Changing patterns of cigarette and ENDS transitions in the US: a multistate transition analysis of youth and adults in the PATH Study in 2015-17 vs 2017-2019

IntroductionIt is unknown how recent changes in the tobacco product marketplace have impacted transitions in cigarette and electronic nicotine delivery system (ENDS) use. MethodsA multistate transition model was applied to 24,242 adults and 12,067 youth in Waves 2-4 (2015-2017) and 28,061 adults and 12,538 youth in Waves 4-5 (2017-2019) of the Population Assessment of Tobacco and Health (PATH) Study. Hazards for initiation, cessation, and product transitions were estimated in multivariable models, accounting for gender, age group, race/ethnicity, and daily vs non-daily product use. ResultsChanges in ENDS initiation/relapse rates from never, non-current, and cigarette-only use depended on age group, including among adults. Among youth never users, the 1-year probability of ENDS initiation increased after 2017 from 1.6% (95%CI: 1.4-1.8%) to 3.8% (95%CI: 3.4-4.2). Persistence of ENDS-only use (1-year probability of remaining an ENDS-only user) increased for youth from 40.7% (95%CI: 34.4-46.9%) to 65.7% (95%CI: 60.5-71.1%) and for adults from 57.8% (95%CI: 54.4-61.3%) to 78.2% (95%CI: 76.080.4%). Persistence of dual use similarly increased for youth from 48.3% (95%CI: 37.4-59.2%) to 60.9% (95%CI: 43.0-78.8%) and for adults from 40.1% (95%CI: 37.0-43.2%) to 63.8% (95%CI: 59.6-67.6%). Youth and young adult dual users became more likely to transition to ENDS-only use but middle-aged and older adults did not. ConclusionsENDS and dual use have become more persistent. Middle-aged and older adult dual users have become less likely to transition to cigarette-only use but not more likely to discontinue cigarettes. Youth and young adults are more likely to transition to ENDS-only use.