Comparison of the responsiveness of the Harris Hip Score with generic measures for hip function in osteoarthritis of the hip

Objective: To compare responsiveness of the Harris Hip Score with generic measures (that is, the Short Form-36 (SF-36), and a test of walking speed and pain during walking) in patients with osteoarthritis (OA) of the hip. Method: The first 75 cases within the population of a randomised clinical trial on manual therapy and exercise therapy were selected for secondary analysis. Experienced (self reported) recovery by the patients after treatment (five weeks) was used as an external criterion for clinically relevant improvement. Responsiveness was evaluated by comparing responsiveness ratios and receiver operating characteristic curves. Results: The responsiveness ratio for the Harris Hip Score was high (1.70) compared with walking speed (0.45), pain during walking (0.66), and the subscales of the SF-36 -"bodily pain" (0.42) and "physical functioning" (0.36). The area under the curve also was highest for the Harris Hip Score (0.92) compared with walking speed (0.71), pain during walking (0.73), and the SF-36 subscales bodily pain and physical functioning (both 0.66). Conclusion: The Harris Hip Score is more responsive than the test of walking speed, pain, and subscales for function of the SF-36 in patients with OA of the hip. The Harris Hip Score seems to be a suitable instrument to evaluate change in hip function in patients with OA of the hip.