Translation and validation study of the Persian version of the Western Ontario Rotator Cuff Index

The translation, cultural adaptation and validation of the Persian version of the Western Ontario Rotator Cuff Index (WORC) were carried out in accordance with published guidelines. One hundred fifty consecutive patients with rotator cuff disorders completed the Persian WORC, the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure, the Short Form Health Survey (SF-36) and visual analog scale (VAS) to test convergent validity. Forty-five randomly selected patients completed the WORC 48 h later for the second time. High internal validity and discriminatory power of the WORC scales were found. Cronbach's alpha coefficient for the Persian WORC ranged from 0.85 to 0.92. The Persian WORC showed excellent test-retest reliability, with intraclass correlation coefficient ranging from 0.88 to 0.94 (P < 0.01). The Pearson's correlation coefficient between the Persian WORC total score and the DASH, the VAS and the SF-36 subscales was -0.76, -0.62 and 0.43 to 0.69, respectively (P < 0.001), indicating a good convergent validity. The results show that the Persian WORC is a reliable and valid instrument to measure health-related quality of life in Persian-speaking patients with rotator cuff disorders in Iran.