Health Care Utilization among Homeless-Experienced Adults Who Were Seen by a Mobile Addiction Health Clinic in Boston, Massachusetts: A Quasi-Experimental Study.

Background: Mobile health clinics improve access to care for marginalized individuals who are disengaged from the healthcare system. This study evaluated the association between a mobile addiction health clinic and health care utilization among people experiencing homelessness. Methods: Using Medicaid claims data, we evaluated adults who were seen by a mobile addiction health clinic in Boston, Massachusetts from 1/16/18-1/15/19 relative to a propensity score matched control cohort. We evaluated both cohorts from four years before to one year after the index visit date with the mobile clinic. The primary outcome was the number of outpatient visits; secondary outcomes were the number of hospitalizations and emergency department (ED) visits. We used Poisson regression to compare changes in outcomes from before to after the index date in a quasi-experimental design. Results: 138 adults were seen by the mobile clinic during the observation period; 29.7% were female, 16.7% were Black, 8.0% Hispanic, 68.1% White, and the mean age was 40.4 years. The mean number of mobile clinic encounters was 3.1. The yearly mean number of outpatient visits increased from 11.5 to 12.1 (p = 0.43; pdiff-in-diff = 0.15), the number of hospitalizations increased from 2.2 to 3.0 (p = 0.04; pdiff-in-diff = 0.87), and the number of ED visits increased from 5.4 to 6.5 (p = 0.04; pdiff-in-diff = 0.40). Conclusions: The mobile addiction health clinic was not associated with statistically significant changes in health care utilization in the first year. Further research in larger samples using a broader set of outcomes is needed to quantify the benefits of this innovative care delivery model.

Drug Overdose Mortality Among People Experiencing Homelessness, 2003 to 2018.

Importance: Despite high rates of drug overdose death among people experiencing homelessness, patterns in drug overdose mortality, including the types of drugs implicated in overdose deaths, remain understudied in this population. Objective: To describe the patterns in drug overdose mortality among a large cohort of people experiencing homelessness in Boston vs the general adult population of Massachusetts and to evaluate the types of drugs implicated in overdose deaths over a continuous 16-year period of observation. Design, Setting, and Participants: This cohort study analyzed adults aged 18 years or older who received care at Boston Health Care for the Homeless Program (BHCHP) between January 1, 2003, and December 31, 2017. Individuals were followed up from the date of their initial BHCHP encounter during the study period until the date of death or December 31, 2018. Data were analyzed from December 1, 2020, to June 6, 2021. Main Outcomes and Measures: Drug overdose deaths and the types of drugs involved in each overdose death were ascertained by linking the BHCHP cohort to the Massachusetts Department of Public Health death records. Results: In this cohort of 60 092 adults experiencing homelessness (mean [SD] age at entry, 40.4 [13.1] years; 38 084 men [63.4%]), 7130 individuals died by the end of the study period. A total of 1727 individuals (24.2%) died of a drug overdose. Of the drug overdose decedents, 456 were female (26.4%), 194 were Black (11.2%), 202 were Latinx (11.7%), and 1185 were White (68.6%) individuals, and the mean (SD) age at death was 43.7 (10.8) years. The age- and sex-standardized drug overdose mortality rate in the BHCHP cohort was 278.9 (95% CI, 266.1-292.3) deaths per 100 000 person-years, which was 12 times higher than the Massachusetts adult population. Opioids were involved in 91.0% of all drug overdose deaths. Between 2013 and 2018, the synthetic opioid mortality rate increased from 21.6 to 327.0 deaths per 100 000 person-years. Between 2004 and 2018, the opioid-only overdose mortality rate decreased from 117.2 to 102.4 deaths per 100 000 person-years, whereas the opioid-involved polysubstance mortality rate increased from 44.0 to 237.8 deaths per 100 000 person-years. Among opioid-involved polysubstance overdose deaths, cocaine-plus-opioid was the most common substance combination implicated throughout the study period, with Black individuals having the highest proportion of cocaine-plus-opioid involvement in death (0.72 vs 0.62 in Latinx and 0.53 in White individuals; P < .001). Conclusions and Relevance: In this cohort study of people experiencing homelessness, drug overdose accounted for 1 in 4 deaths, with synthetic opioid and polysubstance involvement becoming predominant contributors to mortality in recent years. These findings emphasize the importance of increasing access to evidence-based opioid overdose prevention strategies and opioid use disorder treatment among people experiencing homelessness, while highlighting the need to address both intentional and unintentional polysubstance use in this population.

Experience with a Mobile Addiction Program among People Experiencing Homelessness.

A mobile addiction-focused outreach program designed to improve access to care for people experiencing homelessness was implemented in response to the opioid overdose crisis. This innovative program was readily accepted among participants and can inform the development of similar programs delivering addiction-focused care to people experiencing homelessness elsewhere.

Office-Based Addiction Treatment Retention and Mortality Among People Experiencing Homelessness.

Importance: People experiencing homelessness have been disproportionately affected by the opioid overdose crisis. To mitigate morbidity and mortality, several office-based addiction treatment (OBAT) programs designed for this population have been established across the US, but studies have not yet evaluated their outcomes. Objective: To evaluate treatment retention and mortality in an OBAT program designed specifically for individuals experiencing homelessness with opioid use disorder (OUD). Design, Setting, and Participants: A retrospective cohort study was conducted in the Boston Health Care for the Homeless Program (BHCHP). Participants included all adult patients (N = 1467) who had 1 or more OBAT program encounter at BHCHP from January 1 through December 31, 2018. Data analysis was conducted from January 13 to December 14, 2020. Exposures: Sociodemographic, clinical, and addiction treatment-related characteristics were abstracted from the BHCHP electronic health record. Main Outcomes and Measures: The primary outcome was all-cause mortality, identified by linkage to the Massachusetts Department of Public Health vital records. Multivariable Cox proportional hazards regression analyses were performed to evaluate baseline and time-varying variables associated with all-cause mortality. Secondary addiction treatment-related outcomes were abstracted from the electronic health record and included (1) BHCHP OBAT program retention, (2) buprenorphine continuation and adherence verified by toxicology testing, and (3) opioid abstinence verified by toxicology testing. Results: Of 1467 patients in the cohort, 1046 were men (71.3%) and 731 (49.8%) were non-Hispanic White; mean (SD) age was 42.2 (10.6) years. Continuous retention in the OBAT program was 45.2% at 1 month, 21.7% at 6 months, and 11.3% at 12 months. Continuous buprenorphine adherence was 41.5% at 1 month, 17.6% at 6 months, and 10.2% at 12 months, and continuous opioid abstinence was 28.3% at 1 month, 6.1% at 6 months, and 2.9% at 12 months. The all-cause mortality rate was 29.0 deaths per 1000 person-years, with 51.8% dying from drug overdose. Past-month OBAT program attendance was associated with lower mortality risk (adjusted hazard ratio, 0.34; 95% CI, 0.21-0.55). Conclusions and Relevance: Mortality rates were high in this cohort of addiction treatment-seeking homeless and unstably housed individuals with OUD. Although continuous OBAT program retention was low, past-month attendance in care was associated with reduced mortality risk. Future work should examine interventions to promote increased OBAT attendance to mitigate morbidity and mortality in this vulnerable population.