Urban Segregation in Brazil: The Spatial Dimension of Health Inequalities

Introduction: Segregation means enforced separation of disadvantaged social groups. The triple burden of being poor, in a poor neighborhood which is spatially segregated,  favours the reproduction of poverty and affects the health of segregated groups as well the health of the population. There are a number of dimensions of segregation which can be measured through indices of spatial clustering, isolation and exposure to other social groups which may produce a clearer map of the social determinants of health. Objectives: To analyze the association between socioeconomic urban segregation and population health. Methods: Cross-sectional and ecological study. Secondary data for ten Brazilian Capitals was obtained from the census and from the mortality information system. The health outcome variable, aggregated to the district level (n=860), was cerebrovascular mortality. There were two levels of explanatory variables: the district level that included scores of spatial and local socio-economic segregation (exposure, isolation and clustering indexes) and income and the city level which included data on development and inequalities. Mapping techniques, multilevel regression analysis, testing for spatial autocorrelation and spatial regression were used to check the association between segregation indices and health outcome. Results: In most cities, districts with the poorest health were also districts with the highest segregation of the poorest groups in terms of their isolation, lack of spatial exposure to other social groups and spatial clustering. In contrast, districts with the best health were ones where the rich were isolated and lacked exposure to the poor. Conclusions: Within Brazilian Capitals, the disadvantaged social groups are spatially segregated. The data suggests that segregation is bad of the health of poor districts and good for the health of the rich districts. This process of segregation leading to divergent health outcomes depending on the socioeconomic profile of communities supports the triple burden hypothesis and intensifies health inequalities.