Georeferencing deaths from stroke in São Paulo: an intra-city stroke belt?

Abstract

The role of socioeconomic status in the worldwide stroke burden has been studied with various methods using vital statistics and research-generated data. The objective of our study was to describe the stroke mortality rates and the stroke mortality distribution, and to evaluate the association between stroke mortality rates and geographical distribution with the human development index in São Paulo, Brazil. This ecological study evaluated a historical series of stroke mortality in São Paulo, Brazil, from 2004 to 2010. Standard stroke mortality rate per 100 000 inhabitants at each year, the address of residence assumed as the place of living, and the human development index applied as a social indicator were used in order to evaluate if stroke mortality correlated with socioeconomic status. The mean standardized stroke mortality in São Paulo decreased from 66 to 46·7 per 100 000 inhabitants from 2004 to 2010. Stroke mortality differed according to human development index strata with an almost three times higher stroke mortality in the lowest when compared with the highest human development index stratum. Visual inspection of the map of the districts with high stroke mortality disclosed regional clusters with high mortality in the east, northwest, and south regions, a finding suggestive of the presence of a stroke belt inside the city of São Paulo. In conclusion, between 2004 and 2010, stroke mortality rates decreased by 28·5% in São Paulo. A geographical pattern in stroke mortality could be observed, with considerable differences according the human development index level of the place of living.