The report is a product of the VA/HSR Evidence Synthesis Program.

Engaging Veterans Experiencing Homelessness in Primary Care: A Systematic Review

Takeaway: Findings from this review highlight the value of engaging Veterans experiencing housing insecurity in any primary care. Homeless-tailored primary care may provide additional benefits over usual primary care for Veterans experiencing housing insecurity, including reduced inpatient hospitalizations and emergency department visits, while increasing the appropriate use of emergency care and resulting in overall cost savings and better care experiences. Future studies should examine the specific features of homeless-tailored primary care and how they affect outcomes.

Physical illness, mental illness, and substance use are more common among Veterans experiencing housing insecurity than stably housed Veterans. There is a need to understand the effect of primary care on Veterans experiencing housing insecurity. In 2010, VA implemented Patient-Aligned Care Teams (PACT), which provide coordinated, collaborative, interdisciplinary team-based care and build partnerships with Veterans. Since the implementation of PACT, VA also implemented Homeless Patient-Aligned Care Teams (HPACT), which function similarly to traditional PACT but incorporate additional team members such as social workers, substance use counselors, and homeless program staff, who offer services that can lead to permanent supportive housing.

In response to a request from VHA’s Office of the Assistant Under Secretary for Health—Clinical Services, the Providence Evidence Synthesis Program (ESP) Center examined the impact of primary care services, including PACT and HPACT, on clinical, healthcare utilization, and housing outcomes in Veterans experiencing housing insecurity. Investigators identified 19 relevant articles in Ovid MEDLINE, Cochrane, PsycINFO, CINAHL, Scopus, and ClinicalTrials.gov from inception until March 26, 2024. Eligible studies included Veterans ≥18 years of age with a history of experiencing housing insecurity. Studies were excluded if they consisted of home-based primary care, Geriatric PACT (GERIPACT), community primary care (i.e., primary care outside VA), or TriCare.

Summary of Findings

Four studies evaluated the effect of engaging Veterans experiencing housing insecurity in primary care, and 16 studies compared outcomes for Veterans experiencing housing insecurity in homeless-tailored primary care to usual primary care. The most frequently evaluated outcomes were emergency department use, satisfaction, and inpatient and special care use.

Effect of Engaging Veterans Experiencing Housing Insecurity in Primary Care

• Engaging Veterans experiencing housing insecurity in any primary care may significantly reduce hospitalizations and emergency department visits.
• Among Veterans experiencing housing insecurity, primary care visits may be high after initial engagement in primary care and then decrease over time.
• Studies provided insufficient evidence for housing or community integration outcomes for housing-insecure Veterans who are vs. are not established in primary care.
• Studies did not evaluate specialty care utilization, cost, return on investment, Veteran experience or satisfaction, or disease-specific outcomes.

Effect of Homeless-Tailored Primary Care vs. Usual Primary Care

• Homeless-tailored primary care may reduce inpatient hospitalizations and emergency department visits and increase appropriate use of emergency care. Additionally, homeless-tailored primary care may reduce mental health and substance use visits.
• Homeless-tailored primary care may result in better patient experiences and satisfaction.
• Homeless-tailored primary care may increase primary care costs and reduce emergency department and overall healthcare costs.
• There is no evidence for a difference in disease-specific outcomes for Veterans in homeless-tailored primary care compared to usual care.

Implications

Establishing Veterans experiencing housing insecurity in primary care likely prevents some acute events through better chronic disease management and diverts patients from unnecessary emergency department visits, which may translate into cost savings and a positive return on investment. Although homeless-tailored primary care provides more benefits than usual primary care, any primary care may be beneficial for Veterans. VA decision makers should consider developing a formal protocol that facilitates transitions between homeless program staff and primary care staff.

Limitations

The studies varied considerably in design and aims and used different terms to define the population of Veterans experiencing housing insecurity. The studies also used different lookback periods, did not examine whether the benefits of primary care were consistent across important subpopulations of Veterans, and were inconsistent in whether they reported cost, return on investment, disease-specific outcomes, and housing outcomes. Finally, all the studies relied on observational data to compare Veterans who do and do not engage in care, which raises selection bias concerns.

The ESP team was unable to differentiate between the types of homeless-tailored primary care described in the literature and was unable to understand the features of homeless-tailored primary care that affect outcomes. Additionally, it is possible that the same Veterans were included in multiple studies, and many of the studies were not designed to directly investigate the effect of primary care on outcomes.

Future Research

Future studies should investigate homeless-tailored primary care compared to usual primary care via a medical center-level randomized trial. Future studies should describe the specific features of tailored primary care and understand the aspects of tailored primary care that affect outcomes. Additional data on cost and cost-effectiveness would be particularly powerful in helping to understand the additional resources required to deliver homeless-tailored primary care, and there is also a need for future studies to consider the contextual factors that influence care, such as neighborhood factors and transportation access.

Citation: Rieke K, Caputo E, Baltich Nelson B, et al. Engaging Veterans Experiencing Homelessness in Primary Care: A Systematic Review. Washington, DC: Evidence Synthesis Program, Health Systems Research, Office of Research and Development, Department of Veterans Affairs. VA ESP Project #22-116; 2024.

To view the full report, go to https://www.hsrd.research.va.gov/publications/esp/homelessness-engagement.cfm.

How can VA leadership work with the ESP? Nominations for systematic review topics may be submitted to the program at any time. When you submit a topic nomination form, ESP Coordinating Center staff will work with you to determine the appropriate research approach and ESP product to address your questions of interest. Topics are selected and assigned to an ESP Center based on program capacity and alignment with VA national goals

This Management Brief is provided to inform you about recent HSR findings that may be of interest. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs. If you have any questions or comments about this Brief, please email CIDER. The Center for Information Dissemination and Education Resources (CIDER) is a VA HSR Resource Center charged with disseminating important HSR findings and information to policy makers, managers, clinicians, and researchers working to improve the health and care of Veterans.

This report is a product of VA/HSR's Evidence Synthesis Program (ESP), which was established to provide timely and accurate synthesis of targeted healthcare topics of particular importance to VA managers and policymakers; and to disseminate these reports throughout VA.

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