Changing Perceptions of Harm of E-Cigarettes Among U.S. Adults, 2012-2015.

Introduction: Although the impact of long-term use of electronic cigarettes (e-cigarettes) on health is still unknown, current scientific evidence indicates that e-cigarettes are less harmful than combustible cigarettes. The study examined whether perceived relative harm of e-cigarettes and perceived addictiveness have changed during 2012-2015 among U.S. adults.

Methods: Data were from Tobacco Products and Risk Perceptions surveys of probability samples representative of U.S. adults in 2012, 2014, and 2015. Changes over time in perceived harmfulness of e-cigarettes were examined using pairwise comparisons of proportions and multinomial logistic regression analysis. Analyses were conducted in January 2016.

Results: Whereas 11.5% and 1.3% of adults perceived e-cigarettes to have about the same level of harm and to be more harmful than cigarettes, respectively, in 2012, 35.7% and 4.1% did so in 2015. The proportion of adults who thought e-cigarettes were addictive more than doubled during 2012-2015 (32.0% in 2012 vs 67.6% in 2015). Compared with 2012, the odds of perceiving e-cigarettes to be equally or more harmful (than to be less harmful) doubled (95% CI=1.64, 2.41) in 2014, and tripled (95% CI=2.60, 3.81) in 2015.

Conclusions: There is an increase in the proportion of U.S. adults who misperceive the harm of e-cigarettes and consider them to be as harmful as combustible cigarettes. The study highlights the need to design public health messages that accurately interpret the scientific data on the potential harm of e-cigarettes and clearly differentiate the absolute from the relative harm of e-cigarettes.