Incidence, ecological factors, and temporal trends of prison homicides and suicides in Chile, 2000-2024

External (non-natural) causes of death are frequent in prison. This study aimed to assess the incidence, associated ecological factors, and changes over time of prison homicides and suicides in Chile between 2000 and 2024.

National and regional cases of homicides and suicides in prison were obtained by year through Transparency Council requests to the Chilean prison authority. Corresponding incidence data in the general population were retrieved from publicly available sources. Incidence rates were estimated per 100,000 person-years of imprisonment and compared between regions. The proportion of external causes of death among overall mortality in prison was also calculated. Prais-Winsten autoregressive models were used to analyze changes in incidence over time. Latent structures underlying the incidence were explored using principal component analysis (PCA).

Incidence rates of external causes of death were 148 (95% CI: 127-170) in southern, 142 (95% CI: 133-151) in central, and 86 (95% CI: 74-99) per 100,000 person-years in northern regions. A decreasing slope in the national homicide incidence was observed (ß=-12.26, p<0.0001), while several regions presented an increase (i.e., Los Ríos, a southern region; ß=21.57, p<0.0001). Suicide incidence remained stable over time (ß=0.44, p=0.385). Settings with higher proportions of individuals convicted of violent offences and southern regions faced an elevated risk of suicide (ß=18.63, p=0.007).

Prevention policies and interventions for external causes of death should prioritize southern regions, those with increasing incident rates and with high proportions of individuals sentenced for violent offences.