Abstract
INTRODUCTION: Young adults' e-cigarette use is associated with perceptions that e-cigarettes are less harmful or addictive than cigarettes, socially acceptable, and appealing. This study developed and tested vaping educational messages addressing these factors: 1) Harm Perceptions, 2) Addictiveness, 3) Social Use, and 4) Flavors. METHODS: Two message trials were conducted in U.S. Amazon Mechanical Turk workers aged 18-24 using a 2 (content: addiction, harm) × 3 (theme: alone, + flavors, + social) design with multiple messages in each of the six categories. Participants were assigned to view a random subset of messages and report on likeability and perceived message effectiveness (PME). Phase 1 (n = 200) tested 33 messages and 32 images. Phase 2 (n = 769) tested combinations of Phase 1's 24 most effective messages with 6 images rated most likeable or effective. Linear mixed effects models assessed the effect of content, theme, image, and their interactions on message response. RESULTS: In both trials, most participants were past 30-day tobacco users. Harm content messages produced higher PME ratings than addiction content messages, and flavor theme messages were correlated with higher likeability scores than "content alone" theme messages. In Phase 2, flavor and social message themes decreased the PME of harm messages. There was no effect of images on either outcome controlling for the independent or interaction effects of content, theme, and image. CONCLUSIONS: Messages conveying the harms of vaping may be best for reducing vaping in young adult tobacco users; flavor and social themes may diminish their effectiveness.