Does source matter? Examining the effects of health experts, friends, and social media influencers on young adult perceptions of Instagram e-cigarette education messages

Purpose: Young adults' e-cigarette use is a leading public health concern. Using messages from credible sources can help improve message acceptance, yet little research has examined the role of source credibility on young adults' responses to e-cigarette education messages. Methods: We examined the impact of source on young adults' perceptions of e-cigarette education messages and e-cigarettes. In July 2022, we conducted an experimental study using an online sample of young adults (N=459, M-age=24.6) who were randomized to one of three source conditions: expert, friend, or influencer, and viewed e-cigarette education messages. We used one-way ANOVA to estimate the association between the conditions and outcomes (perceived source credibility, message trust, curiosity, use interests, perceived message effectiveness, beliefs, harm perceptions, and intentions to refrain). Results: The expert condition was associated with significantly higher perceived source credibility (vs. friend, influencer; p<0.001), message trust (vs. friend, influencer; p<0.001), and curiosity (vs. influencer; p's<0.05). Conclusions: Public health campaigns may leverage health experts to deliver e-cigarette education messages targeting young adults to improve effectiveness of the messages.