Violence-related deaths among people released from incarceration: systematic review and meta-analysis of cohort studies.

Background: People released from incarceration have an increased risk of violence-related death. As deaths from violence are a rare event, meta-analysis is needed to calculate reliable estimates of this risk. We examined the crude mortality rates (CMRs), standardised mortality ratios (SMRs), and predictive factors for violence-related deaths among people released from incarceration. Methods: In this systematic review and meta-analysis, we searched MEDLINE, PubMed, PsycINFO, Scopus, Web of Science, CINCH, and Criminal Justice Abstracts from inception to 14 September 2020 for cohort studies published in English that examined violence-related deaths occurring in the community following release from adult or youth incarceration. We used the Methodological Standard for Epidemiological Research (MASTER) scale to assess the quality of included studies. We conducted a random-effects meta-analysis to calculate pooled estimates of the CMRs and SMRs. Heterogeneity was assessed using univariable meta-regression. This review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42020209422). Findings: Our search identified 2,489 records, from which 11 studies met the eligibility criteria. The pooled CMR for violence-related deaths after release from incarceration was 78·7 per 100,000 person-years (95%CI 58·0-99·5). The pooled SMR was 7·6 (95%CI 2·4-12·8). The estimate of heterogeneity was high (I2≥99%) and the Cochran's Q test was significant (p<0·001) for the pooled CMR and SMR. Study design (prospective vs. retrospective; p=0·001) and type of incarceration facility (youth detention vs. prison; p=0·006) were identified as possible sources of heterogeneity for CMRs. Risk factors for violence-related death after release were reported in only five studies. These included being male (n=3), Black or Hispanic in the United States (n=3), and younger age at release from incarceration (n=2). Interpretation: People released from incarceration are almost eight times more likely to die from violence than the general population. Violence-related deaths are preventable, and the high rate at which they occur after release from incarceration represents an important public health issue requiring targeted, evidence-based response. Funding: None.