Cross-cultural adaptation and validation of the Arabic version of the functional index for hand osteoarthritis

BACKGROUND: The Functional Index of Hand Osteoarthritis (FIHOA) is a clinically and methodologically validated score used to assess functional impact in patients with hand osteoarthritis (OA). The aim of the study was to translate the FIHOA into classical Arabic, and to validate the psychometric properties of the translated version. METHODS: The FIHOA was translated into Arabic (FIHOA-AR) according to cross-cultural adaptation guidelines. The FIHOA-AR was administrated to patients diagnosed with hand OA according to the criteria of the American College of Rheumatology (ACR). A 5-day test-retest reliability and internal consistency study was performed using the intra-class correlation coefficient (ICC) and the Cronbach’s alpha coefficient. External validity was measured by correlations between FIHOA-AR, hand pain visual analog scale (VAS) and the Health Assessment Questionnaire (HAQ). RESULTS: The sample consisted of 101 patients with hand OA. The obtained ICC > 0.9 and Cronbach’s alpha of 0.93 indicated excellent reliability and internal consistency respectively. The evaluation of external validity showed strong correlation with hand pain VAS (r = 0.88, p < 0.001), and strong correlation with HAQ score (r = 0.86, p < 0.001). CONCLUSION: The FIHOA-AR is a reliable and valid score to assess functional disability in Arabic- speaking patients with hand OA.