Explicit discrimination and health: development and psychometric properties of an assessment instrument

objective: to develop an instrument to assess discrimination effects on health outcomes and behaviors, capable of distinguishing harmful differential treatment effects from their interpretation as discriminatory events. methods: successive versions of an instrument were developed based on a systematic review of instruments assessing racial discrimination, focus groups and review by a panel comprising seven experts. the instrument was refined using cognitive interviews and pilot-testing. the final version of the instrument was administered to 424 undergraduate college students in the city of rio de janeiro, southeastern brazil, in 2010. structural dimensionality, two types of reliability and construct validity were analyzed. results: exploratory factor analysis corroborated the hypothesis of the instrument's unidimensionality, and seven experts verified its face and content validity. the internal consistency was 0.8, and test-retest reliability was higher than 0.5 for 14 out of 18 items. the overall score was higher among socially disadvantaged individuals and correlated with adverse health behaviors/conditions, particularly when differential treatments were attributed to discrimination. conclusions: these findings indicate the validity and reliability of the instrument developed. the proposed instrument enables the investigation of novel aspects of the relationship between discrimination and health.