Single, Dual, and Triple Use of Cigarettes, e-Cigarettes, and Snus among Adolescents in the Nordic Countries.

New tobacco and nicotine products have emerged on the market in recent years. Most research has concerned only one product at a time, usually e-cigarettes, while little is known about the multiple use of tobacco and nicotine products among adolescents. We examined single, dual, and triple use of cigarettes, e-cigarettes, and snus among Nordic adolescents, using data of 15-16-year-olds (n = 16,125) from the European School Survey Project on Alcohol and other Drugs (ESPAD) collected in 2015 and 2019 from Denmark, Finland, Iceland, Norway, Sweden, and the Faroe Islands. Country-specific lifetime use of any of these products ranged between 40% and 50%, and current use between 17% and 31%. Cigarettes were the most common product in all countries except for Iceland, where e-cigarettes were remarkably more common. The proportion of dual and triple users was unexpectedly high among both experimental (24%-49%) and current users (31-42%). Triple use was less common than dual use. The users' patterns varied somewhat between the countries, and Iceland differed substantially from the other countries, with a high proportion of single e-cigarette users. More knowledge on the patterns of multiple use of tobacco and nicotine products and on the potential risk and protective factors is needed for targeted intervention and prevention efforts.