[Ethnicity/race in the Pró-Saúde Study: comparative results of two methods of self-classification in Rio de Janeiro, Brazil].

Variations in classification systems related to color/race and the contextual dependence of their utilization are two challenges for researchers conducting health studies within an ethnic/racial framework. A comparison was made between the results obtained by two distinct approaches to racial self-classification -- a closed question (using categories from the IBGE, or National Census Bureau) and an open-ended question -- in a cohort study of employees at a university in Rio de Janeiro. According to the closed question, 54.0% of the 3,717 respondents classified themselves as white, 30.0% as brown (or mixed-race), and 16.0% as black. According to answers to the open-ended question, the proportions were 53.0%, 25.0%, and 22.0%, respectively, when the terms "moreno", "mestiço", and "mulato" were grouped under the "brown" category. Despite the high level of agreement (kappa = 0.80; 95%CI: 0.78-0.82), a sizeable numbers of black and brown respondents (open-ended question) chose "whitening" categories available in the list supplied by the IBGE. The use of ethnic/racial categories in health studies can both reveal information on health inequalities in Brazil and also contribute to the formulation of public health policies adequately informed by the specificities of Brazilian society.