outcome measure in trials of the effectiveness of customized foot orthotics in patients with nonspecific, chronic low back and/or soft tissue lower limb pain.