The researchers sought to determine if e-cigarette use among 14-year-old adolescents who have never tried combustible tobacco is associated with risk of initiating use of three combustible tobacco products (cigarettes, cigars, and hookah). In the longitudinal study, the researchers assessed a school-based cohort at baseline (fall 2013, 9th grade, mean age = 14.1 years), at a 6-month follow-up (spring 2014, 9th grade), and a 12-month follow-up (fall 2014, 10th grade). Students at 10 Los Angeles public high schools were recruited through convenience sampling. Participants were students who reported never using combustible tobacco at baseline and completed follow-up assessments at 6 or 12 months (N = 2,530). At each time point, students completed self-reported surveys during in-classroom data collections.
Baseline e-cigarette use was associated with greater likelihood of use of any combustible tobacco product averaged across the two follow-up periods in the unadjusted analyses, and in the analyses adjusted for sociodemographic, environmental, and intrapersonal risk factors for smoking. Product-specific analyses showed that baseline e-cigarette use was positively associated with combustible cigarette, cigar, and hookah use. Although the study involved high school students in one city only and cannot be generalized to all teenagers, the data suggest that e-cigarette use may lead to use of tobacco products among teenagers.
Leventhal AM, Strong DR, Kirkpatrick MG, et al. Association of Electronic Cigarette Use With Initiation of Combustible Tobacco Product Smoking in Early Adolescence. JAMA. 2015;314(7):700-707.