Abstract
INTRODUCTION: Contingency management (CM) is an incentive-based approach that has demonstrated efficacy for smoking cessation in various populations. There is an unmet need for feasible and effective smoking cessation interventions in people with HIV (PWH). The purpose of this study was to assess the efficacy of prize-based CM for smoking cessation in PWH using a Sequential Multiple Assignment Randomization Trial (SMART) design selected to tailor intervention intensity based on early treatment response. METHODS: During phase I, 129 participants were randomly assigned to high-magnitude prize CM (HM-CM) or standard of care (SoC) for 4 weeks. Participants who did not reduce smoking were randomized in phase II to continued counseling with HM-CM plus monitoring support or only continued monitoring support for 8 weeks. Participants who reduced smoking were randomized to booster monitoring with low-magnitude CM or no additional care. Outcomes were biochemically verified smoking reduction and 7-day abstinence prevalence at posttreatment, 6-month, and 12-month follow-up. RESULTS: Phase I responders (based on biochemical indicators of smoking reduction) were significantly less likely to return to smoking (during treatment and at 6 and 12 months) if they received low-magnitude incentives. Notably, initial exposure to CM versus SoC did not increase the rate of phase I response, and high-magnitude incentives later in treatment did not lead to greater smoking cessation for early-treatment nonresponders. CONCLUSIONS: Weekly CM sessions in the first 4 weeks of smoking cessation intervention did not perform significantly better than SoC. However, brief booster CM sessions aimed at maintaining early smoking cessation hold clinical promise and warrant further investigation. IMPLICATIONS: This represents the first trial to examine the use of CM for smoking cessation among PWH within the context of a SMART design. Clinical Trial Registration: NCT01965405 (https://clinicaltrials.gov/study/NCT01965405).