Cardiovascular mortality among the Black population in Brazil

why do regional division and population size not explain state-level variation?

Abstract

Objective: this study aimed to describe the distribution of the proportion of black cardiovascular mortality (NMP) in Brazilian states and to test whether geopolitical factors explain its heterogeneity. Methods: a descriptive ecological study was conducted with data from the Mortality Information System (SIM/DATASUS) between 1996 and 2024. The main outcome was the PMN, defined as the ratio between cardiovascular deaths of black and brown individuals and the total number of cardiovascular deaths in each state, without standardisation for state racial population composition. The Shapiro-Wilk test was applied for normality, the Kruskal-Wallis test for regional comparisons, and the Spearman correlation test was applied to evaluate the association with the state population size. An exploratory OLS regression model was adjusted using region and size as predictors. Results: of the 9,291,685 cardiovascular deaths recorded, 743,045 (8.0%) occurred in the black population. The average PMN among the states was 7.47%, with a 5.8-fold variation between the highest index (Rio de Janeiro, 15.0%) and the lowest (Santa Catarina, 2.6%). The analysis showed that regional differences were not statistically significant (p = 0.147), and the state population size did not correlate with the PMN (p = 0.758). The OLS model was also not significant (adjusted R² = 0.077; p = 0.253), indicating that traditional geopolitical variables do not explain the observed variance. Conclusions: the proportional participation of black individuals in cardiovascular mortality shows high inter-state and intra-regional heterogeneity in Brazil. The fact that geographic region and population size do not explain this variation suggests that the elevated proportional representation of Black individuals in cardiovascular mortality is driven by more complex structural factors — consistent with hypotheses involving local demographic composition, differential access to care, and structural racism. These findings reinforce the need for equity policies that consider specific racial indicators in addition to the absolute volume of deaths.