Association between observing peers vaping on campus and E-cigarette use and susceptibility in middle and high school students.

<bold>Background: </bold>This study examines the association between exposure to e-cigarette use on school campus and e-cigarette use behaviors among adolescents in the United States.<bold>Methods: </bold>Data were obtained from the 2019 National Youth Tobacco Survey. First, two multivariate logistic regression models examined the association between in-school exposure to e-cigarette use and ever and past 30-day (i.e., current) e-cigarette use. Next, a multivariate logistic regression model to examine the relationship between in-school exposure to e-cigarette use and susceptibility to use was conducted among a subsample (n = 11,958) of never e-cigarette users. Covariates included grade, race/ethnicity, marketing exposure, and ever use of other tobacco products.<bold>Results: </bold>Approximately 64.3 % of adolescents reported seeing someone use an e-cigarette on school campus; the most common locations being in the bathroom/locker room (34.4 %) and parking lot (34.0 %). In-school exposure to e-cigarette use was associated with greater odds of ever (Adj OR: 2.06; 95 % CI: 1.82-2.33) and current (Adj OR: 1.70; 95 % CI: 1.46-1.98) e-cigarette use among adolescents as well as greater odds of susceptibility to use (Adj OR: 2.00; 95 % CI: 1.82-2.20) among never e-cigarette users.<bold>Conclusions: </bold>Observing e-cigarette use on school campus was associated with greater odds of e-cigarette use and susceptibility. It is plausible that observing e-cigarette use on campus reinforces the social acceptability of adolescent e-cigarette use. Findings inform on the prevalence of e-cigarettes use on-campus as well as how this phenomenon may influence e-cigarette use/susceptibility among youth. The observed relationship highlights the role of schools in the efforts to reduce adolescent e-cigarette use. [ABSTRACT FROM AUTHOR]