Use of an online smoking cessation community promotes abstinence: Results of propensity score weighting

For nearly 15 years, online communities have been an integral part of web-based smoking cessation programs (Cobb, Graham, Byron, Niaura, & Abrams, 2011). Online communities are social networks formed or facilitated through electronic media where members share experiences, ask questions, and provide emotional support (Eysenbach, Powell, Englesakis, Rizo, & Stern, 2004). “Created” (Cobb, Graham, & Abrams, 2010) or “intentionally designed” (Centola, 2013) communities within web-based cessation programs are distinct from social networks like Facebook in that they are most often comprised of strangers united by a common focus on quitting smoking. Online communities have evolved over time from the simple exchange of messages via email lists to complex networks with multiple modes of communication (e.g., forums, private messaging), self-representation (e.g., personal profiles, blogs, journals), and affiliations (e.g., friend lists, groups) (Cobb et al., 2010). The reach of online cessation communities to current and former smokers interested in quitting and maintaining abstinence is quite large. Several open-access web-based cessation programs based in the U.S. accrue hundreds of thousands of new registered users each year (Cobb & Graham, 2006; McCausland et al., 2011), many of whom are active in each program’s community. As of 2014, quitlines in 51 U.S. states and territories provide web-based cessation services and 26 include an online community (North American Quitline Consortium, 2014). Commercial programs reach thousands of smokers through employers and health plans (Alere Wellbeing Inc., 2014; National Jewish Health, 2015). The broad reach of these online communities – and others around the globe (van Mierlo, Voci, Lee, Fournier, & Selby, 2012; Wangberg, Nilsen, Antypas, & Gram, 2011) – makes understanding their impact on smoking cessation an important topic with both scientific and clinical implications. Several observational studies have reported that participation in online communities for cessation may be a key driver of abstinence (An et al., 2008; Cobb, Graham, Bock, Papandonatos, & Abrams, 2005; Richardson et al., 2013). For example, Cobb et al. (Cobb et al., 2005) found that individuals who participated in any aspect of the online community were more than three times as likely to be abstinent at 90 days as those who did not use the community. Quitters were more likely to have posted in forums, made an online buddy, and sent/received private messages than those who did not quit. Richardson et al. (2013) reported a dose response relationship between online community use and abstinence after controlling for intensity of use and numerous covariates. Though engagement in online social networks for cessation appears to be associated with higher rates of abstinence, the causal nature of this relationship has yet to be demonstrated. A primary challenge in determining the causal impact of participation in an online community is that it may not be feasible (or even prudent) to randomize participants to “use” or “not use” an online community. By definition, a community is a specific group of people who have developed relationships around a strong common interest (Millington, 2012). Interpersonal relationships meaningful enough to spur behavior change cannot be randomized. Individuals decide whether and how to participate in online communities based on their own unique needs and desires for information and support, their interest in finding “similar others”, and their ability to form interpersonal relationships, among myriad other reasons (Preece, Nonnecke, & Andrews, 2004). Given the lack of randomization, the compelling association between online community use and abstinence in these prior studies may be partly or entirely related to selection bias (Imai, Keele, Tingley, & Yamamoto, 2011). Any number of measured or unmeasured factors could confound an observed relationship between use of an online community and cessation. These factors could be personal (e.g., gender, use of other online networks), smoking-related (e.g., confidence in quitting, nicotine dependence), or other characteristics (e.g., social isolation, negative partner support) that may increase the likelihood of community participation. Self-selection is a vexing problem inherent to the study of online communities and social networks. This study examined whether participation in an online community for smoking cessation increased the odds of abstinence using propensity score methods to account for the lack of randomization. Data were drawn from one arm of The iQUITT Study, a randomized trial of Internet and telephone treatment for smoking cessation (Graham et al., 2011). Analyses addressed three questions: 1) What are the patterns of online community participation among users of a web-based smoking cessation program?; 2) What characteristics distinguish groups of online community users?; and 3) Is online community use predictive of abstinence in analyses that account for the possibility of self-selection bias?