Sustaining Housing First After a Successful Research Demonstration Trial: Lessons Learned in a Large Urban Center.

Objectives: This study aimed to identify challenges and facilitators of sustaining a Housing First intervention at the conclusion of a research demonstration project in Toronto. Methods: This qualitative study included key informant interviews with organizational leaders (N=13) and focus groups with service teammembers (N=14) and programparticipants (N=9) of the At Home/Chez Soi Research Demonstration Project. Thematic analysis was used to identify key themes related to sustainability of Housing First beyond the demonstration phase. Results: Factors that helped secure long-term funding support for Housing First included the positive findings a rigorous evaluation, early stakeholder engagement, and strong local leadership. Reduced funding, poor intersectoral integration, and lack of central oversight threatened fidelity to the evidence-based model and challenged sustainability. Conclusions: Evidence-based complex interventions such as Housing First require robust intersectoral collaboration and flexible systems for funding and monitoring to ensure continuing model fidelity and responsiveness to changing contexts.