Mechanisms of Change in a Randomized Control Pilot Study of Partner-Involved Financial Incentive Treatments for Dual-Smoking Couples

OBJECTIVE: Dual-smoker couples exhibit highly interdependent smoking behaviors, less frequent quit attempts, higher risk of relapse, and lower cessation rates. Financial incentive treatments are a promising form of intervention that lead to abstinence and can be adapted to address the motivational and relationship obstacles that dual-smoker couples face. METHOD: We enrolled 95 dual-smoker couples (total n = 190) in a randomized controlled trial (National Clinical Trials 04832360) to investigate the potential mechanisms by which two versions of partner-involved financial incentive treatments (combined in analyses) might facilitate quitting relative to a no-incentive control. Dyadic structural equation modeling tested whether the dyadic interventions impacted the likelihood of individual and couple-level cessation and whether these effects were mediated by individual (i.e., motivation) and relationship (i.e., partner support) processes. RESULTS: The results suggest that self-directed and partner-directed motivation changed in response to partner-involved financial incentive treatments. Change in self-directed motivation mediated the effect of the intervention on individual and joint abstinence at follow-up; partner-directed motivation also mediated the effect of the intervention on joint abstinence at follow-up. CONCLUSIONS: Our findings highlight the benefits of dyadic adaptations of treatments for dual-smoker couples and point to potential motivational mechanisms of behavior change. (PsycInfo Database Record (c) 2025 APA, all rights reserved).