Measurement properties of the Western Ontario rotator cuff outcome measure: a preliminary report.

The purpose of this prospective repeated-measures outcomes study was to investigate the construct validity and sensitivity to change of a newly developed outcome measure, the Western Ontario Rotator Cuff Index (WORC) in a population of patients seen at a tertiary shoulder center. A total of 154 subjects (66 women and 88 men; mean age, 48 years [SD, 14.80 years]) agreed to participate in the study. Of these, 50 patients (16 women and 34 men; mean age, 50 years [SD, 14.36 years]) met the criteria for surgery. The Pearson correlation coefficients between the initial scores and the change scores at 6 months postoperatively of the WORC, Constant-Murley shoulder form, and American Shoulder and Elbow Surgeons standardized shoulder assessment form were high (P < .01). The WORC was sensitive to detect change: F = 28.041 and P < .000 at 3 months and F = 66.927 and P < .000 at 6 months postoperatively. The results of this study support the validity of the WORC for use in patients with rotator cuff pathology.