Incidence of all-cause mortality in prisons: research protocol for a global registry study and systematic literature review with meta-regression analyses.

INTRODUCTION: People in prison experience disproportionate health burdens compared with community-based populations, including elevated rates of infectious and non-communicable diseases, mental illness and substance use disorders. Previous studies have consistently shown increased rates of mortality following release from incarceration, particularly from external (unnatural) causes such as suicide and violence. However, evidence on mortality incidence during imprisonment is scarce, and many deaths may be preventable through targeted health and prevention interventions. This study aims to synthesise worldwide evidence on all-cause mortality incidence in prisons. METHODS AND ANALYSIS: We will conduct a worldwide registry study combined with a systematic literature review and meta-regression analysis. Eligible sources will report deaths among incarcerated people between 2005 and 2025 at the national or, where more appropriate, the subnational jurisdictional level. Mortality data will be retrieved from official reports of prison administrations and direct contact with prison authorities. Also, data from international databases and the scientific literature will be reviewed. Incidence rates of all-cause mortality per 100 000 person-years will be calculated and reported for each jurisdiction, alongside standardised mortality ratios comparing imprisoned populations with general population estimates. ETHICS AND DISSEMINATION: Since the study relies on anonymised routine data registries available from different sources, an exemption certificate was granted by the Ethics Committee of Diego Portales University (UDP) in Santiago, Chile. Findings will be submitted for publication in a peer-reviewed academic journal. TRIAL REGISTRATION NUMBER: https://osf.io/vkzae.