Psychometric assessment of the EMIC Stigma Scale for Brazilians affected by leprosy

Background The Stigma Scale of the Explanatory Model Interview Catalogue (EMIC-SS) is a useful option to investigate leprosy-related stigma, but its psychometric qualities are unknown in Brazil. This study investigated the factor structure, the convergent and known-groups validity, and the reliability of the EMIC-SS for Brazilians affected by leprosy. Methodology The Brazilian Portuguese version of the EMIC-SS was validated in 180 persons affected by leprosy at a Reference Center in Rio de Janeiro. Confirmatory factorial analysis (CFA) and Cronbach alpha were used to assess the EMIC-SS internal consistency. The Construct validity was tested using Spearman Correlation, Kruskal-Wallis, and Mann-Whitney tests comparing with the Participation Scale, Rosenberg Self-esteem Scale, Beck Depression Inventory, and a Sociodemographic Questionnaire. Test-retest reliability was evaluated with intra-class correlation (ICC). Main findings CFA confirmed the one- and two-dimensional models of the scale after retaining 12 of the 15 EMIC-SS items. The 12—item EMIC-SS was consistent (α = 0.78) and reproducible (ICC = 0.751, 95% Confidence Interval = 0.657–0.822, p < 0.0001). A significant correlation was observed between the EMIC-SS and the other scales confirming convergent validity. The EMIC-SS and its factors were able to differentiate several hypothesized groups (age, change of occupation, monthly family income, communicating others about the disease, and perception of difficulty to follow treatment) confirming the scale known-groups validity, both in its one and two-dimensional models. Conclusions/Significance Our study found support for the construct validity and reliability of the EMIC-SS as a measure of stigma experienced by people affected by leprosy in Brazil. However, future studies are necessary in other samples and populations with stigmatizing conditions to determine the optimal factor structure and to strengthen the indications of the validated scale.