Changing Perceptions of Harm of e-Cigarette vs Cigarette Use Among Adults in 2 US National Surveys From 2012 to 2017

<h3>Importance</h3> Debate is ongoing about whether the scientific evidence of the health risks of electronic cigarettes (e-cigarettes) compared with combustible cigarettes (hereinafter referred to as cigarettes) has been accurately communicated to the public. Large representative surveys are needed to examine how the public perceives the health risk of e-cigarettes and how their perceptions change over time. <h3>Objective</h3> To examine how US adults perceived the harm of e-cigarettes relative to cigarettes and how their perception has changed from 2012 to 2017. <h3>Design, Setting, and Participants</h3> Survey study using data from 2 multiyear cross-sectional nationally representative surveys—the Tobacco Products and Risk Perceptions Surveys (TPRPS) and the Health Information National Trends Surveys (HINTS)—to assess perceived harm of e-cigarettes relative to cigarettes among US adults in 2012, 2014, 2015, 2016, and 2017. Respondents were selected via address-based sampling or random-digit dialing and consisted of adults 18 years or older. Analyses were conducted from February through April 2018. <h3>Main Outcomes and Measures</h3> Self-reported perceived harm of e-cigarettes relative to cigarettes. <h3>Results</h3> The analytical samples of TPRPS consisted of 2800 adults in 2012 (cumulative response rate, 7.3%), 5668 in 2014 (cumulative response rate, 6.6%), 5372 in 2015 (cumulative response rate, 6.8%), 5245 in 2016 (cumulative response rate, 6.4%), and 5357 in 2017 (cumulative response rate, 5.8%). The analytical samples of HINTS consisted of 2609 adults in 2012 (response rate, 39.9%), 3301 in 2014 (response rate, 34.4%), 2224 in 2015 (response rate, 33.0%), and 2683 in 2017 (response rate, 32.4%). The proportion of adults who perceived e-cigarettes as less harmful than cigarettes decreased from 39.4% (95% CI, 36.9%-41.9%) in 2012 to 33.9% (95% CI, 32.7%-35.2%) in 2017 in TPRPS and decreased from 50.7% (95% CI, 48.8%-52.7%) in 2012 to 34.5% (95% CI, 32.7%-36.3%) in 2017 in HINTS. During the same period, the proportion of adults who perceived e-cigarettes to be as harmful as cigarettes increased from 11.5% (95% CI, 10.0%-13.2%) in 2012 to 36.4% (95% CI, 35.1%-37.7%) in 2017 (TPRPS) and from 46.4% (95% CI, 44.5%-48.3%) in 2012 to 55.6% (95% CI, 53.7%-57.5%) in 2017 (HINTS). Those who perceived e-cigarettes to be more harmful than cigarettes increased from 1.3% (95% CI, 0.8%-2.2%) in 2012 to 4.3% (95% CI, 3.8%-4.9%) in 2017 (TPRPS) and from 2.8% (95% CI, 2.2%-3.5%) in 2012 to 9.9% (95% CI, 8.8%-11.1%) in 2017 (HINTS). <h3>Conclusions and Relevance</h3> In this study, the proportion of US adults who perceived e-cigarettes to be as harmful as or more harmful than cigarettes increased substantially from 2012 to 2017. The findings of this study underscore the urgent need to accurately communicate the risks of e-cigarettes to the public, which should clearly differentiate the absolute from the relative harms of e-cigarettes.