Initial e-cigarette flavoring and nicotine exposure and e-cigarette uptake among adolescents

Objective: E-cigarettes are the most prevalent tobacco product used by adolescents. We sought to determine whether the presence of flavoring and/or the presence of nicotine at the first e-cigarette exposure predicted progression to current e-cigarette use (use in past 30 days) as well as escalation in use (number of days in the past 30 days) among adolescents. Methods: Adolescents from public high schools outside of Philadelphia, PA completed in-classroom surveys at baseline (9th grade) and at 6-month intervals for the following 18 months (fall 2018, beginning of 11th grade). Adolescents who reported ever having used e-cigarettes at baseline (N = 354) comprised the analytical sample. Results: We employed a two-part Latent Growth Curve Model including flavor, nicotine, and other covariates. Initial use of a flavored (vs unflavored) e-cigarette was associated with progression to current e-cigarette use (beta = 0.54, z = 2.09, p = 0.04) and escalation in the number of days of e-cigarette use (beta = 0.35, z = 2.58, p = 0.01) across the following 18 months. Initial use of an e-cigarette with nicotine (vs without nicotine) was associated with a greater number of days of e-cigarette use at baseline (beta = 0.49, z = 2.16, p = 0.03). Conclusions: The findings underscore the risk that flavoring and nicotine pose for progression beyond initial e-cigarette use. Regulations addressing flavoring and nicotine in e-cigarettes have the potential to reduce the number of adolescents who become current as well as frequent e-cigarette users.