Relative Harm Perceptions of E-Cigarettes Versus Cigarettes, U.S. Adults, 2018-2020

Introduction: It is unknown how U.S. adults' relative harm perceptions of E-cigarettes versus cigarettes and associated behaviors changed during the E-cigarette or vaping product use‒associated lung injury epidemic (late 2019) and COVID-19 pandemic (since early 2020).

Methods: Data from cross-sectional nationally representative Health Information National Trends Survey collected in 2018 (n=3,360), 2019 (n=3,217), and 2020 (n=3,677) (analyzed in 2021) were used to estimate changes in relative harm perceptions of E-cigarettes versus cigarettes (less harmful, as harmful, more harmful, don't know as a measure of uncertainty). In addition, changes in exclusive cigarette smoking, exclusive E-cigarette use, and dual use were estimated for each relative harm perception level.

Results: Perceptions of E-cigarettes as more harmful than cigarettes doubled year on year, increasing most between 2019 and 2020 (2018: 6.8%, 2019: 12.8%, 2020: 28.3%), whereas uncertainty in relative harm declined (2018: 38.2%, 2019: 34.2%, 2020: 24.7%). Less harmful relative perceptions declined (2018:17.6%, 2019:15.3%, 2020:11.4%), whereas as harmful perceptions remained steady (2018: 37.4%, 2019: 37.7%, 2020: 35.6%). Exclusive cigarette smoking increased between 2019 and 2020 among those who perceived E-cigarettes as relatively more harmful (2018: 18.5%; 2019: 8.4%; 2020: 16.3%), exclusive E-cigarette use increased linearly among those who perceived them as relatively less harmful (7.9%, 15.3%, 26.7%), and dual use increased linearly in those who perceived them relatively as harmful (0.1%, 1.4%, 2.9%).

Conclusions: Perceptions of E-cigarettes as more harmful than cigarettes increased sharply between 2019 and 2020. Increases in tobacco product use were potentially guided by product-specific relative harm perceptions because changes occurred primarily in individuals who perceived their preferred product as relatively less harmful, suggesting the need for accurate messaging of relative and absolute product risks.