Examining psychometric properties of the Sinhala version of the ‘Opening Minds Scale for Health Care Providers’ to measure stigma towards mental illness using confirmatory factor analysis

Confirmatory Factor Analysis for the first-order three-factor model of OMS-HC15 showed acceptable model fit indices (χ2/df = 2.11, CFI = 0.943, TLI = 0.932, RMSEA = 0.082, SRMR = 0.086), but one item demonstrated inadequate factor loading (< 0.3). Considering the poor factor loading and concerns raised on the relevance of this item by previous researchers, this item was removed. However, as removing this item resulted in a slightly worse model fit, modification indices were examined, and constraints on three error covariances were relaxed. This led to a good model fit for the 14-item scale (CFI = 0.962, TLI = 0.951, χ2/df = 1.88, RMSEA = 0.074, SRMR = 0.079). Higher-order, bifactor, and unidimensional models were not supported. The 15-item scale showed acceptable reliability (ω = 0.80; α = 0.69), which improved after removing Item 11 (ω = 0.81; α = 0.70). Subscale reliabilities were lower (Social Distance: ω = 0.70, α = 0.69; Disclosure/Help-Seeking: ω = 0.62, α = 0.61; Attitudes: ω = 0.58, α = 0.55).