Health Care Access and Use Among Adults Experiencing Homelessness.

Importance: Demographic and policy changes have occurred since the last large, representative study of homeless adults in the 1990s, which may affect health care access and use. Objective: To describe the prevalence of poor health care access and short-term health care and use the Gelberg-Andersen Behavioral Model for Vulnerable Populations to assess the association between changes in homelessness with health care access and short-term care use. Design, Setting, and Participants: This representative survey of adults experiencing homelessness in California from October 2021 to November 2022 used multistage, venue-based, and respondent-driven sampling. Data were analyzed from May 2023 to December 2024. Exposures: Shelter status (predisposing vulnerable), insurance (enabling), impairment with activities of daily living (ADL; need), and illicit substance use during the previous 6 months (need). Main Outcomes and Measures: The study assessed self-reported no prior-year ambulatory care use and prior 6-month unmet health care need, unmet medication need, emergency department (ED) use, and hospitalization. Population prevalence estimates with Wald 95% CIs and multivariable Poisson regressions were calculated to compute prevalence ratios (PRs). Results: Thirty-two hundred adults completed the survey (mean age, 46.1 [95% CI, 45.3-46.9] years; 1965 cisgender men [67.2%], 1148 cisgender women [31.2%], and 57 transgender and gender queer individuals [1.6%]), of whom 2016 (77.6%) were unsheltered, 2609 (82.6%) were insured, 1056 (34.4%) had an ADL impairment, and 911 (37.1%) reported illicit substance use 3 or more times a week. A total of 1121 (39.1%) reported no ambulatory care use; 765 (24.3%) reported an unmet health care need and 714 (23.3%) an unmet medication need; 1252 (38.9%) used the ED; and 668 (22.0%) were hospitalized. Lack of ambulatory care use (PR, 1.71; 95% CI, 1.51-1.94) and unmet health care needs (PR, 1.19; 95% CI, 1.02-1.40) were more prevalent for those who were unsheltered. Lack of ambulatory care use (PR, 0.63; 95% CI, 0.57-0.70) and unmet health care needs (PR, 0.80; 95% CI, 0.67-0.95) were less prevalent for those with insurance. Unmet health care needs (PR, 2.13; 95% CI, 1.79-2.55), ED use (PR, 1.15; 95% CI, 1.02-1.30), and hospitalization (PR, 1.74; 95% CI, 1.40-2.17) were more prevalent for those with an ADL impairment. Lack of ambulatory care use (PR, 1.46; 95% CI, 1.19-1.79) and unmet health care needs (PR, 1.30; 95% CI, 1.08-1.55) were more prevalent for those who used illicit substances 3 or more times a week. Conclusions and Relevance: This cross-sectional study found that adults experiencing homelessness reported poor access to ambulatory care and a high prevalence of short-term care use, despite high rates of insurance. Changes in homelessness during the past 30 years were associated with worsened health care access and use.