Use of Electronic Nicotine Delivery Systems or Cigarette Smoking After US Food and Drug Administration–Prioritized Enforcement Against Fruit-Flavored Cartridges

IMPORTANCE: The Center for Tobacco Products (CTP) of the US Food and Drug Administration prioritized its enforcement efforts against non–tobacco-, non–menthol- (fruit-) flavored cartridge electronic nicotine delivery systems (ENDS) in February 2020. OBJECTIVE: To evaluate adults’ use of ENDS and cigarette smoking following the CTP’s prioritized enforcement efforts against fruit-flavored cartridge ENDS. DESIGN, SETTING, AND PARTICIPANTS: In this population-based, nationally representative US cohort study, data were collected from the Population Assessment of Tobacco and Health Study from December 2018 to November 2019 (hereafter referred to as 2019) and/or from September 2020 to December 2020 (Adult Telephone Survey, hereafter referred to as 2020). Adults (aged ≥21 years) who used ENDS in the past 30 days and smoked cigarettes in the past 30 days or quit smoking cigarettes in the past year (n = 3173) were evaluated. Data were analyzed from January 1, 2022, to May 2, 2023. EXPOSURE: ENDS flavor-device combinations used. MAIN OUTCOMES AND MEASURES: Outcome measures were cross-sectional prevalence of ENDS flavor-device combinations used in 2019 (n = 2654) and 2020 (n = 519) and longitudinal transitions in cigarette smoking (cessation [no smoking in the past 30 days in 2020 among those who smoked in 2019; n = 876] and relapse [smoking in the past 30 days in 2020 among those who recently quit in 2019; n = 137]) as a function of ENDS flavor-device combination used in 2019. RESULTS: The sample in 2019 included 2654 individuals (55% male [95% CI, 53%-58%]). Among those who used ENDS and smoked cigarettes, fruit-flavored cartridge ENDS use decreased from 13.9% (95% CI, 12.1%-15.9%) in 2019 to 7.9% (95% CI, 5.1%-12.1%) in 2020 (P = .01), whereas fruit-flavored disposable ENDS use increased from 4.0% (95% CI, 3.1%-5.1%) in 2019 to 14.5% (95% CI, 11.6%-18.0%) in 2020 (P < .001). Patterns were similar among those who recently quit smoking. Neither cigarette cessation nor relapse rates differed between those who used ENDS that were vs were not prioritized for enforcement efforts (cessation: 23.4% [95% CI, 18.1%-29.7%] vs 26.4% [95% CI, 22.4%-30.8%]; adjusted odds ratio, 1.12; 95% CI, 0.57-2.21; relapse: 32.7% [95% CI, 17.1%-53.4%] vs 29.8% [95% CI, 20.3%-41.3%]; adjusted odds ratio, 0.96; 95% CI, 0.24-3.84). CONCLUSIONS AND RELEVANCE: In this nationally representative US cohort study of adults who smoked cigarettes and used ENDS, fruit-flavored cartridge ENDS use was nearly halved between 2019 and 2020. Cigarette cessation and relapse rates did not differ between those who used ENDS targeted by CTP and those who used other ENDS.