An experimental study of messages communicating potential harms of electronic cigarettes.

There has been an upsurge of e-cigarette use in the United States in recent years. While e-cigarettes may contain lower levels of toxic chemicals than combusted cigarettes, they still pose serious health hazards, including increased risk for heart and respiratory disease. Despite these risks, public awareness of the health harms of e-cigarettes remains low. Thus, it is important to educate the public about the potential harms of e-cigarettes. This study took themes commonly found in antismoking messages and used them to develop messages about harms of e-cigarettes. A national sample of 2801 current smokers and nonsmokers (aged 18+ years) were randomized to view one of four e-cigarette messages (harmful effect of chemicals, uncertainty about ingredients, distrust of big tobacco, or cost of vaping) or a control message (bottled water ad). Participants' reactions to the messages and behavioral intentions were assessed immediately following the exposure. MANOVA examined effects of the messages on blocks of the outcome variables and univariate analyses estimated adjusted means for each experimental condition for each outcome. The message about harmful chemicals was perceived as the most informative and effective and elicited the highest levels of negative emotions (Ps<0.05). However, on measures of actual effectiveness, the other messages performed equally well. Specifically, messages with different themes (harmful chemicals, uncertainty about ingredients, anti-industry, or financial cost) increased perceived risk of e-cigarettes, support for e-cigarette control, and lowered self-exempting beliefs and intentions to use e-cigarettes (Ps<0.05). Themes commonly used in anti-smoking messages may be effective in educating the public about the potential harm of e-cigarettes. The observed differential effects of the messages suggest the need to use multiple themes in a public education campaign about e-cigarettes.