Question: Is electronic cigarette (e-cigarette) use among tobacco-naive youths associated with subsequent risk of cigarette initiation?
Findings: In this cohort study using data from the Population Assessment of Tobacco and Health Study (2013-2016), youths whose first tobacco product was an e-cigarette were more likely to initiate cigarettes over 2 years of follow-up. At the population level, approximately 180 000 new ever smokers and 45 000 current smokers in the United States over 2 years may have started smoking combustible cigarettes after initiating e-cigarette use.
Meaning: Tobacco...