Impact of the e-cigarette era on cigarette smoking among youth in the United States: a population-level study.

Introduction:
This text discusses a population-level study examining the impact of the e-cigarette era on cigarette smoking among youth in the United States. The study uses data from the National Youth Tobacco Survey (NYTS) from 2002 to 2019 to model the prevalence of past 30-day cigarette smoking over time and compare trends before and after the onset of the e-cigarette era in 2014. The study also estimates the number of additional past 30-day cigarette smokers during the e-cigarette era.

Key Points:

* The study found that past 30-day cigarette smoking declined among all students from 2002 to 2013, but the decline slowed significantly following the onset of the e-cigarette era in 2014.
* The study estimates that the onset of the e-cigarette era corresponded to over 1.66 million more past 30-day cigarette smokers from 2015 to 2019.
* The study used interrupted time series analyses to examine changes in cigarette smoking over time and compare trends pre- and post-2014.
* The study applied models to the full sample and stratified by middle and high school.
* The observed number of current adolescent cigarette smokers post-2014 was compared to the predicted number, given trends in cigarette smoking prevalence observed pre-2014.
* The study found that the rate of decline in past 30-day cigarette smoking slowed significantly following the onset of the e-cigarette era in 2014.
* The study controlled for potential conflicts of interest and ensured ethical compliance.

Main Message:
The study provides evidence at a population-level for the "gateway effect" of e-cigarettes on cigarette smoking among youth. The onset of the e-cigarette era in 2014 corresponded to over 1.66 million more past 30-day cigarette smokers from 2015 to 2019, providing strong evidence that e-cigarettes are leading to an increase in cigarette smoking among youth. The study highlights the importance of regulatory measures to prevent youth access to e-cigarettes and reduce the "gateway effect" to cigarette smoking.

harrell MB, Mantey DS, Chen B, Kelder Sh, Barrington-Trimis J. Impact of the e-cigarette era on cigarette smoking among youth in the United States: a population-level study. Preventive medicine. 2022;164:107265. doi:10.1016/j.ypmed.2022.107265