Prospectively estimating the age of initiation of e-cigarettes among U.S. youth: Findings from the population assessment of tobacco and health (PaTh) study, 2013-2017.

Introduction:
This text provides an analysis of the Population assessment of Tobacco and health (PaTh) study, a nationally-representative survey of youth and adults in the US. The study estimates the distribution of the age of first reporting of e-cigarette use outcomes among youth never e-cigarette users overall, by sex and by race/ethnicity, prospectively. The key points include the study design, the outcomes measured, and the results of the analysis.

Key Points:

* The study used data from the PaTh youth dataset across waves 1 (2013-2014), 2 (2014-2015), 3 (2015-2016), and 4 (2016-2017).
* Four outcomes were examined: age of first report of susceptibility to use, ever use, past 30-day use, and "fairly regular" e-cigarette use.
* Weighted survival analyses for interval censoring accounting for the complex survey design were implemented.
* among youth non-susceptible to e-cigarettes, 50.2% became susceptible to e-cigarette use by age 18. There were no statistically significant differences in the age of first report of susceptibility to e-cigarette use by sex or by race/ethnicity in this nationally representative sample of U.S. youth.
* among never users, 41.7%, 23.5% and 10.3% initiated ever, past 30-day and "fairly regular" e-cigarette use by the age of 18, respectively.
* Boys had a higher risk of first reporting ever, past 30-day and "fairly regular" e-cigarette use at earlier ages than girls.
* Non-hispanic Blacks and Other racial/ethnic groups were less likely than Non-hispanic Whites to initiate ever e-cigarette use at earlier ages, and there was no difference between Non-hispanic Whites and hispanics.
* hispanic, Non-hispanic Black and Other racial/ethnic youth were less likely to first report past 30-day use and "fairly regular" e-cigarette use at earlier ages than Non-hispanic White youth.

Main Message:
This study provides important information on the ages at which youth first report e-cigarette use behaviors, which can be used to inform interventions and policy decisions. The findings suggest that interventions should be tailored to specific windows of opportunity before youth begin using e-cigarettes or escalating their use. The study also highlights disparities in e-cigarette use by sex and race/ethnicity, which should be considered when designing interventions and regulations. Overall, the study emphasizes the need for continued monitoring and research on e-cigarette use among youth.

Pérez a, Bluestein M, Chen B, Perry CL, harrell MB. Prospectively estimating the age of initiation of e-cigarettes among U.S. youth: Findings from the population assessment of tobacco and health (PaTh) study, 2013-2017. Journal of biometrics & biostatistics. 2020;11(4).