RESUMEN
BACKGROUND: This study was focused on translation and cultural adaptation of the English Lequesne Algofunctional index (LAI) into Bengali for patients with primary knee osteoarthritis (OA) and testing reliability and validity of the Bengali version of the LAI. METHODS: This study was carried out in the Department of Rheumatology, BSM Medical University, Dhaka, Bangladesh. Using the forward-backward method the English LAI was translated into Bengali including cultural adaptation. For pretesting, A sample of 40 patients with primary knee osteoarthritis were screened using the Bengali version of LAI. Following the pretest, 130 consecutive patients with symptomatic knee OA completed the interviewer administered Bengali LAI, the validated Bengali version of SF-36, Visual Analogue Scale for Pain, Distance Walked and Activities of Daily Living. For the retest 60 randomly selected patients from the cohort were administered the Bengali LAI 7 days later. An item by item analysis was performed. Internal consistency was assessed by Cronbach's alpha, test-retest reliability by intraclass correlation coefficient (ICC) and Kappa coefficient, construct validity was measured using the Spearman rank correlation coefficient. RESULTS: It took 3.25 ± 0.71 min to complete the Bengali LAI and the mean score was 9.23 ± 4.58. For the Bengali LAI Cronbach's alpha score was 0.88, test-retest reliability assessed by ICC was 0.97. For construct validity, excellent convergent validity was achieved (ρ = 0.93) but the divergent validity was moderate (ρ = 0.43). CONCLUSIONS: The Bengali LAI showed excellent convergent validity, internal consistency and test-retest reliability, only the divergent validity was moderate. So, the Bengali LAI can be applied as a HRQoL assessment tool for primary knee OA patients.