The Use of Mobile Medical Units for Populations Experiencing Homelessness in the United States: A Scoping Review

With annual point-in-time counts indicating a rise in unsheltered homelessness in the United States, much attention has been paid to how to best provide care to this population. Mobile medical units (MMUs) have been utilized by many programs. However, little is known regarding the evidence behind their effectiveness. A scoping review is conducted of research on MMU provision of medical services for populations experiencing homelessness in the USA to examine the extent and nature of research activity, summarize available evidence, and identify research gaps in the existing literature. Following guidelines for scoping reviews, PubMed and Google Scholar were used to identify an initial 294 papers published from January 1, 1980, to May 1, 2023, using selected keywords, which were distilled to a final set of 50 studies that met eligibility criteria. Eligible articles were defined as those that pertain to the provision of healthcare (inclusive of dental, vision, and specialty services) to populations experiencing homelessness through a MMU in the United States and have been published after peer review. Of the 50 studies in the review, the majority utilized descriptive (40%) or observational methods (36%), with 4 review and 8 controlled studies and no completed randomized controlled trials. Outcome measures utilized by studies include MMU services provided (58%), patient demographics (34%), health outcomes (16%), patient-centered measures (14%), healthcare utilization (10%) and cost analysis (6%). The studies that exist suggest MMUs can facilitate effective treatment of substance use disorders, provision of primary care, and services for severe mental illness among people experiencing homelessness. MMUs have potential to provide community-based healthcare services in settings where homeless populations reside, but the paucity of randomized controlled trials indicates further research is needed to understand if MMUs are more effective than other care delivery models tailored to populations experiencing homelessness.