BACKGROUND Mass media campaigns have been shown to be effective in reducing cigarette use. However, evidence is limited for whether campaigns can shift e-cigarette use among youth and young adults (YYA). To assess the impact of the truth anti-e-cigarette campaign, which focused on the effects of vaping on mental health, this study examines the relationship between campaign awareness and e-cigarette behaviour among YYA.

METHODS Data from weekly cross-sectional surveys of YYA aged 15-24 years from September 2021 to October 2022 were used for multilevel models assessing how weekly campaign awareness is related to intentions to use e-cigarettes and current e-cigarette use (past 30 days). Weekly campaign awareness was calculated by averaging individual-level awareness for each week. Control variables included individual-level campaign awareness, sociodemographics, perceived financial situation, parental smoking, sensation seeking, and mental health.

RESULTS Weekly campaign awareness ranged from 50% to 78%, with most weeks (77%) being within 65% and 75% of weekly campaign awareness. At weekly awareness levels between 65% and 75%, there was a significant association with lower intentions to use e-cigarettes. A dose-response relationship was observed for current use: compared with weeks with lower (<65%) awareness, weeks with awareness of 65-70% had 14% lower odds of current use, weeks with 70-75% awareness had 16% lower odds and weeks with >75% weekly awareness had 18% lower odds (p=0.018, p=0.009 and p=0.007, respectively).

CONCLUSIONS Findings from this analysis of weekly campaign awareness demonstrate that exposure to the truth anti-e-cigarette campaign is associated with significantly lower odds of intentions to use and current use of e-cigarette among YYA.