Contingency Management for Smoking Cessation Among Adults Experiencing Homelessness
Dian Gu, Deepalika Chakravarty, Jordan Cuby, Sharon Hall, Maxine Stitzer, Margot Kushel, Fan Xia, Maya VijayaraghavanImportance
More than 70% of people experiencing homelessness report current smoking. Contingency management (CM) interventions that provide financial incentives for smoking cessation have shown short-term promise, but extended CM interventions have not been well studied in this population.
Objective
To assess the feasibility and preliminary efficacy of an extended 6-month CM intervention for smoking cessation among adults experiencing homelessness.
Design, Setting, and Participants
This pilot parallel 2-group randomized clinical trial was conducted in 3 safety-net clinics in San Francisco, California. Adults experiencing homelessness who smoked cigarettes and intended to quit within 6 months were enrolled from November 8, 2021, to June 27, 2023. Participants were followed up for 6 months, completed 24-week follow-up on January 9, 2024, and completed exploratory 52-week follow-up on May 21, 2024. Data were analyzed between June 1, 2024, and December 31, 2025.
Interventions
Participants were randomized to extended CM or a control condition. The CM group received escalating gift card incentives for carbon monoxide (CO)–verified abstinence, starting at $13 and increasing by $0.50 for each negative test result for 6 months. Control participants received $5 per visit regardless of abstinence.
Main Outcomes and Measures
The preliminary efficacy outcome was 7-day point prevalence abstinence (PPA; CO-verified self-report of abstinence). The secondary outcome was repeated 7-day PPA.
Results
Of 83 participants, 42 were randomized to CM and 41 to a control. The mean (SD) age was 47.0 (10.8) years, and 53 participants (63.9%) were men. At 6 months, 7-day PPA was 31.0% in the CM group and 12.2% in the control group. After adjustment for covariates and with missing data treated as smoking, participants in the CM group had higher odds of achieving 7-day PPA at 6 months than those in the control group (adjusted odds ratio, 3.24 [95% CI, 1.03-10.19]; P = .04).
Conclusions and Relevance
In this pilot randomized clinical trial of adults experiencing homelessness, an extended CM intervention was feasible to implement and was associated with higher odds of 7-day PPA than the control condition. These findings suggest that extended CM may be a promising strategy for supporting smoking cessation in this population, but larger trials are needed to confirm efficacy.
Trial Registration
ClinicalTrials.gov Identifier: