E-Cigarette, Cigarette, and Dual Use in Korean Adolescents: A Test of Problem Behavior Theory.

E-cigarettes are becoming increasingly popular among adolescent cigarette users. However, little is known about the various factors related to adolescents' use of e-cigarettes, cigarettes, or both in South Korea. Using nationally representative data from the 2017 Korea Youth Risk Behavior Web-based Survey, this study examined the possible problem behavior theory factors that contribute to (1) current e-cigarette use among those who have ever used cigarettes (), (2) current cigarette use among those who have ever used e-cigarettes (), and (3) current dual use among current cigarette or e-cigarette users (). In all three models, our analysis showed that tobacco accessibility and sexual intercourse were significant factors. For , reasons for using e-cigarettes and alcohol use were correlated with current cigarette use. Except for gender, the significant factors, which included secondhand smoke exposure at home and school type, were the same in and . Based on these findings, we encourage the South Korean government to pay close attention to potential increase in dual use among adolescents and to take the necessary steps in addressing adolescent e-cigarette use in tobacco prevention and control programs.