Background: Electronic cigarettes (e-cigarettes) were introduced to the United States marketplace in 2007 and had dominated all other tobacco products used by youth by 2014. In May 2016, the Food and Drug Administration extended the final rule to include e-cigarettes in implementing text-based health warnings on cigarette packs and advertising, as required by the 2009 Tobacco Control Act. This study tested the hypothesis that youth's perceived harm of using e-cigarettes mediates the impact of seeing warning labels on their use intentions. Methods: We used a cross-sectional quantitative research design to analyze the 2019 National Youth Tobacco Survey data from 12,563 students in middle schools (grades 6 - 8) and high schools (grades 9 - 12) in the U.S. We conducted the 4-step Baron and Kenny Mediation Analysis using IBM SPSS® Hayes' PROCESS macro analysis. Results: Our study revealed a mediational process's presence, confirming the mediational role of youth's perceived harm of e-cigarettes on the relationship between seeing a warning label and their use intentions. Conclusion: This study provided insights into the relationship between seeing warning labels and the intention to use e-cigarettes among youth. Through the Tobacco Control Act, influential warning labels potentially increase youth's perception of harm in e-cigarettes, lowering their intention to use.
Keywords: Youth e-cigarette use intention; harm reduction; perceive harm; warning label.