ObjectiveRegulating health behavior change often occurs in a dyadic context of romantic relationships. Dyadic approaches to standard health behavior change models are, however, barely considered. We investigated volitional processes of the Health Action Process Approach model for two health behaviors within a dyadic context of romantic couples. Specifically, we tested whether day-to-day volitional self-regulation predicted one’s own and one’s partner’s cigarettes smoked (Study 1) and physical activity (Study 2).MethodsIn two dyadic intensive longitudinal studies (Study 1: 83 dual-smoker couples intending to jointly quit smoking; Study 2: 61 overweight couples intending to become physically active), heterosexual partners independently reported on intention, self-efficacy, action planning, and action control in end-of-day diaries. In Study 1, daily number of cigarettes smoked was assessed via self-report. In Study 2, daily moderate-to-vigorous physical activity (MVPA) was assessed objectively via accelerometers. In both studies, dyadic cross-lagged intensive longitudinal analyses based on the Actor-Partner Interdependence Model were applied.ResultsAcross both studies, individual’s own volitional self-regulation positively predicted one’s own health behavior (less cigarettes smoked and more MVPA). One’s partner’s action control and intention also positively predicted one’s own health behavior. A marginal partner effect for self-efficacy was found in the context of smoking only.ConclusionsBehavioral self-regulation is not only relevant for individuals themselves, but some volitional processes may spill over to their partners. This highlights the need to specify couple-level processes involved in health behavior change, and to consider a social context of self-regulation.

Introduction:Smoking individuals often have a romantic partner who also smokes. Social

The findings are in line with previous results, indicating invisible support to have beneficial relations with affect. However, results emphasize the need for further prospective daily diary approaches for understanding the dynamics of invisible support on smoking cessation. Statement of contribution What is already known on this subject? Social support receipt from a close other has proven to have emotional costs. According to current studies, the most effective social support is unnoticed by the receiver (i.e., invisible). There is empirical evidence for beneficial effects of invisible social support on affective well-being. What does this study add? Confirming benefits of invisible social support for negative affect in a health behaviour change setting Providing first evidence for detrimental effects of invisible social support on smoking.

Invisible support and invisible control may serve as protective buffers for negative affect in a health-behavior change context for male partners of dual-smoker couples. Future research should clarify under what conditions invisible exchanges unfold positive effects on partners' well-being and health behavior in different health contexts.

Received emotional support seems to play a key role in dual-smoker couple's abstinence, whereas provided support does not seem to make a difference in successful quitting in dual-smoker couples.

This article demonstrates that mastery experiences and self-efficacy show a reciprocal relationship within smokers during a quit attempt in a day-to-day design, as well as contagion effects in couples when both partners try to quit simultaneously. Statement of Contribution What is already known on this subject? Self-efficacy is one of the strongest correlates of quitting smoking. Despite the assumptions on how self-efficacy is built formulated by Bandura two decades ago, there is only little empirical evidence on the origins of self-efficacy. The open research questions for these two studies were whether mastery experiences (experiencing success with the new behavior) and vicarious experiences (seeing others succeed) facilitate the smoking cessation process, whether mastery experiences and self-efficacy affect one another reciprocally and whether intimate partners serve as role models for each other. What does this study add? Mastery experiences and self-efficacy are mutually depended on a day-to-day basis within the smoking cessation process. Effects of mastery experiences fade rapidly, indicating that constant successes are needed to keep up self-efficacy. Dual-smoker couples show similar changes in a contagious way - if mastery experiences increase in one person, mastery experiences increase in the partner; if self-efficacy increases in one person, self-efficacy increases in the partner, too. No support for vicarious experiences (mastery experiences in one person affecting self-efficacy in the partner and vice versa) as sources of self-efficacy in the quitting process was found.

A common form of social regulation of an individual's health behavior is social control. The contextual model of social control assumes that higher relationship quality goes along with more beneficial effects of social control on health behavior. This study examined potential differential moderating effects of different dimensions of relationship quality on the associations between positive and negative social control and smoking behavior and hiding smoking. The sample consisted of 144 smokers (n = 72 women; mean age = 31.78, SD = 10.04) with a nonsmoking partner. Positive and negative social control, dimensions of relationship quality consensus, cohesion and satisfaction, numbers of cigarettes smoked (NCS), hiding smoking (HS), and control variables were assessed at baseline. Four weeks later NCS and HS were assessed again. Only for smokers with high consensus, but not cohesion and satisfaction, a negative association between positive control and NCS emerged. Moreover, smokers with high consensus tended to report more HS when being positively and negatively socially controlled. This also emerged for cohesion and positive control. Satisfaction with the relationship did not display any interaction effects. This study's results emphasize the importance of differentiating not only between positive and negative social control but also between different dimensions of relationship quality in order to gain a comprehensive understanding of the dynamics in romantic dyads with regard to social regulation of behavioral change.

BackgroundTobacco smoking remains one of the biggest public health threats. Smartphone apps offer new promising opportunities for supporting smoking cessation in real-time. The social context of smokers has, however, been neglected in smartphone apps promoting smoking cessation. This randomized controlled trial investigates the effectiveness of a smartphone app in which smokers quit smoking with the help of a social network member.MethodsThis protocol describes the design of a single-blind, two-arm, parallel-group, intensive longitudinal randomized controlled trial. Participants of this study are adult smokers who smoke at least one cigarette per day and intend to quit smoking at a self-set quit date. Blocking as means of group-balanced randomization is used to allocate participants to intervention or control conditions. Both intervention and control group use a smartphone-compatible device for measuring their daily smoking behavior objectively via exhaled carbon monoxide. In addition, the intervention group is instructed to use the SmokeFree Buddy app, a multicomponent app that also facilitates smoking-cessation specific social support from a buddy over a smartphone application. All participants fill out a baseline diary for three consecutive days and are invited to the lab for a background assessment. They subsequently participate in an end-of-day diary phase from 7 days before and until 20 days after a self-set quit date. Six months after the self-set quit date a follow-up diary for three consecutive days takes place. The primary outcome measures are daily self-reported and objectively-assessed smoking abstinence and secondary outcome measures are daily self-reported number of cigarettes smoked.DiscussionThis is the first study examining the effectiveness of a smoking cessation mobile intervention using the SmokeFree Buddy app compared to a control group in a real-life setting around a self-set quit date using a portable objective measure to assess smoking abstinence. Opportunities and challenges with running studies with smoking participants and certain design-related decisions are discussed.Trial registrationThis trial was prospectively registered on 04/04/2018 at ISRCTNregistry: ISRCTN11154315.