Income inequalities and stroke mortality trends in Sao Paulo, Brazil, 1996-2011

Background: It is not clear the relationship between stroke mortality trends and socioeconomic inequalities in low- and middle-income countries.

Aims: We compared differences of trends in stroke mortality by socioeconomic status in the city of Sao Paulo, Brazil.

Methods: We analyzed the intra-urban distribution of stroke death rates from 1996 to 2011 for persons aged 35-74 years old according to income using joinpoint regression.

Results: We confirmed 77 848 stroke deaths in the period, 51·4% of them among persons aged 35-74 years old. For all areas, there was parallelism between genders, and the average annual percent changes combined was -5·2 (-5·7 to -4·6) from 1996 to 2005 and -3·0 (-4·3 to -1·7) from 2005 to 2011. The full period average annual percent changes of age-adjusted rates between persons living in the high- and low-income area were, respectively, -5·4 and -4·2 (P = 0·002) for men and -5·9 vs. -4·9 (P = 0·017) for women. Differences in the risk of stroke between the high- and low-income areas increased more than twofold in the period in both genders.

Conclusions: The risk of stroke death is decreasing in all regions, but the faster decline in mortality rates in the wealthiest area contributes to further greater inequalities.