Adolescent e-cigarette use has increased rapidly in recent years, but it is unclear whether e-cigarettes are merely substituting for cigarettes or whether e-cigarettes are being used by those who would not otherwise have smoked. To understand the role of e-cigarettes in overall tobacco product use, we examine prevalence rates from Southern California adolescents over 2 decades.
The Children’s Health Study is a longitudinal study of cohorts reaching 12th grade in 1995, 1998, 2001, 2004, and 2014. Cohorts were enrolled from entire classrooms in schools in selected communities and followed prospectively through completion of secondary school. Analyses used data from grades 11 and 12 of each cohort (N = 5490).
Among 12th-grade students, the combined adjusted prevalence of current cigarette or e-cigarette use in 2014 was 13.7%. This was substantially greater than the 9.0% adjusted prevalence of current cigarette use in 2004, before e-cigarettes were available (P = .003) and only slightly less than the 14.7% adjusted prevalence of smoking in 2001 (P = .54). Similar patterns were observed for prevalence rates in 11th grade, for rates of ever use, and among both male and female adolescents and both Hispanic and Non-Hispanic White adolescents.
Smoking prevalence among Southern California adolescents has declined over 2 decades, but the high prevalence of combined e-cigarette or cigarette use in 2014, compared with historical Southern California smoking prevalence, suggests that e-cigarettes are not merely substituting for cigarettes and indicates that e-cigarette use is occurring in adolescents who would not otherwise have used tobacco products.
RE: Misleading definitions of e-cigarette use cannot produce the sound science needed for regulation
In their recent study of the prevalence of e-cigarette use by adolescents, Barrington-Trimis et al. add use of combustible cigarettes and e-cigarettes to calculate the prevalence of “total adolescent tobacco product use” (1). However, e-cigarettes do not contain tobacco, even though the nicotine is extracted from tobacco, and many adolescents users use e-cigarettes that do not even contain nicotine (2). In addition, the authors define “current use” of tobacco or e-cigarettes as use of these products on one or more days in the past 30 days. This definition produces a category that is very heterogeneous, as it merges addicted users, regular users who are not addicted, occasional users, and experimenters who may have taken just one puff on a friend’s e-cigarette. For a product category that is recent and very innovative, experimentation is naturally frequent in adolescents, but most experimenters will not become regular users, and it is inaccurate to include them among current users (3). In fact, regular e- cigarette use among adolescent non-smokers is very rare (4). The authors, who are experienced researchers in this field, certainly know this, and it is therefore not only inaccurate but also misleading to calculate “total adolescent tobacco product use” in this way, when many of the adolescents counted by the authors as “tobacco users” actually used no tobacco and no nicotine. In their accompanying comment, Winikoff et al. call for political action, alarmed by the increasing numbers of adolescents “smoking cigarettes or e-cigarettes” (5), even though e-cigarettes emit no smoke (but an aerosol), contain no tobacco, and when used by adolescents, often contain no nicotine. Regulations and policies that are based on weak definitions of behaviors are unlikely to produce the expected results, but may very well produce results that are contrary to public health.
1) Barrington-Trimis JL, Urman R, Leventhal AM, et al. E-cigarettes, cigarettes, and the prevalence of adolescent tobacco use. Pediatrics. 2016;138(2). doi: 10.1542/peds.2015-3983.
2) Hamilton HA, Ferrence R, Boak A, et al. Ever use of nicotine and nonnicotine electronic cigarettes among high school students in Ontario, Canada. Nicotine Tob Res. 2015; 17(10):1212-8.
3) Saddleson ML, Kozlowski LT, Giovino GA, Homish GG, Mahoney MC, Goniewicz ML. Assessing 30-day quantity-frequency of U.S. adolescent cigarette smoking as a predictor of adult smoking 14 years later. Drug Alcohol Depend. 2016;162:92-8.
4) Bauld L. Young people and reduced risk products. Presented at the Global Forum on Nicotine, Warsaw, June 6, 2015.
5) Winickoff JP, Winickoff SE. Potential solutions to electronic cigarette use among adolescents. Pediatrics. 2016;138(2). doi/10.1542/peds.2016-1502.