National Youth tobacco surveys (2014-2019) show increasing beliefs in the harm and relative addiction of e-cigarettes but decreasing associations between those beliefs and e-cigarette use.

BACKGROUND:To evaluate the potential efficacy of increasing harm and relative addiction beliefs in discouraging e-cigarette use, we examined how adolescents' beliefs about e-cigarettes have changed over 6 years and how the predictive validity of these beliefs has changed over time. METHODS:Using data from the 2014-2019 National Youth Tobacco Survey (NYTS) (grades 6-12; N = 117,472), we evaluated the association between adolescents' beliefs about the harm and relative addiction of e-cigarettes and current e-cigarette use, as well as susceptibility to use. Logistic regressions and pairwise contrasts were used to analyze changes in these beliefs and determine how well these beliefs predict ever use, current use, and susceptibility to use over time. RESULTS:E-cigarette harm and relative addiction beliefs tended to increase over time. In most years, these beliefs were negatively associated with e-cigarette use, including ever use, current use, and susceptibility to use. Interactions between these beliefs were also observed in some years such that harm belief better predicted use when e-cigarettes were also perceived as more addictive. Survey year also interacted with health harm and relative addiction beliefs such that the predictive validity of these beliefs for e-cigarette use decreased over time. CONCLUSIONS:Beliefs about e-cigarette harm and relative addiction have increased over time and predict use of, and susceptibility to, e-cigarettes among US adolescents. However, the predictive validity of these beliefs has decreased over time. Future research should explore the reasons for the decreased predictive validity of health beliefs in e-cigarette use and identify constructs that predict adolescent e-cigarette use over and above general harm and relative addiction beliefs.