Translation and Cross-cultural Adaptation of the Hip Disability and Osteoarthritis Score into Persian Language: Reassessment of Validity and Reliability

Background: This study aimed Persian translation and validation of the hip disability and osteoarthritis outcome score (HOOS) questionnaire. Methods: The study was carried out in two phases. First, we translated the HOOS according to acceptable guidelines. We assessed HOOS content convergent validity on 203 hip osteoarthritis patients using SF-36. Internal consistency was tested using Cronbach's alpha coefficient if each item removed and intraclass correlation coefficient (ICC) for the assessment of test-retest reproducibility. Results: Patients had mean (standard deviation) age of 39 (17). Test-retest ICC in whole was 0.95 (P = 0.014) showing excellent reliability. ICC was 0.92 for the "pain" subscale (P = 0.02), 0.81 for the "symptom" subscale (P = 0.002), 0.81 for the "function of daily living (FDL)" (P = 0.022), 0.88 for the "function of sports and recreational activities" (P = 0.006), but it was 0.62 (P = 0.1) for the "quality of life (QOL)." Cronbach's alpha was 0.92, 0.73, 0.97, 0.86, 0.80, and 0.80 for the pain, symptom, FDL, function of sports, QOL, and stiffness, respectively, showing good to excellent internal consistancy. Having SF-36 for the assessment of convergent validity, there was a strong correlation between total HOOS score and the physical component summary domain of SF-36 (r = 0.64, P = 0.0001), whereas the t correlation with the mental component summary domain was weak (r = 0.16, P = 0.04). Conclusions: The Persian version of the HOOS questionnaire is a valid (regarding physical not mental aspects) and reliable assessment tool in patients with hip osteoarthritis.