We found that participants whose cohabiting partners also smoked had lower dyadic efficacy than nonsmoking partners. This is consistent with prior research documenting the undermining effect of other smokers in the house when trying to quit (e.g., Walsh et al., 2007). In addition, in couples in which both partners were smokers, participants who believed their reference 4 partners were willing to quit with them had higher dyadic efficacy for quitting than those who did not. Because many smokers live or spend time with family and friends who also smoke (Di Castelnuovo et al., 2009), providing tools and resources to facilitate communication in dyads about cessation goals and efforts may be fruitful.

For example, when only one partner in a couple wants to quit smoking, it may be possible to elicit the partner��s support and plan strategies for limiting exposure to his or her smoking before beginning quit efforts. Specifically, working together as a couple to understand each partner��s divergent goals and planning together for success may be adaptive. Dyadic efficacy was modestly associated with self-efficacy for quitting. In particular, when we added self-efficacy to our cross-sectional regression models examining dyadic efficacy as a predictor of smoking-specific support behaviors and dyadic coping, dyadic efficacy remained a significant predictor of outcomes, while self-efficacy was not significant. These findings provide preliminary evidence that self-efficacy and dyadic efficacy are related but conceptually distinct constructs.

We found that dyadic efficacy was predictive of both increased self-efficacy for quitting over time and 7-day point prevalence abstinence rates. Because self-efficacy is an important precursor to behavior change (Bandura, 1986), a better understanding of the relationships between self-efficacy, dyadic efficacy, and support in couples in which one or both partners are trying to quit could be useful. If teamwork in couples can play a role in enhancing an individual��s sense of personal control over quit efforts, teamwork-focused smoking cessation interventions could be developed and tested. That those with higher dyadic efficacy had more success with quit efforts (as measured by 7-day point prevalence quit rates) over time is also promising as a first-step validation of this new measure.

That these findings became nonsignificant when we adjusted for additional covariates requires more research. This was an exploratory study in which we adapted items from an existing dyadic efficacy instrument to examine teamwork in couples in Cilengitide which at least one partner was motivated to quit smoking. There are important study limitations to consider as we only examined eight dyadic efficacy items at a single timepoint, limiting our ability to make conclusions about the properties of the instrument over time.