Homelessness among US veterans has been a focus of research for over 3 decades. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, this is the first systematic review to summarize research on risk factors for homelessness among US veterans and to evaluate the evidence for these risk factors. Thirty-one studies published from 1987 to 2014 were divided into 3 categories: more rigorous studies, less rigorous studies, and studies comparing homeless veterans with homeless nonveterans. The strongest and most consistent risk factors were substance use disorders and mental illness, followed by low income and other income-related factors. There was some evidence that social isolation, adverse childhood experiences, and past incarceration were also important risk factors. Veterans, especially those who served since the advent of the all-volunteer force, were at greater risk for homelessness than other adults. Homeless veterans were generally older, better educated, and more likely to be male, married/have been married, and to have health insurance coverage than other homeless adults. More studies simultaneously addressing premilitary, military, and postmilitary risk factors for veteran homelessness are needed. This review identifies substance use disorders, mental illness, and low income as targets for policies and programs in efforts to end homelessness among veterans.

中文翻译：

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美国退伍军人无家可归的风险因素。

三十多年来，美国退伍军人的无家可归问题一直是研究的焦点。遵循系统评价和荟萃分析的首选报告项目（PRISMA）指南，这是第一次系统评价，总结了美国退伍军人无家可归风险因素的研究，并评估了这些风险因素的证据。1987 年至 2014 年发表的 31 项研究分为 3 类：较严格的研究、较不严格的研究以及将无家可归的退伍军人与无家可归的非退伍军人进行比较的研究。最强和最一致的风险因素是物质使用障碍和精神疾病，其次是低收入和其他与收入相关的因素。有证据表明，社会孤立、不良童年经历和过去的监禁也是重要的风险因素。退伍军人，尤其是自全志愿部队出现以来服役的退伍军人，比其他成年人面临更大的无家可归风险。与其他无家可归的成年人相比，无家可归的退伍军人通常年龄更大，受过更好的教育，并且更有可能是男性、已婚/已婚，并且拥有医疗保险。需要更多的研究同时解决退伍军人无家可归的前、军事和退役风险因素。本次审查将药物滥用障碍、精神疾病和低收入确定为旨在结束退伍军人无家可归现象的政策和计划的目标。