Diana Margot Rosenthal

Background Homeless populations (HPs) have difficulties obtaining necessary medical care, and primary health care service outreach (PHSO) might be useful to bridge this gap. Objective Using the Centre for Evidence-Based Management Critically Appraised Topics framework, to provide systematic evidence of the usefulness of PHSO interventions for HPs. Methods A systematic search was conducted in 4 electronic databases: PubMed, Web of Science, CINAHL, and Cochrane (publication dates between January 1980 and November 2020). In total, 2,872 articles were identified. Primary research about PHSO for HPs in high-income countries were included. Data were extracted from eligible studies, summarized, and collated into a narrative account. Results Twenty-four studies that described and evaluated PHSO interventions for adults experiencing homelessness were selected in the final synthesis. Most studies had a nonrandomized design. PHSO was found to successfully address some barriers to health care access for HPs through flexible appointments in convenient locations, fostering an understanding relationship between doctor and patients, and provision of additional basic necessities and referrals. Outreach was provided for a range of health care concerns, and several solutions to engage more HPs in primary care, improve continuity of care and to decrease the running costs were identified. Outreach also helped to implement preventative measures and reduced emergency service admissions. Conclusion Our review adds to the evidence that PHSO likely improves health care access for HPs. Further studies over longer time periods, involving collaborations with experts with lived experience of homelessness, and utilizing randomized study designs are needed to test outreach efficacy.