Prevalence, Perpetrators, and Patterns of Violence in Pelotas, Brazil: A Cross-Cohort Analysis Over Four Decades.

Interpersonal violence is a major public health concern in Brazil, yet its epidemiology remains poorly understood. In this study, we examined four decades of violence using the municipality of Pelotas, Brazil, which has uniquely rich administrative and cohort data. We analysed trends in officially recorded and self-reported violence from 1980 to 2024 using administrative data and three population-based birth cohorts (1982, 1993, and 2004). Self-reported violence perpetration was measured using harmonised questionnaires at comparable ages and recall periods. LOESS regression smoothed long-term trends and chi-squared tests assessed changes in perpetrator profiles. Violence increased sharply from the 1980s, peaked in 2017, and declined thereafter, with consistent patterns observed across mortality, hospitalisation, and police records. Cohort data mirrored these trends: 12.6%-15.7% of individuals reported perpetrating violence, with the highest prevalence in the 1993 cohort. Individuals born in 2004 had 21% lower odds of perpetration compared with those born in 1993 (Odds ratio = 0.79; 95% confidence interval [0.69, 0.90]). Physical assault drove these trends, while weapon carriage increased in more recent cohorts. Socio-demographic patterns were largely stable over time; however, female perpetration increased across cohorts, particularly for physical assault and weapon carriage. These findings indicate that the rise in violence, and the more recent decline, in Brazil was universal and affected both lethal and non-lethal forms of violence. Additional research is needed to better understand the recent decline in violence and explore why violence perpetration might be becoming more prevalent among women. Understanding the evolving epidemiology of violence in Brazil is critical for designing responsive violence prevention strategies.