Background

Adverse childhood experiences (ACEs) are strong risk factors for homelessness and poor health and functioning. We aimed to evaluate the lifetime prevalence of ACEs and their associations with health-related and functioning-related outcomes among homeless adults.

Methods

In this systematic review and meta-analysis, we searched from database inception to Nov 11, 2020, for original and peer-reviewed studies in English that documented lifetime prevalence of ACEs or associations between ACEs and health-related or functioning-related outcomes. We selected studies if they included a definable group of homeless adults and measured at least four ACE categories. We calculated pooled estimates of lifetime prevalence of one or more ACEs and four or more ACEs with random-effects models. We used the leave-one-out method in sensitivity analyses and studied meta-regressions to explore potential moderators of ACE prevalence. We also did a narrative summary of associations between ACEs and health-related and functioning-related outcomes, as there were too few studies on each outcome for quantitative meta-analysis. This study is registered with PROSPERO, CRD42020218741.

Findings

We identified 2129 studies through systematic search, of which 29 studies (16 942 individuals) were included in the systematic review, 20 studies (10 034 individuals) were included in the meta-analysis for one or more ACEs, and 15 studies (5693 individuals) were included in the meta-analysis for four or more ACEs. Studies included samples of adults experiencing homelessness in the USA, Canada, and the UK; participants in the included studies were predominantly male (65·2%) and mean ages ranged between 18·3 and 58·1 years, but many studies did not report race, ethnicity, and sexual and gender minority data. Lifetime prevalence of one or more ACEs among homeless adults was 89·8% (95% CI 83·7–93·7) and the lifetime prevalence of four or more ACEs was 53·9% (45·9–61·7). Considerable heterogeneity was identified in both meta-analyses (I²>95%). Of the potential moderators analysed, the ACE measurement tool significantly moderated the estimated lifetime prevalence of one or more ACEs and four or more ACEs, and age also significantly moderated the estimated lifetime prevalence of four or more ACEs. In the narrative synthesis, ACEs were consistently positively associated with high suicidality (two studies), suicide attempt (three studies), major depressive disorder (two studies), substance misuse (two studies), and adult victimisation (two studies).

Interpretation

The lifetime prevalence of ACEs is substantially higher among homeless adults than among the general population, and ACE exposure might be associated with prevalence of mental illness, substance misuse, and victimisation. Policy efforts and evidence-based interventions are urgently needed to prevent ACEs and address associated poor outcomes among this population.

Funding

Rhodes Trust and Canadian Institutes of Health Research.

中文翻译：

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无家可归的成年人的不良童年经历和相关结果：系统评价和荟萃分析

背景

不良童年经历 (ACE) 是导致无家可归、健康和功能不佳的重要风险因素。我们旨在评估 ACE 的终生患病率及其与无家可归成年人的健康相关和功能相关结果的关联。

方法

在这项系统评价和荟萃分析中，我们从数据库开始到 2020 年 11 月 11 日搜索了原始和同行评审的英文研究，这些研究记录了 ACE 的终生患病率或 ACE 与健康相关或功能相关结果之间的关联。如果研究包括可定义的无家可归的成年人群体并测量了至少四个 ACE 类别，我们就会选择这些研究。我们使用随机效应模型计算了一种或多种 ACE 和四种或更多 ACE 的终生患病率的汇总估计值。我们在敏感性分析中使用留一法并研究了元回归，以探索 ACE 患病率的潜在调节因素。我们还对 ACE 与健康相关和功能相关结果之间的关联进行了叙述性总结，因为对每个结果进行定量荟萃分析的研究太少。

发现

我们通过系统搜索确定了 2129 项研究，其中 29 项研究（16 942 人）被纳入系统评价，20 项研究（10 034 人）被纳入一项或多项 ACE 的荟萃分析，15 项研究（5693 人） ) 被包括在四个或更多 ACE 的荟萃分析中。研究包括美国、加拿大和英国无家可归的成年人样本；纳入研究的参与者主要是男性 (65·2%)，平均年龄介于 18·3 和 58·1 岁之间，但许多研究没有报告种族、民族、性和性别少数数据。无家可归的成年人中一种或多种 ACE 的终生患病率为 89·8% (95% CI 83·7–93·7)，四种或更多 ACE 的终生患病率为 53·9% (45·9-61·7) . 在两个荟萃分析中都发现了相当大的异质性（I ² > 95%）。在分析的潜在调节因素中，ACE 测量工具显着调节了一种或多种 ACE 和四种或更多 ACE 的估计终生患病率，年龄也显着调节了四种或更多种 ACE 的估计终生患病率。在叙述综合中，ACE 始终与高自杀性（两项研究）、自杀未遂（三项研究）、重度抑郁症（两项研究）、物质滥用（两项研究）和成人受害（两项研究）呈正相关。

解释

无家可归的成年人中 ACE 的终生患病率远高于一般人群，并且 ACE 暴露可能与精神疾病、药物滥用和受害的患病率有关。迫切需要政策努力和循证干预措施来预防 ACE 并解决该人群中相关的不良结果。

资金

罗德信托基金和加拿大卫生研究所。