Lifetime prevalence of suicidal attempt among homeless individuals in North America: a meta-analysis

Background: : Homelessness is a compelling public health problem, and homeless individuals are at increased risk for attempting suicide. However, the reported lifetime prevalence of suicidal attempt among homeless individuals in North America varied considerably. Therefore, this meta-analysis aimed to estimate the pooled lifetime prevalence of suicidal attempt among homeless individuals in North America and explore factors that may moderate this estimation. Methods: : The protocol was registered in PROSPERO database (CRD42018102593). A systematic literature search was conducted in the electronic databases of PubMed, Embase, Web of Science, PsycINFO, and Google Scholar. Observational studies exploring the lifetime prevalence of suicidal attempt among homeless individuals in North America were included. Heterogeneity across studies was evaluated using the Cochran Q test and quantified using the I2 statistic. Subgroup analyses were performed to identify possible sources of heterogeneity. Results: : Twenty-two eligible studies with a total of 9,727 homeless individuals were included, of which 2,986 reported having attempted suicide in their lifetime. A high degree of heterogeneity (I2=96.4%, P<0.001) was observed, and the pooled lifetime prevalence was 31.83% (95% confidence interval: 26.87%-36.99%). Subgroup analyses showed that the heterogeneity was quite low when estimating the pooled lifetime prevalence of suicidal attempt among heterosexual (I2=0.0, P=0.401) and non-heterosexual homeless individuals (I2=0.0, P=0.405). Limitations: : All eligible studies were exclusively conducted in the US and Canada. Conclusions: : Nearly three tenths of homeless individuals in North America have attempted suicide in their lifetime, and the differences in sexual orientation might have contributed to the heterogeneity.