Psychometric Properties of Full and Shortened Persian-version of Western Ontario Rotator Cuff Index Questionnaires in Persian-speaking Patients with Shoulder Pain

Background: This study aimed to translate the shortened Western Ontario Rotator Cuff (Short-WORC) questionnaire into Persian and determine the psychometric features of WORC and Persian-Short-WORC in patients with shoulder pain.Methods: A total of 130 patients completed Persian-WORC and -Short-WORC, Shoulder Pain And Disability Index (SPADI), shortened Disability of Arm, Shoulder, and Hand (Quick-DASH), WORC, as well as Short-Form health survey (SF-36), in the evaluation and re-evaluation sessions with an interval of 5-7 days to assess reliability and validity. To determine responsiveness, all patients completed questionnaires and a global rating of change scale before and after the 4-week physiotherapy. Intra-class correlation coefficient (ICC) was used for assessing reliability, two-tailed Pearson (r) forvalidity, as well as longitudinal validity, and receiver operating characteristics (ROC) curve analysis for responsiveness.Results: The ICC was 0.95 (confidence interval: 0.93-0.96) for Short-WORC. A strong correlation was found between Short-WORC, SPADI (r=-0.82), Quick-DASH (r=-0.79), WORC (r=0.92), SF-36 physical (r=0.76), and SF-36 mental (r=0.71). Floor and ceiling effects were not detected. The responsiveness of Short-WORC and WORC was proven with an area under the curve of 0.90, and their minimal important change was 28.56 and 26.28 points, respectively.Conclusion: The Persian version of WORC has good psychometric properties to measure disability and health-related quality of life in patients with shoulder pain. Level of evidence: IV