Objectives: To compare responsiveness and minimal clinically important change (MCIC) for the disease-specific Western Ontario Rotator Cuff index (WORC) and the two region-specific questionnaires Shoulder Pain and Disability Index (SPADI) and Oxford Shoulder Scale (OSS) in patients with rotator cuff disease receiving corticosteroid injection therapy.
Study design and setting: One hundred twenty-one patients with rotator cuff disease. Western Ontario Rotator Cuff index, SPADI, and OSS were administered before treatment and at 2 and 6 weeks after corticosteroid injection. Responsiveness was compared between questionnaires using the standardized response mean (SRM), area under the receiver operating characteristic curve, and reliable change proportion (RCP) statistics. Minimal clinically important change estimates were reported.
Results: The differences between questionnaires were small and not consistent across the different responsiveness indices. Shoulder Pain and Disability Index was significantly more responsive than OSS measured by SRM and RCP at 2 and 6 weeks. Western Ontario Rotator Cuff index was significantly more responsive than OSS in RCP and area under receiver operating characteristic curve at 6 weeks. Shoulder Pain and Disability Index was significantly more responsive than WORC measured by RCP at 2 weeks. Minimal clinically important change was estimated to 5, 275, and 20 points for OSS, WORC, and SPADI, respectively.
Conclusions: All questionnaires are suitable for measuring change in patients with rotator cuff disease. Disease-specific WORC index is not more responsive than the region-specific SPADI and OSS in rotator cuff disease.