Housing and Support Intervention and Mortality Among Homeless Adults With Mental Illnesses: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Homelessness is an important risk factor for premature death, with individuals experiencing homelessness having substantially higher mortality rates than the general population. Objective: To assess the association of housing and support interventions with mortality among individuals experiencing homelessness and mental illnesses. Design, Setting, and Participants: This secondary analysis of a randomized clinical trial included 2255 homeless adults with mental illnesses. The study was conducted in 5 Canadian cities (Vancouver, Winnipeg, Toronto, Montreal, and Moncton). Recruitment took place from October 2009 to July 2011; mortality data were collected until March 30, 2019. Due to the complexity of accessing health administrative data, analyses were conducted and completed between February 2021 and December 2023. Exposure: Participants were randomized to receive either the Housing First (HF) intervention, which provided immediate permanent, scattered-site housing and support through intensive case management or assertive community treatment to chronically homeless individuals, or treatment as usual (TAU). Main Outcomes and Measures: Mortality rate ratios were ascertained at each site using health administrative databases. Adjusted hazard ratios were computed using Cox proportional hazard survival models. Random-effects meta-analysis was used to calculate pooled effect sizes across sites. Results: Of the 2255 total participants, 2108 (93.5%) were successfully linked with health administrative data; among them, 1434 (68.0%) were male, with a mean (SD) age of 40.6 (11.5) years. Mortality rates were not different in the HF compared with TAU groups (pooled log mortality rate ratio, -0.07; 95% CI, -0.36 to 0.22). The pooled adjusted hazard ratio comparing mortality in the HF and TAU groups was 0.83 (95% CI, 0.43-1.22). Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, the HF intervention was not directly associated with mortality risk. Research is needed to determine whether adjunctive interventions could reduce mortality among homeless individuals with mental illnesses. Trial Registration: isrctn.org Identifier: ISRCTN42520374.