Ambient temperature and homicide mortality in 307 Latin American cities: A case time series design

Homicide is a leading cause of death in many countries, and growing evidence suggests that short-term variations in ambient temperature, especially high temperatures, might be associated with higher risk of homicide. Latin America is the most violent region in the world, yet knowledge about the linkages between ambient temperature and homicide mortality in the region remains limited. We conducted a case time series design using conditional quasi-Poisson and distributed lag non-linear models to estimate short-term associations (0-7 lag days) between daily mean temperature and homicide deaths in 307 cities in seven Latin American countries from 2000 to 2019. During this period 1,193,110 homicide deaths were reported. Our findings showed that high temperatures were associated with an increased risk of homicide mortality. The excess fraction of homicide deaths attributable to extreme heat (≥95th percentile of temperature) was 0.61% (95% CI: 0.51, 0.72%). The stratification analysis indicated minimal heterogeneity across sex, and age group categories. There was no evidence that associations were modified by city-level educational attainment or city Gross Domestic Product per capita. Our study highlights the association between high temperatures and increased homicide mortality risk. This represents a pressing concern given global environmental temperature trend and the already high burden of homicide mortality in Latin America. More attention at the local, regional and continental scales is needed to incorporate environmental concerns into homicide prevention strategies.