Abstract
PURPOSE: Electronic nicotine delivery systems (ENDS) are adolescents' most commonly used tobacco product and young adults' second most used. Little is known about ENDS use alongside other tobacco products (polytobacco use) and whether exclusive ENDS users differ from polytobacco ENDS users. METHODS: In spring 2016, we surveyed a nationally representative sample of 3,517 13-25-year olds (36.9% 13-17-year olds), and examined sociodemographic and relative risk perceptions between two groups of past 30-day ENDS users: exclusive (only ENDS) and polytobacco (ENDS and at least one other tobacco product). RESULTS: 4.5% of adolescents and 10% of young adults reported past 30-day ENDS use (n = 281; analytic sample). ENDS users were 38.8% female and 70.6% white. Over half (55.9%) were polytobacco ENDS users. The most common patterns of polytobacco ENDS use were ENDS and cigarettes (11.5%), ENDS and cigars (7.7%), and ENDS, cigars, and waterpipe (5.2%). Those who perceived ENDS to be less harmful than cigarettes were more likely to be exclusive ENDS users than those who perceived ENDS to be as or more harmful than cigarettes (adjusted odds ratio = 2.6, confidence interval = 1.2, 5.7). There were no differences between ENDS groups on age, race, sex, parental education, sexual orientation, or ENDS use frequency. CONCLUSIONS: Just over half of ENDS users also used other tobacco products, increasing their risk for nicotine addiction and other health harms. The Food and Drug Administration is responsible for communicating product risk to consumers and should consider common patterns of use and relative risk perceptions in its ENDS public education efforts.