Breadth of Media Scanning Leads to Vaping among Youth and Young Adults: Evidence of Direct and Indirect Pathways from a National Longitudinal Survey.

Electronic cigarette use among youth and young adults has reached an epidemic proportion of growth. This study examined the direct and indirect effects of the breadth of media scanning about e-cigarette use on subsequent vaping behavior through interpersonal communication and changes in descriptive norm perceptions. We conducted a nationally representative longitudinal phone survey of 13- to 25-year-olds from June 2014 to March 2017, with 11,013 respondents who completed a baseline survey, among which 3,212 completed a follow-up 6 months later. The results from both cross-sectional and lagged analyses provided robust evidence to suggest that passive routine exposure to e-cigarette use content from more media outlets predicted increased likelihood of vaping among youth and young adults. High scanners were about twice as likely to vape as non-scanners (17% versus 9%). Mediation models using bootstrapping procedures found that breadth of scanning predicted higher descriptive norm perceptions which were associated with subsequent vaping; in addition, interpersonal communication mediated the relationship between breadth of scanning and changes in descriptive norm perceptions. These findings highlight the important roles of scanning, norm perceptions and interpersonal discussions in shaping cognition and behavior changes. The results also suggest an overall pro-e-cigarette public communication environment, which warrants further examination.