Initiation Patterns and Trends of E-Cigarette and Cigarette Use Among U.S. Adolescents.

Introduction:
This text provides an analysis of the initiation patterns and trends of e-cigarette and cigarette use among U.S. adolescents. The study uses data from 2015-2017 nationally representative samples of 8th and 10th grade students attending U.S. public and private schools. The objectives of the study are to examine the initiation patterns of e-cigarette and cigarette smoking, compare recent trends in initiation patterns for 2015, 2016, and 2017, examine sociodemographic differences in initiation patterns over time, and examine how initiation patterns are associated with cigarette-related perceptions, behaviors, and intentions.

Key Points:

* The study found that among lifetime e-cigarette or cigarette users, initiating e-cigarettes only was the most common initiation pattern (47.45%).
* The study found that the initiation pattern of e-cigarettes before cigarette use was the smallest group (6.89%) but increased from 2015 to 2017.
* The study found that e-cigarette before cigarette users were more likely to perceive cigarette use as risky but also more likely to currently smoke cigarettes compared to those who initiated cigarettes before e-cigarettes.
* The study found that both cigarette only initiators and e-cigarette only initiators were less likely to report future intentions to smoke compared to those who initiated cigarettes before e-cigarettes.
* The study found that sociodemographic characteristics, such as sex, race/ethnicity, parent education, U.S. Census geographical region, and metropolitan statistical area, were significantly different among the e-cigarette and cigarette use initiation groups.
* The study found that the perception of cigarette risk was lower among dual initiators compared to those who initiated e-cigarettes only.
* The study found that dual initiators were more likely to have current past 30-day cigarette use and future intentions to use cigarettes compared to cigarette only initiators.

Main Message:
The study highlights the changing initiation patterns related to e-cigarette and cigarette use among U.S. youth, with a significant increase in the number of adolescents initiating e-cigarettes only. The study also emphasizes the importance of examining the full spectrum of e-cigarette and cigarette sequence of initiation among adolescents and the need to consider initiation patterns in future research. The study suggests that intervention strategies may differ depending on whether an individual is a dual initiator and whether they initiate e-cigarette or cigarette use first. Overall, the study underscores the need for continued surveillance of e-cigarette and cigarette use initiation patterns among youth to maintain an accurate understanding of this public health issue and inform relevant interventions.

Evans-Polce RJ, Veliz P, Boyd CJ, McCabe SE. Initiation Patterns and Trends of E-Cigarette and Cigarette Use Among U.S. Adolescents. The Journal of adolescent health : official publication of the Society for Adolescent Medicine. 2020;66(1):27-33. doi:10.1016/j.jadohealth.2019.07.002