Measuring mental well-being in Sri Lanka: validation of the Warwick Edinburgh Mental Well-being Scale (WEMWBS) in a Sinhala speaking community

Background Well-being is an important aspect of people's lives and can be considered as an index of social progress. The Warwick Edinburgh Mental Well-being scale (WEMWBS) was developed to capture subjective mental well-being. It is a widely tested measure of mental well-being at the population level and has 14 items and a short-form with 7 items. This study was carried out to culturally validate and adapt the WEMWBS among a Sinhala speaking population in Sri Lanka. Methods A forward and backward translation of the scale into Sinhala was done followed by a cognitive interview. The translated and culturally adapted scale and other mental health scales were administered to a sample of 294 persons between the ages of 17-73 using a paper-based version (n = 210) and an online survey (n = 84). Internal consistency reliability and test-retest reliability were tested. Construct validity, and convergent and discriminant validity were assessed using the total sample. Results The translated questionnaire had good face and content validity. Internal consistency reliability was 0.91 and 0.84 for the 14-item and 7-item scales, respectively. Test-retest reliability over two weeks was satisfactory (Spearman r = 0.72 p < 0.001). Confirmatory factor analysis supported a one factor model. Convergent validity was assessed using WHO-5 well-being index (Spearman r = 0.67, p < 0.001), Patient Health Questionnaire (PHQ-9) (Spearman r = (-0.45), p < 0.001) and Kessler psychological distress scale (K10) (Spearman r = (-0.55), p < 0.001). Conclusions The translated and culturally adapted Sinhala version of the WEMWBS has acceptable psychometric properties to assess mental well-being at the population level among the Sinhala speaking population in Sri Lanka.