new study prospectively examined the role of electronic nicotine delivery systems (ENDS; also known as e-cigarettes) in initiating cigarette use among young adults. Participants were 2,558 U.S. college students involved in the first four waves of the Marketing and Promotions across Colleges in Texas project (Project M-PACT) who were between 18 and 25 years of age and reported never having used cigarettes at baseline. Variables examined in this study included age at first cigarette use, number of cigarettes smoked in lifetime, socio-demographic characteristics, cigarette use susceptibility, interpersonal factors (family-of-origin tobacco use and friend cigarette use), lifetime other tobacco use, and lifetime ENDS use. During the study period, 213 participants dropped out. The authors concluded students who remained in the study were more likely to be Asian and enrolled in a four-year university (versus a two-year school), and less likely to use other tobacco products and to be susceptible to other tobacco use. Two multivariable, multi-level discrete-time hazard models were used to evaluate whether ENDS use predicted cigarette initiation during the study period. Overall, results indicated 11% (n = 282) of participants reported cigarette use by wave 4. A significantly higher proportion of wave 1 ENDS users reported initiating cigarette use by wave 4, compared to wave 1 non-ENDS users (p < 0.001). Individuals who initiated cigarette use by wave 4 were more likely to be susceptible to cigarette use at wave 1, have a family member who used tobacco, have at least one friend who used cigarettes at wave 1, use at least one other type of tobacco at wave 1, and report ever using ENDS at wave 1, compared to participants who did not initiate cigarette use. The first model found lifetime ENDS use at wave 1 was associated with a 1.36 times greater odds of cigarette initiation, but the second model found a significant two-way interaction with other tobacco use. The authors interpreted this to mean that among students who used no other tobacco products at wave 1, ENDS use predicted greater odds of cigarette initiation (OR = 2.26, CI: 1.35-3.76), but among users of other tobacco products, ENDS use was not a significant predictor (OR = 1.13, CI: 0.81-1.58).

Take away: At baseline, students in this sample who reported only using electronic nicotine delivery systems (ENDS) had increased risk of cigarette initiation up to 1.5 years later, compared to non-tobacco users.

Citation: Loukas A, Marti CN, Cooper M, et al. (2017) Exclusive e-cigarette use predicts cigarette initiation among college students [published online ahead of print August 31 2017], Addictive Behaviors doi: 10.1016/j.addbeh.2017.08.023