The prevalence of electronic cigarette (e-cigarette) use is rapidly increasing in adults and youth; however, little is known about the public health impact of their use. A debate over e-cigarettes has emerged in the literature; one side recognizes the potential benefit of e-cigarettes as a harm reduction tool, while others argue e-cigarette use may delay or deter smoking cessation due to dual use or increase the risk of initiation of conventional cigarettes among previous nonsmokers. Drawing on the Theory of Planned Behavior, this dissertation focused on attitudes, beliefs, and perceived social norms of e-cigarettes, as well as openness to conventional cigarette smoking among young adult users of the product.

Using a mixed methods approach, this dissertation analyzed secondary data from the 2012-2013 National Adult Tobacco Survey (NATS) as well as focus group data collected in five cities across the U.S. to better understand the relationship between e-cigarette use and cigarette smoking among young adults. In Study 1, quantitative analyses found non-cigarette smoking young adults who have tried e-cigarettes were more likely to report openness to cigarette smoking in the future compared to those who have not tried e-cigarettes (AOR= 2.4; 95% CI= 1.7-3.3). In Study 2, qualitative findings suggest that young adult exclusive e-cigarette users were less interested in conventional cigarette smoking, and overwhelmingly described negative aspects to cigarette smoking that appeared to become more salient as a result of their e-cigarette use. In Study 3, focus group participants expressed many positive attitudes towards e-cigarettes, and simultaneously reported a lack of information and knowledge about the products.

The relationship between e-cigarette use and cigarette smoking is complex and multifaceted, and influenced by a myriad of individual and social factors. Although quantitative findings suggest young adults who have used e-cigarettes compared to those who have not used e-cigarettes were more likely to report openness to future cigarette smoking, qualitative findings did not support the notion that young adult e-cigarette users (who may have prior experience with cigarette smoking) are open to future cigarette smoking. These findings provide a basis for further exploration of the association between e-cigarette use and cigarette smoking.