Inequalities In Brazils Illegal Drug-Related Acute Poisonings: An 18-Year Nationwide Analysis

BackgroundDespite rising drug use in Brazil, the proportion of severe acute drug-related poisonings has declined markedly. We investigated whether this improvement has been equitably distributed across ethnic and educational groups. MethodsEcological time-series study using the complete national series of moderate/severe exogenous intoxications notified to SINAN (Brazilian Notifiable Diseases Information System), 2007-2024 (n = 256,575). Severe outcome was defined as hospitalization with sequelae or death. Annual proportions of sociodemographic variables (sex, self-declared race/skin color, education, age) were entered into standardized multivariable linear regression, ridge regression, principal component analysis, and bootstrap (1,000 resamples). Counterfactual scenarios projected preventable severe cases through realistic reductions in low education. ResultsNotifications increased 15-fold while the severe case proportion fell 50% (11.4% to 5.7%; p < 0.001). Indigenous ethnicity was the only group independently associated with higher severity (standardized {beta} = +2.037, p = 0.038). Youth (15-19 years) conferred the strongest protection ({beta} = -3.315, p = 0.003), but this advantage was almost completely nullified among mixed-race (parda) youth (interaction {beta} = +9.65, p = 0.088). Low education showed strong protective association ({beta} = -1.601, p = 0.073). Counterfactual analysis estimated that 10-50% reductions in low education would avert 14-70 severe cases by 2030. ConclusionBrazil achieved one of the largest and fastest reductions in severe drug-related harm ever documented in a large population, driven by educational expansion and inclusion of marginalized groups into surveillance. Yet this success is profoundly stratified: indigenous individuals and mixed-race youth, the very populations whose inclusion fueled the rise in notifications, continue to bear a disproportionate burden of severe outcomes, revealing an inequality-constrained epidemiological transition.