Buprenorphine adherence among a prospective cohort of homeless-experienced adults with opioid use disorder

Abstract

Introduction

People experiencing homelessness face high rates of opioid-related mortality. Buprenorphine is a medication that reduces opioid-related mortality, but adherence to this medication among people experiencing homelessness is not well-documented. This study assessed buprenorphine adherence and identified factors associated with it in this high-risk population.

Methods

We conducted a prospective cohort study of English- and Spanish-speaking adults ($\ge$18 years) enrolled in the Boston Health Care for the Homeless Program outpatient-based opioid treatment (OBOT) program from 1/6/2022–1/5/2023. Our primary outcome was buprenorphine adherence, measured by the percentage of days covered (PDC). We used multivariable linear regression to identify demographics, social determinants, and clinical characteristics independently associated with buprenorphine adherence.

Results

Of 139 participants, 23 % were female, 45 % were non-Hispanic White, 37 % were Hispanic, 13 % were non-Hispanic Black, and the mean age was 42 years. The mean PDC was 49.4 % over the 4-month follow-up period. Older age (beta=7.03 % per decade; 95 % CI=1.99 %-12.08 %), living in a residential treatment facility at baseline (vs. being unhoused; beta=14.6 %; 95 % CI=1.7 %-27.6 %), higher levels of baseline recovery (beta=0.77 % per one-point increase in the recovery score; 95 % CI=0.21 %-1.32 %), a higher maximum buprenorphine dose (>16 mg vs. $\le$16 mg; beta=13.1 %; 95 % CI=2.4 %-23.9 %), and receiving extended-release buprenorphine (beta=18.1 %; 95 % CI=4.3 %-31.9 %) were independently associated with a greater PDC.

Conclusions

Buprenorphine adherence in this cohort of homeless-experienced adults was approximately 50 % over 4 months. Proactive up-titration of buprenorphine dosing, consideration of extended-release formulation, and ensured access to buprenorphine in residential treatment settings may improve adherence in this marginalized population.