The Intersectional Discrimination Index - Revised: Refinement and further psychometric assessment

The Intersectional Discrimination Index (InDI) includes three measures of anticipated, day-to-day, and major discrimination for intercategorical intersectionality research. Previous studies found that the measures are unidimensional with high loadings, good test-retest reliability, predictive validity, and measurement invariance between Canadian and United States (US) samples. Gaps included the need for cognitive interviewing, reassessing stability of the measures' configural and metric structures in a diverse US sample and identifying ways to protect participant well-being. From 2021 through 2025 we conducted cognitive interviews, revised, and then psychometrically assessed the InDI-Revised (InDI-R) in English and Spanish among US adults, including a community-engaged sub-study with people living with HIV. We conducted 75 cognitive interviews and modified the measures to clarify that the InDI-Anticipated assesses future expectations, address ambiguity, add items about social distancing and mistreatment by family, and simplify response options. Next, we examined the internal validity of the English InDI-R in an online survey of Black, Latino/a/e, and White adults (n = 2,763, half sexual/gender minority). Confirmatory factor analyses indicated the InDI-R measures are unidimensional with high item loadings, consistent with the original InDI. Inter-item residual correlations indicated potential redundancies, which may be addressed by merging items in future studies. We also tested whether strengths-focused questions would protect respondent affect. Participants were happier and less upset when administered strengths-focused questions after the InDI-R. These results provide support for internal validity of the InDI-R measures and inclusion of strengths-focused items in discrimination studies.