Factor structure of the Bengali version of atopic dermatitis burden scale for adults: A cross-sectional study

Abstract

Background: Atopic dermatitis (AD) is associated with increased burden and reduced health-related quality of life (HRQoL); however, there is no available Bengali questionnaire assessing the same. Purpose: We aimed to develop the Bengali version of the questionnaire and examine its cross-cultural adaptability considering linguistic equivalence. Methods: A multicentric, mixed methods, cross-sectional study was conducted through the consecutive sampling at the outpatients of three homeopathy hospitals in West Bengal. The Bengali version of the questionnaire was produced by standardized forward-backward translations. Psychometric analysis was run to examine its factor structure, validity, and reliability. Reliability was examined using internal consistency (n = 230). Construct validity was examined by the exploratory factor analysis (EFA; n = 115) using the principal component analysis (PCA; varimax rotation). Subsequently, confirmatory factor analysis (CFA; n = 115) was performed to verify the model fit. Results: The internal consistency (Cronbach's α =0.876 (95% confidence interval 0.851–0.898)), test-retest reliability and concurrent validity – all were within the acceptable limits. The Kaiser-Meyer-Olkin (KMO = 0.793) and Bartlett's test of sphericity (Chi-square: 1038.981 at 153° of freedom, P < 0.001) both suggested adequacy of the sample. In factor analysis using varimax, all the items loaded above the prespecified value of 0.4 and identified five components, explaining 68.3% of the variation. The goodness-of-fit of the 5-components model in CFA was also acceptable (comparative fit index = 0.858, Tucker Lewis index = 0.823, root mean square error of approximation = 0.102, and standardized root mean square residual = 0.188). Conclusion: The Bengali version of the questionnaire consisting of 18 items and framed within five components appeared to be a valid and reliable instrument measuring disease burden and HRQoL in adults suffering from AD.