Background Spatial and socioeconomic inequalities in health are well-documented across the world, with poorer people, areas and regions experiencing poorer health and higher mortality risks than richer people, areas and regions. Furthermore, greater income inequality has also been linked to higher mortality rates. However, there has been less work on the spatial dimension of such socioeconomic inequalities in relation to inequalities in health. The UN-Habitat 2010–11 report on the state of the world’s cities identified the spatial isolation of poor people in cities (the “spatial poverty trap”) as one of the major challenges in developing countries. As people and cities in the developing world get richer, the worry is that the spatial socioeconomic segregation of poor people increases, which in turn may increase their risks of mortality and poor health.
Methods Data from 15 major Brazilian cities were analysed, with spatial measures of socioeconomic segregation (“isolation of the poor”) estimated for Brazilian districts within cities. The association of the spatial isolation of the poor with district level mortality rates was examined using multiple membership multilevel Poisson regression models to take account of the multilevel (districts within cities) and spatial nature of the data.
Results Increasing spatial isolation of the poor tends to be associated with higher mortality rates, with an interaction between income and spatial isolation. There is not much difference in mortality rates among the poorest districts in terms of spatial isolation. However in the richest districts, districts where the poor are spatially isolated have the highest mortality rates, whereas districts where the poor are not isolated have the lowest mortality rates.
Conclusion As cities in the developing world get richer, there is a risk that this leads to increasing spatial socioeconomic segregation of the poor within those cities. The results from this study suggests that the spatial dimension of poverty within cities may be just as important to health as poverty levels.