Considerations and Future Research Directions for E-Cigarette Warnings-Findings from Expert Interviews.

Tobacco warning labels are important sources of risk information but research historically has been cigarette-centric. This qualitative study aimed to inform future direction and research on warnings for e-cigarettes. Between June and August 2016, we conducted interviews with 10 researchers with expertise in tobacco warning label research. Interviewees were registrants of a 2016 National Cancer Institute grantee meeting on tobacco warnings. Several participants agreed that the Food and Drug Administration's new nicotine addiction warning for e-cigarettes could be informative but that it might not resonate with young people. Many agreed that more than one warning would be important as e-cigarette science evolves and that research on additional warning themes (e.g., nicotine exposure, harmful constituents) and execution styles (including use of pictorials) was important. Participants were somewhat mixed about the use of reduced-risk messages within e-cigarette warnings, but agreed that research on how to communicate about cigarette/e-cigarette relative risks was needed. Overall, more research is needed on tobacco warnings for non-cigarette products, including on the message content, placement, execution and potential impact on audiences' product knowledge, risk perceptions and use intentions. This is particularly needed for products such as e-cigarettes which may have harm-reduction potential relative to cigarettes and require unique considerations.