Tobacco cessation, mental health, and substance use in a community pharmacist-linked cessation program for people experiencing homelessness.

Introduction: The prevalence of tobacco use among people experiencing homelessness is 70 %. Mental health and substance use disorders are associated with tobacco use and pose challenges for tobacco cessation.

Methods: Between 2019 and 2024, we recruited 206 adults experiencing homelessness from three homeless shelters in San Francisco, California. Participants were enrolled in a 12-week pharmacist-linked smoking cessation program that involved pharmacist counseling and furnishing of nicotine replacement therapy (NRT) and brief cessation coaching by trained shelter staff. We examined the association of provision of tobacco cessation interventions with two outcomes-weekly cigarette consumption and quit attempts-using mixed effects Poisson and logistic regression models respectively. We ran separate models with baseline mental health conditions and substance use disorders and adjusted for age, gender, race-ethnicity, time to first cigarette after waking, and baseline cigarette consumption in all models.

Results: Adjusting for baseline mental health conditions and other covariates, the use of pharmacist-furnished NRT was associated with lower weekly consumption (Incidence Rate Ratio [IRR]: 0.74, 95 % Confidence Interval [CI]: 0.71-0.76) and increased weekly quit attempts (Adjusted Odds Ratio (AOR): 1.78, 95 % CI: 1.23-2.58). After adjusting for baseline substances used and other covariates, use of pharmacist-furnished NRT was associated with lower weekly consumption (IRR: 0.74, 95 % CI: 0.73-0.76) and increased weekly quit attempts (AOR: 1.99, 95 % CI: 1.45-2.74).

Conclusions: A community pharmacist-linked cessation program in homeless shelters was associated with reduced consumption and increased weekly quit attempts, highlighting its potential for scalability among people experiencing homelessness with high rates of co-occurring behavioral health conditions.