Dyadic patterns of abstinence from smoking in dual-smoking couples enrolled in a pilot randomized clinical trial

Abstract

Objective: Despite the positive role of social relationships in behavior change, dyadic interventions for smoking have not been consistently successful. This owes, in part, to the fact that dual-smoking cohabiting couples share similar routines, environments, and relational dynamics that can undermine quitting efforts. We adopted an exploratory and descriptive approach to identify distinct profiles of smoking abstinence within dyads, how relationship dynamics relate to these patterns, and whether these patterns predict smoking status at follow-up.

Method: We utilized preexisting data from a pilot RCT examining the effects of partner-involved financial incentives on dyadic abstinence. Both members of 95 dual-smoking couples (52% female, 73% White, M_age = 42.39, SD = 10.57) recruited between 2021 and 2022 provided baseline information about their relational and motivational dynamics, followed by 10 weeks of daily reports of smoking behavior, and biochemically verified quit status at follow-up.

Results: Latent growth mixture models suggested four patterns of dyadic abstinence: Concordant abstainers, Discordant abstainers, Discordant nonabstainers, and Concordant nonabstainers. Treatment arm and motivational and relational dynamics predicted the probability of following specific dyadic patterns of behavior change, and dyadic patterns of change predicted individual and couple quitting status at follow-up.

Conclusions: Our findings underscore the importance of considering that treatment will facilitate coordinated dyadic behavior change for some couples but not all and emphasize the need to better understand when and how mechanisms support long-term abstinence. More work is needed to investigate whether these patterns generalize across samples with more diverse sociodemographic and health characteristics. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Trial registration: ClinicalTrials.gov NCT04832360.

Figure 1

Fitted Growth Trajectories From Days 8 through 70 for Estimated Latent Classes

Figure 2. Target’ and Partner’ Standardized Scores on Baseline Variables, by Class

Note. Target’ and Partner’ standardized average responses on baseline constructs, by class. Averages were separately computed for Target and Partner and then standardized for each variable within each Target and Partner groups. Values above 0 reflect higher-than-average levels on that variable for that member of the dyad. Values below 0 reflect lower-than-average levels on that variable for that member of the dyad.

Figure 3. Odds Ratios and 95% Confidence Intervals for Multinomial Logistic Regressions Predicting Probability of Latent Class Membership

Note. Circles represent odds ratios; whiskers represent 95% confidence intervals. Each graph refers to the higher or lower odds (horizontal axis) of class membership (label before “vs.”) relative to the reference class (label after “vs.”) as Target- or Partner-reported levels on baseline variables (vertical axis) increase.