LAUSR

This study sought to determine whether adolescents' e-cigarette risk perceptions, perceived benefits, and positive expectations, and vaping behavior changed after the electronic-cigarette or vaping product use-associated lung injury (EVALI) outbreak. This longitudinal survey studied 1539 high school students in suburban Philadelphia, PA in 11th and 12th grade, before and after the outbreak of EVALI cases in 2019. Adolescents who reported current nicotine vaping at baseline (versus those who did not) had a greater increase in risk perceptions (B = -0.31, p = 0.04) and a greater decrease in positive expectations (B = -1.30, p = 0.003) at follow-up. Adolescents who reported current marijuana vaping at baseline (versus those who did not) had greater perceived benefits (B = 2.19, p < 0.001), lower risk perceptions (B = 0.39, p < 0.001), and greater positive expectations of e-cigarette use (B = 1.43, p < 0.001) across time. Odds of current nicotine vaping at follow-up increased (OR = 1.61, 95% CI = 1.08, 2.41) for adolescents who maintained lower risk perceptions. Odds of current nicotine vaping at follow-up decreased (OR = 0.33, 95% CI = 0.21, 0.50) for adolescents whose positive expectations of e-cigarette use decreased. The odds of current marijuana vaping at follow-up decreased (OR = 0.64, 95% CI = 0.42, 0.98) for adolescents whose positive expectations of e-cigarette use decreased. Perceptions of the risks of e-cigarette use increased and positive expectations of e-cigarette use decreased after the EVALI outbreak. Adolescent risk perceptions and positive expectations of e-cigarette use are two potential targets to impact vaping behavior. Emphasizing the risks of e-cigarette use while decreasing positive expectations of use have the potential to reduce vaping behavior, and perhaps subsequent EVALI cases.