Abstract
INTRODUCTION: The proportion of the population who believe e-cigarettes are equally or more harmful than cigarettes is increasing; however, less is known about why people have these perceptions. METHODS: In a 2022 survey of 2307 adults in the United States ages 18-45, we coded a subsample of open-ended responses (n = 461) asking participants who use cigarettes, e-cigarettes, or both products to explain their relative harm perceptions. We also asked all participants who believed that e-cigarettes are at least as harmful (n = 1576) close-ended survey questions assessing agreement with reasons for these perceptions. Questions also asked participants to select the top three reasons that most closely explained their beliefs. Chi-square tests evaluated differences by tobacco use status. RESULTS: In open-ended questions (n = 461), adults who believed e-cigarettes are equally or more harmful than cigarettes (59%) explained that e-cigarettes are: damaging to health (35%-37%), contain harmful chemicals (29%-33%), and still contain nicotine (18%-24%). Adults who believed that e-cigarettes are less harmful (41%) most frequently explained reasoning related to vapor being less harmful than smoke/combustion (30%-45%), fewer chemicals (34%-45%), and fewer or less severe health harms (24%-42%). In close-ended questions, beliefs about addiction and people using e-cigarettes more frequently elicited the highest agreement (82.8%-88.5%) and were commonly selected as "top 3" beliefs (41.6%-51.7%) among participants who believed e-cigarettes were as or more harmful than cigarettes. DISCUSSION: Beliefs underlying relative harm perceptions include beliefs about both health harms and addiction. Open-ended responses can inform more detailed close-ended survey items on specific reasons for relative harm perceptions. IMPLICATIONS: Numerous explanations contribute to how individuals perceive the relative harm of e-cigarettes compared to combustible cigarettes. This study extends beyond single-item assessments of harm perception by exploring not only what people believe but also why they hold these beliefs and provides important context to existing survey research that use a broad relative harm measure. Participants cited both reasons related to health harms and addiction to explain their harm perceptions. These insights suggest that commonly used survey items may capture beliefs about health harm, addiction, and frequency of use. Findings from this analysis can also inform the development of new items that more precisely measure the underlying rationale for relative harm perceptions of e-cigarettes versus combustible cigarettes.