Forensic patterns and epidemiology of intimate partner violence in Brazil: A nationwide cross-sectional analysis, 2009-2023.

Intimate partner violence represents a persistent and complex threat to both public health and public security, with far-reaching consequences for morbidity, mortality, and health system capacity. Despite its magnitude, comprehensive analyses capable of capturing long-term epidemiological trends and relational dynamics of intimate partner violence remain limited, particularly in middle-income countries. This study provides a comprehensive national assessment of intimate partner violence in Brazil, integrating temporal trends, sociodemographic shifts, relationship characteristics, and indicators of violence severity and lethality. We conducted a descriptive cross-sectional analysis of 921,305 cases of intimate partner violence registered in national surveillance systems between 2009 and 2023. Analyses examined changes over time in victims' sociodemographic profiles and assessed contextual and clinical indicators of violence severity, including health care referral and deaths directly or indirectly attributable to intimate partner violence. The findings reveal a marked and sustained increase in reported cases over time, accompanied by substantial shifts in victim profiles and distinct epidemiological patterns according to relationship dynamics. Importantly, differentiated risks of severe and lethal violence across perpetrator types underscore the substantial burden imposed on health services and highlight critical intersections between health and public security. By leveraging a large, nationally representative dataset over an extended period, this study advances the epidemiological understanding of intimate partner violence in Brazil and provides robust, policy-relevant evidence to inform integrated public health and public security strategies aimed at preventing violence, reducing lethality, and mitigating its long-term societal impact.