Translation, cross-cultural adaptation and validation of the Pain Catastrophizing Scale (PCS) into Bengali in patients with chronic non-malignant musculoskeletal pain

Aim To develop a culturally adapted and validated Bengali Pain Catastrophizing Scale (BePCS). Methods The English PCS was translated, adapted and back-translated into and from Bengali, pre-tested by 30 adult patients with chronic non-malignant musculoskeletal pain. The BePCS was administered twice with 14 days interval to 90 patients. Convergent validity was measured by comparing the BePCS score with scores of the domains physical functioning and mental health of the Bengali Short Form 36, through Spearman's correlation coefficient. Test-retest reliability was assessed by intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient and internal consistency by Cronbach's alpha. Content validity was assessed by index for content validity (ICV) and floor and ceiling effects. Results The BePCS was well accepted by the patients in the pre-test. The content validity was excellent, both item ICV and scale ICV were 1. Construct validity: the convergent validity was -0.424 for physical functioning and -0.413 for mental health, indicating a moderate negative correlation. Total BePCS score showed excellent internal consistency with a mean Cronbach's alpha = 0.92. Internal consistency for subscales rumination, magnification and helplessness, were Cronbach's alpha 0.903, 0.72 and 0.872 respectively. The test-retest reliability of total BePCS was 0.78 (P < .001) and for the subscales rumination 0.872 (P < .001), magnification 797 (P < .001) and helplessness 0.927 (P < .001), showing excellent test-retest reliability. Conclusions The interviewer-administered BePCS appears to be an acceptable, reliable and valid instrument for measuring health-related quality of life in Bengali speaking patients with chronic non-malignant musculoskeletal pain. Further evaluation in the general population and in different medical conditions should be done.