摘要：Objectives. We assessed the characteristics associated with the awareness, perceptions, and use of electronic nicotine delivery systems (e-cigarettes) among young adults. Methods. We collected data in 2010–2011 from a cohort of 2624 US Midwestern adults aged 20 to 28 years. We assessed awareness and use of e-cigarettes, perceptions of them as a smoking cessation aid, and beliefs about their harmfulness and addictiveness relative to cigarettes and estimated their associations with demographic characteristics, smoking status, and peer smoking. Results. Overall, 69.9% of respondents were aware of e-cigarettes, 7.0% had ever used e-cigarettes, and 1.2% had used e-cigarettes in the past 30 days. Men, current and former smokers, and participants who had at least 1 close friend who smoked were more likely to be aware of and to have used e-cigarettes. Among those who were aware of e-cigarettes, 44.5% agreed e-cigarettes can help people quit smoking, 52.8% agreed e-cigarettes are less harmful than cigarettes, and 26.3% agreed e-cigarettes are less addictive than cigarettes. Conclusions. Health communication interventions to provide correct information about e-cigarettes and regulation of e-cigarette marketing may be effective in reducing young adults’ experimentation with e-cigarettes. Electronic nicotine delivery systems (commonly known as electronic cigarettes or e-cigarettes) are battery-operated vaporizing devices in the shape of a cigarette that deliver nicotine vapor to users. Although the product has been marketed as a safe alternative to cigarettes because it contains only nicotine and not the other harmful ingredients found in cigarettes, 1 the US Food and Drug Administration 2 showed that some tested samples of e-cigarettes also contained toxic substances such as tobacco-specific nitrosamines, and 1 contained diethylene glycol. Public health professionals are also concerned that e-cigarettes may impede the reduction in prevalence of smoking in the United States for 3 reasons. 1,3–5 First, the product may weaken the effect of clean indoor air policies on smokers because smokers can use e-cigarettes as bridging products indoors, which may lessen their motivation to quit smoking. Second, smokers may use e-cigarettes instead of proven-effective smoking cessation treatments when trying to quit smoking even though the e-cigarettes’ effectiveness as quit aids is still largely unknown. Third, e-cigarettes may be gateways to cigarette smoking. Nonsmokers may experiment with e-cigarettes (especially when these products are flavored), develop nicotine addiction, and subsequently switch to smoking cigarettes. Examining the awareness, perceptions, and use of e-cigarettes among young adults is important because they may still be in the stage of initiating tobacco use. 6 Furthermore, young adults are in general more likely to try new things. 7 They may therefore pay more attention to new products such as e-cigarettes and be more likely to try e-cigarettes. This hypothesis is partially supported by findings from a national survey of US adults in 2010 showing that young adults (aged 18–24 years) were most likely to have heard of e-cigarettes (41.0%, vs 32.2% among all adults). 8 Young adults also have a higher prevalence of tobacco use than any other age group, with 1 in 3 young adults smoking. 6 E-cigarettes may delay young adults from quitting smoking, making it even harder to reduce a nearly static trend in young adult tobacco use. However, little is known about the characteristics associated with awareness and use of e-cigarettes among young adults. Investigators of the previous national survey did not examine the characteristics of awareness and use of e-cigarettes specific to this age group. 8 Young adults’ perceptions of e-cigarettes are largely unknown. We identified only 1 study that assessed the perceptions of e-cigarettes among an international sample of e-cigarette users recruited through the Internet, 9 which reported that 83.5% of users believed e-cigarettes are less toxic than tobacco and 76.8% used e-cigarettes to quit smoking or avoid relapse. However, the investigators did not report the prevalence of these perceptions specific to young adults and did not assess the characteristics associated with these perceptions. In this study, we assessed the characteristics associated with awareness and use of e-cigarettes among young adults, using data from a population-based cohort study. We also assessed the characteristics associated with selected perceptions of e-cigarettes (potential to aid smoking cessation and harmfulness and addictiveness relative to cigarettes), as well as the associations between these perceptions and use of e-cigarettes.
