Violence-related deaths among people released from incarceration: protocol for a systematic review

Mortality among people who have experienced homelessness: protocol for a systematic review and meta-analysis

INTRODUCTION

Homelessness is a major contributor to health inequalities. People who experience homelessness are at markedly increased risk of multiple and complex health morbidities which likely increase their susceptibility to early, preventable death. Despite this, the mortality burden in this group remains poorly understood, limited in part by insufficient synthesis of data at a global level. This systematic review will synthesise international literature examining rates of risk and protective factors for mortality among people who have experienced homelessness.

METHODS AND ANALYSIS

We will search MEDLINE, PsycINFO, Embase and PubMed for peer-reviewed cohort studies examining mortality among people who have experienced homelessness. No study eligibility restrictions will be placed on the date, country of origin, or language of publications, or age of the sample. We will assess the quality of included studies using the Methodological Standards for Epidemiological Research scale. Our measures of mortality will include: (A) incidence-all cause and cause specific, expressed as a crude mortality rate (CMR) per 1000 person-years, with 95% CI and (B) all cause and cause specific, indirectly standardised mortality ratios (SMRs) with 95%CI. Associations between risk and protective factors and all-cause and cause-specific mortality will be reported using pooled relative risk ratios with 95% CI. Where there are sufficient data, the influence of subgroup and methodological factors on CMRs, SMRs and predictive factors will be examined using meta-regression.

ETHICS AND DISSEMINATION

This study does not require institutional ethics review or approval as it will synthesise findings from published studies that have previously been granted relevant ethics approvals. Study findings will be disseminated through a peer-reviewed journal article, conference and seminar presentations. A plain language summary will be distributed through the authors' academic and professional networks.

PROSPERO REGISTRATION NUMBER

CRD42021272937.

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.