Am J Addict 2019 Apr 16. Epub 2019 Apr 16.
Center for the Study of Drugs, Alcohol, Smoking, and Health, Department of Health Behavior and Biological Sciences, School of Nursing, University of Michigan, Ann Arbor, Michigan.
Background And Objectives: The primary objectives were to: (1) examine the initiation sequence of e-cigarette use and cigarette smoking; (2) assess other substance use as a function of the initiation sequence of e-cigarettes and cigarettes; and (3) investigate the role of early e-cigarette initiation among US secondary school students.
Methods: Data were collected via self-administered questionnaires from independent 2015 and 2016 nationally representative cross-sectional samples of 8th grade, 10th grade, and 12th grade students (N = 36 410).
Results: The lifetime initiation sequence included: (1) e-cigarette use before cigarette smoking (1.7%); (2) e-cigarette use and cigarette smoking in same grade (4.2%); (3) cigarette smoking before e-cigarette use (6.1%); (4) e-cigarette use only (12.6%); (5) cigarette smoking only (3.6%); and (6) no e-cigarette use or cigarette smoking (71.8%). The risk of substance use was highest among dual users (regardless of initiation sequence), followed by cigarette smokers, e-cigarette users, and no e-cigarette use or cigarette smoking. The most prevalent initiation sequence of e-cigarette use involved initiating other substances before e-cigarettes, especially among older adolescents. Early initiation of e-cigarette use was associated with increased odds of substance use behaviors for all three age groups.
Discussion And Conclusions: Adolescents who report a history of both e-cigarette use and cigarette smoking should be considered at high risk for substance-related problems. Early initiation of e-cigarette use is a signal for other substance use.
Scientific Significance: Youth substance use prevention programs and prospective studies must take into account polysubstance use when addressing the relationships between e-cigarette use and cigarette smoking. (Am J Addict 2019;00:1-10).