Psychometric examination of the Persian version of Osteoarthritis Knee and Hip Quality of Life questionnaire.

Abstract

Osteoarthritis is a serious and prevalent health problem that creates considerable disability when it involves the knee or hip joints. The aim of the study was to adapt and validate the Osteoarthritis Knee and Hip Quality of Life (OAKHQOL) questionnaire for use in a Persian-speaking population. A total of 434 patients were recruited. The forward-backward translation process was used to develop the Persian version. Participants were asked to complete the Short Form 12 Health Survey, EuroQoL, visual analog scale for pain and the OAKHQOL questionnaire. Reliability was assessed using Cronbach's alpha and the test-retest method. The structure of the questionnaire was evaluated by exploratory factor analysis. The OAKHQOL was correlated with related measures to establish construct validity. Convergent and discriminant validity were examined with demographic and clinical variables. Comparisons were performed between patients with different severity grades of osteoarthritis. The mean age of participants was 61.9 (SD 12.1) and the majority were female (91.2%). Principal component analysis demonstrated a five-factor solution that explained 58.4% of the variance. Cronbach's alpha coefficients ranged between 0.74 and 0.89 for all domains of the questionnaire with the exception of the social activities domain. The kappa for test-retest reliability was 0.85. The OAKHQOL demonstrated good discriminative and convergent validity. Construct validity was established by determining significant relationships between related measures. The results of known-groups validity indicated different scores on most domains (P<0.001) across different levels of disease severity. The questionnaire may be used as a valid and reliable measure for assessing quality of life among Iranian patients with lower limb osteoarthritis.