Journal of Adolescent Health 49 (2011) 542–546 www.jahonline.org Original article Electronic-Cigarette Smoking Experience Among Adolescents Jun Ho Cho, Ph.D., M.P.H., Eunyoung Shin, Ph.D., M.P.H., and Sang-Sik Moon, Ph.D., M.P.H.* Department of Health Administration, Hanyang Women’s University, Seoul, Republic of Korea Article history: Received December 16, 2010; Accepted August 2, 2011 Keywords: Electronic cigarette; Adolescents; Awareness rates; Contact routes; Internet A B S T R A C T Objectives: To investigate the level of awareness and contact routes to electronic cigarette (e-cigarette), and to identify significant factors that may affect adolescent use of e-cigarettes; this study explores the experience of e-cigarettes among adolescents. Methods: Using the data from the 2008 Health Promotion Fund Project in Korea, we used a hierarchical logistic regression analysis to evaluate gender, level of school, family smoking, perception of peer influence, satisfaction in school life, and cigarette smoking experience as predictors of trying e-cigarettes among adolescents in five schools in Korea. Results: Overall, 444 (10.2%) students responded as having seen or heard of e-cigarettes. Twenty-two (.5%) students reported as having used an e-cigarette. The contact routes of information on e-cigarettes were the Internet (249, 46.4%), friends (150, 27.9%), television (59, 11.0%), books (50, 9.3%), and others (29, 5.4%). The following factors were determined to be statistically significant predictors of e-cigarette experience: male gender, perception of peer influence, satisfaction in school life, and cigarette smoking experience. Conclusions: In light of this fact, continuous attention needs to be paid on the marketing of e-cigarettes on Internet sites to prevent adolescents from being exposed to unsupported claims about e-cigarettes and to provide appropriate information on health effects. 䉷 2011 Society for Adolescent Health and Medicine. All rights reserved. Smoking is a major cause of adverse health effects in most countries. In the United States alone, an estimated 443,000 people die prematurely from smoking or from exposure to secondhand smoke each year, and another 8.6 million have a serious illness caused by smoking [1]. Especially, adolescent smoking is clinically important. In earlier study, adolescent smoking was associated with mental health symptoms and substance use disorders. Therefore, information on adolescent tobacco use may assist in identifying patients at risk for substance abuse and mental problems [2]. To prevent the diseases and deaths caused by cigarette use, the researchers have suggested various tobacco replacements as alternatives to cigarettes, such as smokeless * Address correspondence to: Sang-Sik Moon, Ph.D., M.P.H., Department of Health Administration, Hanyang Women’s University, 17 Haengdang-dong Seongdong-gu, Seoul 133–793, Republic of Korea. E-mail address: mssok1@naver.com (S.S. Moon). The comments of this article are solely the responsibility of the authors and do not necessarily represent the official view of the Ministry of Health and Welfare in Korea. tobacco (ST) and nicotine delivery systems. Electronic cigarette (e-cigarette) is one popular type of electronic nicotine delivery system (ENDS), a battery-powered device that looks like a cigarette but does not involve smoke and which enables users to inhale vaporized nicotine (WHO, 2009) [3]. With respect to e-cigarettes, there is growing interest as well as concern among cigarette smokers, manufacturers, health professionals, and policy managers. The World Health Organization has urged marketers of e-cigarettes to halt their unproved claims about the therapeutic benefits of using e-cigarettes and has indicated that there is no reliable scientific evidence to confirm the product’s safety and efficacy [4]. As of 2009, there are some countries, including New Zealand, the United Kingdom, and members of the European Union, that allow marketing of ecigarettes within their current regulatory framework, whereas there are other countries, including Australia, Brazil, China, Singapore, Thailand, and Uruguay, that have completely banned the sale and marketing of ENDS [3]. In the United States, the New York State Assembly prohibits the sale of e-cigarettes to minors, and also of items that are not defined as tobacco products or 1054-139X/$ - see front matter 䉷 2011 Society for Adolescent Health and Medicine. All rights reserved. doi:10.1016/j.jadohealth.2011.08.001 J.H. Cho et al. / Journal of Adolescent Health 49 (2011) 542–546 approved by the Food and Drug Administration for tobacco use cessation or harm reduction [5]. Conversely, beginning in 2007, marketers in the Republic of Korea began to sell e-cigarettes to the public, which includes adolescents, through various Internet sites. However, in November 2008, the Ministry of Strategy and Finance made an authoritative interpretation that regarded ecigarettes as a type of cigarette, and therefore only allowed marketing within the existing regulatory framework for tobacco [6]. After that judgment was made, the marketing of e-cigarettes through the Internet was banned. In 2009, the United States Food and Drug Association reported that tobacco-specific nitrosamines (TSNAs) and tobacco-specific impurities, such as diethylene glycol, were detected in two e-cigarette products, albeit at very low levels [7]. TSNAs are known to be carcinogenic [8]. Despite the fact that e-cigarette use is now a worldwide phenomenon, very little is known regarding its use within the adolescent community [9,10]. This study was conducted to assess the level of awareness and contact routes to e-cigarette among adolescents, and to test the following specific hypotheses: Variables, such as male gender, older age, smoking in the family, perception of peer influence, dissatisfaction with school life, and previous experience with cigarette smoking, increase the likelihood of trying e-cigarettes for the first time. Methods Data were collected during the course of a 2008 project titled “Primary study for appropriate policies to regulate smokeless tobacco products in Korea” financed by the Health Promotion Fund of the Ministry of Health and Welfare in Korea [11]. Data were collected on sociodemographic characteristics (age, gender, level of school [middle and high school, university], residential district), current cigarette use, ST use, e-cigarette use, cigarette availability, knowledge and behavior with regard to tobacco products, family smoking history, perception of peer influence, attempts to quit smoking, and school life (satisfaction and their school record). Of these, only the data pertaining to e-cigarette use among adolescents were used to test the study hypotheses. The survey adopted a cluster probability sample design. First, to distribute the districts evenly, following five schools were chosen based on their geographic locations: one school was selected from southern Seoul area, two from northern Seoul area, one from near Seoul area (the Satellite Cities of the Seoul Metropolitan), and one from a province of the country. Second, within each selected school, most of the classrooms were sampled, and students in those classrooms were invited to participate in the survey. Instead of names, identification codes were used to ensure confidentiality. All survey instruments used for data collection were reviewed and approved by the Institutional Review Board of the Hanyang Women’s University. Measures E-cigarette questions. For assessing the level of awareness and contact routes among the test subjects regarding e-cigarettes, the students were asked, “Have you ever seen or heard of e-cigarettes?” If students answered in the negative, they were classified into the “No” category. If they answered in the affirmative, they were classified into the “Yes” category, and their contact sources, such as friends, television, books (including journals), Internet, and others, were recorded. With respect to e-cigarette use, students were 543 asked, “Have you ever smoked an e-cigarette, even one or two puffs?” If they answered in the affirmative, they were classified as having had the experience of e-cigarette use. Other variables. With respect to family smoking, students were asked, “Do you have smoking persons among family members?” If they answered none, they were classified into the “No” category, whereas if they answered one or more of the following options: father, mother, grandfather, grandmother, brother, sister, or others, they were classified into the “Yes” category. With respect to perception of peer influence, students were asked, “Do you think your smoking behaviors are easily affected by friends?” Response options were as follows: definitely yes, probably yes, probably not, and definitely not. The definitely yes and probably yes responses were merged into the “Yes” category, and the probably not and definitely not were merged into the “No” category. With respect to satisfaction in school life, students were asked, “Are you satisfied with school life?” Response options were as follows: definitely yes, probably yes, indifferent, probably not, and definitely not. The definitely yes and probably yes responses were merged into the “Satisfaction” category, the indifferent responses were classified into the “Indifferent” category, and probably not and definitely not responses were merged into the “Dissatisfaction” category. With respect to traditional cigarettes’ experience, students were asked, “Have you ever smoked a cigarette, even one or two puffs?” If they answered in the affirmative, they were classified into “Ever” category, as having had the experience of traditional cigarette use. Statistical analysis Frequency analyses were conducted to assess the rates of e-cigarette awareness and experience, and to classify contact routes of information on e-cigarette use among adolescents. In addition, to assess the predictors of e-cigarette smoking, we performed 2 and multiple hierarchical logistic regression analyses for e-cigarette experience by gender, level of school, cigarette smoking family, perception of peer influence, satisfaction in school life, and cigarette smoking experience. Additionally, Fisher exact test was applied to compensate 2 analyses if the expected values in contingency table were small. SPSS software package (version 12.0; SPSS Institute, Inc, Cary, NC) was used for the statistical analyses. Results A total of 4,341 students (70.5% participation) responded to the questionnaire. Two thousand three hundred sixty-nine middle school students and 1,874 high school students from five schools participated in the survey; 1,988 of them were boys and 2,245 of them were girls. The mean age of students in middle schools was 14.0 years (standard deviation: .87) and that of students in high schools was 16.5 years (standard deviation: .77). Overall, 444 (10.2%) students responded as having seen or heard of e-cigarettes. Twenty-two (.5%) students reported as having used an e-cigarette. The frequencies and percentages were determined by contact routes of information on ecigarettes among adolescents in multiple response approach. The highest contact route of information on e-cigarettes was the Internet (249, 46.4%). The second highest contact route was friends (150, 27.9%), followed by television (59, 11.0%), books 544 J.H. Cho et al. / Journal of Adolescent Health 49 (2011) 542–546 Table 1 Results of 2 analyses of electronic-cigarette experience among adolescents in five schools in Korea Independent variables Students number (%) Gender Girls (n ⫽ 2,221) Boys (n ⫽ 1985) Level of school Middle school (n ⫽ 2,341) High school (n ⫽ 1,857) Cigarette smoking family No (n ⫽ 1,845) Yes (n ⫽ 2,363) Propensity to be easily affected by friends Yes (n ⫽ 1,605) No (n ⫽ 2,442) School life Satisfaction (n ⫽ 1,876) Indifference (n ⫽ 1,664) Dissatisfaction (n ⫽ 685) Cigarette smoking experience Never (n ⫽ 3,402) Ever (n ⫽ 810) 2 p (significantly) 10.64 .001* 4 (.18) 18 (.91) .90 .343 10 (.43) 12 (.65) 5.27 .022** 2.65 .104 4 (.22) 17 (.72) 5 (.31) 17 (.70) 10.90 .004*** 44.08 .000* 9 (.48) 4 (.24) 9 (1.31) 5 (.15) 16 (2.0) * p ⬍ .001. ** p ⬍ .05. *** p ⬍ .01. (50, 9.3%), and others (29, 5.4%). Other routes included teachers, athletes, fathers, mothers, and newspapers. Through 2 analyses, the differences in e-cigarette experience among adolescents are shown in Table 1. Fisher exact test was applied to compensate 2 analyses when the values in contingency table were less than five. Statistically significantly higher rates of e-cigarette experience were found for adolescent boys, for those having cigarette smoking in their families, for those with lower satisfaction in school life, and for those who had previously smoked. Contrary to expectations, however, statistically significant associations were not found for school level (middle vs. high school) and for the perception of peer influence. Results from the multiple hierarchical logistic regression analyses are indicated in Table 2. Model 1, which included demographic variables, such as gender and level of school as predictors of e-cigarette use, produced a good fit to the data according to the Hosmer–Lemeshow 2 test (22 ⫽ .7; p ⫽ .7). A statistically significant difference was found between adolescent boys and girls (p ⬍ .01). Adolescent boys were 6.3 times more likely than female students to use e-cigarettes. Thus, the data support part of the hypothesis, with the rates of e-cigarette use being higher among male students. Model 2, which also includes cigarette smoking in the family and the perception of peer influence as predictors of e-cigarette use, produced a good fit to the data according to the Hosmer– Lemeshow 2 test (26 ⫽ 5.7; p ⫽ .5). Same as in model 1, adolescent boys were 6.4 times more likely than female students to use e-cigarettes. Accordingly, students in middle schools were more likely to use e-cigarettes than those in high schools, although there remained no significant difference (p ⫽ .123). Statistically significant differences were found for cigarette smoking in the family—the students who had smoking persons among family members were 3.4 times more likely to use e-cigarettes than those who did not have smoking persons (5 ⬍ .05). As for perception of peer influence, interestingly, the students who perceived to be not easily influenced by their friends were 3.0 times more likely (5 ⬍ .05) to use e-cigarettes than those who perceived to be easily affected by their friends. In model 3, we added satisfaction in school life to model 2 as one of the predictors of e-cigarette use. Model 3 produced a good Table 2 Results of multiple logistic regression analyses of dependent variables with electronic-cigarette experience among adolescents Independent variables Model 1a OR (95% CI) Gender Girls 1.0 Boys 6.3* (2.0–20.6) Level of school Middle school 1.0 High school .7 (.3–1.6) Cigarette smoking family No Yes Propensity to be easily affected by friends Yes No School life Satisfaction Indifference Dissatisfaction Cigarette smoking experience Never Ever Sample size was n ⫽ 4,173. CI ⫽ confidence interval; OR ⫽ odds ratio. a Model significant at p ⬍ .05. * p ⬍ .01. ** p ⬍ .05. *** p ⬍ .001. Model 2a OR (95% CI) Model 3a OR (95% CI) Model 4a OR (95% CI) 1.0 1.0 1.0 6.4* (1.9–20.9) 5.8* (1.8–19.1) 3.5** (1.0–11.8) 1.0 1.0 .6 (.2–1.4) 1.0 .6 (.2–1.4) .5 (.2–1.2) 1.0 1.0 1.0 3.4** (1.1–10.0) 3.4** (1.1–10.1) 2.8 (.9–8.5) 1.0 3.0** (1.0–9.0) 1.0 2.9 (.99–8.8) 1.0 3.9** (1.3–12.0) 1.0 1.0 .6 (.2–1.9) 2.8** (1.1–7.3) .4 (.1–1.4) 1.9 (.7–5.0) 1.0 11.2*** (3.9–32.3) J.H. Cho et al. / Journal of Adolescent Health 49 (2011) 542–546 fit to the data according to the Hosmer–Lemeshow 2 test (28 ⫽ 7.8; p ⫽ .5). After we added satisfaction in school life, variables, such as gender, level of school, and cigarette smoking in the family, continued to be similar to the ORs and significance levels observed in model 2, except for perception of peer influence. More specifically, model 3 showed that boys were 5.8 times more likely than girls to use e-cigarettes (p ⬍ .01), and students who had smoking persons among family members were 3.4 times more likely to use e-cigarettes than those who had no smoking persons (p ⬍ .05). Consistent with models 1 and 2, there was no significant difference in e-cigarette use when comparing middle school students with high school students (p ⫽ .207). However, there was no statistically significant difference in e-cigarette use when comparing students who perceived to be not easily affected by friends with those who perceived to be easily affected by friends (p ⫽ .053). With respect to satisfaction in school life, students who were dissatisfied with their school life were 2.8 times more likely (p ⬍ .05) to use e-cigarettes than those who were satisfied with their school life. With cigarette smoking experience, model 4 included all the predictive variables. Model 4 produced a good fit to the data according to the Hosmer–Lemeshow 2 test (27 ⫽ 12.7; p ⫽ .120). After controlling for cigarette smoking experience, boys were 3.5 times more likely than girls to use e-cigarettes (p ⬍ .05), and the students who perceived to be not easily affected by friends were 3.9 times more likely to use e-cigarettes than those who perceived to be easily affected by friends (p ⫽ .016), although the difference was not significant in the previous model 3. In addition, students with experience in cigarette smoking were 10.8 times more likely to use e-cigarettes than those with no experience in using e-cigarettes (p ⬍ .001). However, previously significant differences in e-cigarette use based on cigarette smoking in the family were not significant in this model (p ⫽ .074). Thus, most of the hypotheses were supported by these data, with the exception of the perception of peer influence as a predictive factor for e-cigarette use. Discussion The results of this study suggest that e-cigarette advertisements and related promotion activities are spreading to adolescents, and internationally through the Internet [3]. Within a couple of years after companies began to market e-cigarettes, the awareness rate among adolescents participating in this survey was 11%. This result provides statistical evidence for the opinion that market penetration of unregulated ENDS has expanded rapidly to most World Health Organization regions [3]. However, an issue of concern is that the information provided by the sellers to adolescents do not contain risk-related data, despite the fact that carcinogenic-ingredients, such as TSNAs, were detected in e-cigarette products [7,8]. The results also indicate that gender, propensity to be affected by friends, satisfaction in school life, and previous experience with cigarette smoking may be predictors of e-cigarette use. After controlling for the variables described, it was possible to assess the relationship between e-cigarette use and the variables. Specifically, in the final model (model 4), it was found that boys (compared with girls), propensity to not be affected by friends, dissatisfaction in school life, and previous cigarette smoking experience are important predictors of e-cigarette use. The variable of school level remained as an insignificant factor, and the variables of cigarette smoking in the family and dissat- 545 isfaction of school life changed from being a significant to a nonsignificant predictor when adding cigarette smoking experience to the statistical model. According to earlier reports, the prevalence rates of tobacco product use, such as cigarette, ST, and water pipe cigarette, among older students and students with smoking persons in their families were higher than among the younger students and those without smoking persons in their families [12]. In detail, when earlier researchers examined male ST users by grade, they reported 7% of 5th graders, 22% of 8th graders, and 32% of 11th graders to be ST users [13]. Also, 4% of middle school students and 11% of high school students reported ever having used a water pipe cigarette, and 3.6% of middle school students and 9.9% of high school students reported as current cigarette users [14]. In the case of cigarettes, ST, and water pipe cigarettes, adolescent smoking behaviors were known to be largely affected by friends [15,16]. The current study results indicated that prevalence rates of e-cigarette use among students who perceived to be not easily affected by friends were higher than those who perceived to be easily affected by friends. However, this result has limitation when considering the perception of peer influence to be the peer pressure. The type of question, such as asking adolescents whether they think their smoking behaviors are easily affected by friends, is likely to generate response bias because of social desirability. Thus, the peer pressure related to e-cigarette use among adolescents needs to be assessed in a future project. This study indicates that continuous attention needs to be paid on the marketing of e-cigarettes on Internet sites to prevent adolescents from being exposed to unsupported claims about e-cigarettes. The students taking part in the survey would mainly obtain information on e-cigarettes through the Internet. Additionally, the adolescents could purchase e-cigarettes through the Internet during the period of the survey. The sale of e-cigarettes on Internet sites was banned later, in November 2008. It is noted, however, that according to a previous report, only 25.5% of the Internet sites sampled prohibited purchases by minors, although it was illegal for minors to buy cigars [17]. This study did not investigate whether adolescents were currently using e-cigarettes on a periodic basis, but rather assessed whether they had ever used an e-cigarette. Further research needs to assess the rates of current use of e-cigarettes among adolescents. Also, because the study was cross-sectional, it could not establish the direction of the association between the various predictive variables and e-cigarette use among adolescents. Accordingly, further research indicating the direction of the associations should be performed. Moreover, although large numbers of students participated in this study, the prevalence rates of e-cigarette use were determined relatively low among adolescents. The most likely explanations are that e-cigarette use is still in its infancy and, as in other countries, current numbers of e-cigarette users are very small in Korea. Therefore, this point may be acceptable. Furthermore, the health risks because of e-cigarette use need to be assessed in a future project, in terms of both acute and chronic affects, including nicotine addiction. To our knowledge, no population-based studies have estimated the awareness and experience of e-cigarette among adolescents. Therefore, the results of this study may provide useful evidence for adolescent behaviors on e-cigarette use. 546 J.H. Cho et al. / Journal of Adolescent Health 49 (2011) 542–546 Acknowledgments The authors thank Nam Won Paik, Professor of Seoul National University in Korea, for the thoughtful comments on the article, and Dr. Samuel Y. Paik, Senior Specialist of Abbott Laboratories in the United States, for his highly valuable reviewing and editing. This study was funded by the 2008 Health Promotion Fund of Ministry of Health and Welfare in Korea, and additional support was provided by the Hanyang Women’s University. References [1] Tobacco Use: Targeting the Nation’s Leading Killer. At a glance 2010, National center for chronic disease prevention and health promotion improving health and quality of life for all people. Department of Health and Human Services, Center for Disease Control and Prevention, 2010. Available at: http://www.cdc.gov/chronicdisease/resources/publications/aag/osh. htm. Accessed August 6 2010. [2] Chang G, Sherritt L, Knight JR. 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