Background

Rates of suicide among people in prison are elevated compared with people of similar age and sex who are living in the community. Improving assessments and interventions to reduce suicide risk requires updated evidence on risk factors. We aimed to examine risk factors associated with suicide in prisoners.

Methods

We did an updated systematic review and meta-analysis of risk factors for suicide among people in prison. We searched five biblographic databases for articles published between Jan 1, 2006, and Aug 13, 2020, and one database for articles published between Jan 1, 1973, and Aug 13, 2020. Eligible studies reported risk factors in individuals who died by suicide while in prison and in controls from the general prison population. Two reviewers independently extracted data for each study using a standardised form. We calculated random-effects pooled odds ratios (ORs) for the association of suicide with demographical, clinical, criminological, and institutional risk factors, and investigated heterogeneity using subgroup and meta-regression analyses. This systematic review is registered with PROSPERO, CRD42020137979.

Findings

We identified 8041 records through our searches, and used 77 eligible studies from 27 countries, including 35 351 suicides, in the main analysis. The strongest clinical factors associated with suicide were suicidal ideation during the current period in prison (OR 15·2, 95% CI 8·5–27·0), a history of attempted suicide (OR 8·2, 4·4–15·3), and current psychiatric diagnosis (OR 6·4, 3·6–11·1). Institutional factors associated with suicide included occupation of a single cell (OR 6·8, 2·3–19·8) and having no social visits (OR 1·9, 1·5–2·4). Criminological factors included remand status (OR 3·6, 3·1–4·1), serving a life sentence (OR 2·4, 1·3–4·6), and being convicted of a violent offence, in particular homicide (OR 3·1, 2·2–4·2).

Interpretation

Several modifiable risk factors, such as psychiatric diagnosis, suicidal ideation during the current period in prison, and single-cell occupancy, are associated with suicide among people in prison. Preventive interventions should target these risk factors and include improved access to evidence-based mental health care. Understanding other factors associated with suicide might improve risk stratification and resource allocation in prison services.

Funding

Wellcome Trust, National Institute for Health Research Applied Research Collaboration Oxford and Thames Valley.

中文翻译：

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监狱自杀的危险因素：系统回顾和荟萃分析

 背景

与生活在社区中的同龄和性别的人相比，监狱中的人自杀率较高。改进评估和干预措施以降低自杀风险需要有关风险因素的最新证据。我们的目的是检查与囚犯自杀相关的风险因素。

 方法

我们对狱中人员自杀的危险因素进行了更新的系统回顾和荟萃分析。我们检索了 5 个书目数据库，查找 2006 年 1 月 1 日至 2020 年 8 月 13 日期间发表的文章，并检索了一个数据库，查找 1973 年 1 月 1 日至 2020 年 8 月 13 日期间发表的文章。符合条件的研究报告了自杀身亡者的危险因素。在监狱中并受到一般监狱人口的控制。两名评审员使用标准化表格独立提取每项研究的数据。我们计算了自杀与人口统计学、临床、犯罪学和机构风险因素之间关联的随机效应合并比值比 (OR)，并使用亚组和荟萃回归分析研究了异质性。本系统评价已在 PROSPERO 注册，CRD42020137979。

 发现

我们通过搜索确定了 8041 条记录，并在主要分析中使用了来自 27 个国家的 77 项符合条件的研究，其中包括 35 351 起自杀事件。与自杀相关的最强临床因素是当前入狱期间的自杀意念（OR 15·2，95% CI 8·5–27·0）、自杀未遂史（OR 8·2、4·4–15） ·3)，以及当前的精神病学诊断（OR 6·4、3·6–11·1）。与自杀相关的制度因素包括占据单个牢房（OR 6·8、2·3–19·8）和没有社交访问（OR 1·9、1·5–2·4）。犯罪学因素包括还押状态（OR 3·6、3·1–4·1）、服无期徒刑（OR 2·4、1·3–4·6）以及被判犯有暴力犯罪，特别是杀人罪（或 3·1、2·2–4·2）。

 解释

一些可改变的风险因素，例如精神病诊断、当前监狱期间的自杀意念以及单间牢房占用，与监狱中的自杀有关。预防性干预措施应针对这些风险因素，并包括改善获得循证精神卫生保健的机会。了解与自杀相关的其他因素可能会改善监狱服务的风险分层和资源分配。

 资金

威康信托基金、牛津大学国家健康研究所应用研究合作组织和泰晤士河谷。