Bangla WHO-5 well-being Index among persons with disabilities: a psychometric validation applying classical test theory and Rasch Model

Persons with disabilities face numerous barriers that affect their well-being, yet no validated Bangla tool exists to assess subjective well-being in this population. This study validated the Bangla WHO-5 Well-being Index among 518 adults with disabilities from rural and urban areas of Bangladesh. Reliability and validity were examined using Classical Test Theory and Rasch analysis. The scale demonstrated a unidimensional structure with good model fit (CFI = 0.98, TLI = 0.96, RMSEA = 0.06). Internal consistency was acceptable (α = 0.63), and test–retest reliability was excellent (ICC = 0.87). Convergent and divergent validity were supported. Rasch analysis showed acceptable item fit and strong item and person separation reliability. Findings suggest that the Bangla WHO-5 is a valid and reliable measure of subjective well-being among persons with disabilities.