Social disorganization and homicide mortality rate trajectories in Brazil between 1991 and 2010

•Spatial and temporal heterogeneity in homicide trajectories among Brazilian cities was found.•A small proportion cities (16.52%) accounted for 73.4% of all homicides within the study period.•Cities with high social disorganization are more likely to experience an increasing trajectory.

Since the 1990s, researchers have noted declining trends in crime and violence, particularly homicide, in Western countries. Studies have explored national and sub-national trends using latent trajectory analysis techniques and identified several factors associated with declining and/or increasing trajectories. Social disorganization (SD) has been consistently linked to increases in homicide rates over time, explaining at least some of the spatial and temporal heterogeneity of homicide. Similar studies have not yet been carried out in Latin America's cities. In this paper we use Group Based Trajectory models to study homicide mortality rate [HMR] trajectories in Brazilian municipalities between 1991 and 2010. Then, through binary and multinomial logistic regression we investigated the association between SD in 1991, and the likelihood of an increasing HMR trajectory. We carried out an ecological time series study using all Brazilian municipalities in the period between 1991 and 2010 (n = 4491). Data on homicide deaths were collected from the Mortality Information System of the Ministry of Health and standardized by age to calculate HMR per 100,000 population. Socioeconomic and demographic data for 1991 were used to compose the composite measure of SD. Our results highlight the spatial and temporal heterogeneity of homicide mortality in Brazilian municipalities. While national trends are steadily increasing, disaggregating municipal trajectories shows that this is driven by a small proportion of municipalities in the country. We found that SD is associated with an ascending homicide trajectory. This result generally supports the notion that poor social structural conditions can create 'space' for criminal behavior and groups and, consequently, violent death.