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E-Cigarette Marketing Exposure Is Associated With E-Cigarette Use Among US Youth

      Abstract

      Purpose

      E-cigarettes are currently the most commonly used tobacco product among US youth. However, unlike conventional cigarettes, e-cigarettes are not subject to marketing restrictions. This study investigates the association between exposure to e-cigarette marketing and susceptibility and use of e-cigarettes in youth.

      Methods

      Data were obtained from the 2014 National Youth Tobacco Survey. Participants were 22,007 US middle and high school students. Multivariate logistic regression models assessed the relationship between e-cigarette marketing (internet, print, retail, and TV/movies) and current and ever use as well as susceptibility to use e-cigarettes among never e-cigarette users.

      Results

      Exposure to each type of e-cigarette marketing was significantly associated with increased likelihood of ever and current use of e-cigarettes among middle and high school students. Exposure was also associated with susceptibility to use of e-cigarettes among current nonusers. In multivariate models, as the number of channels of e-cigarette marketing exposure increased, the likelihood of use and susceptibility also increased.

      Conclusions

      Findings highlight the significant associations between e-cigarette marketing and e-cigarette use among youth and the need for longitudinal research on these relationships.

      Keywords

      Implications and Contribution
      This study reveals an association between adolescent e-cigarette use and e-cigarette marketing exposure. Further revealed is an association between adolescent e-cigarette use susceptibility and exposure to e-cigarette marketing. Furthermore, each channel of advertising examined in this study is individually associated with a statistically significant increase in e-cigarette use and susceptibility.
      Electronic cigarettes (e-cigarettes) are the most commonly used nicotine product among adolescents, outpacing conventional cigarettes [
      • Arrazola R.
      • Singh T.
      • Caraballo R.
      • et al.
      Tobacco use among middle and high school students – United States, 2011-2014.
      ]. E-cigarette use among high school students increased from 1.5% in 2011 to 13.4% in 2014 [
      • Arrazola R.
      • Singh T.
      • Caraballo R.
      • et al.
      Tobacco use among middle and high school students – United States, 2011-2014.
      ]. From 2013 to 2014, e-cigarette use tripled among middle school (1.1%–3.9%) and high school (4.5%–13.4%) students [
      • Arrazola R.
      • Singh T.
      • Caraballo R.
      • et al.
      Tobacco use among middle and high school students – United States, 2011-2014.
      ]. Although research is limited on the short- and long-term health consequences of e-cigarette use, exposure to nicotine and e-cigarette aerosols present several public health concerns. Preliminary studies have detected the presence of harmful chemicals [
      • Cheng T.
      Chemical evaluation of electronic cigarettes.
      ] and carcinogens [
      • Kosmider L.
      • Sobczak A.
      • Goniewicz M.
      • et al.
      Carbonyl compounds in electronic cigarette vapors: Effects of nicotine solvent and battery output voltage.
      ] in e-cigarette liquids and aerosols. Studies show that exposure to nicotine during adolescence negatively influences adolescent brain development [
      U.S. Department of Health and Human Services
      The health consequences of smoking-50 years of progress: A report of the Surgeon General.
      ] and is associated with attention and cognition deficits [
      • Galván A.
      • Schonberg T.
      • Mumford J.
      • et al.
      Greater risk sensitivity of dorsolateral prefrontal cortex in young smokers than in nonsmokers.
      ,
      • Treur J.
      • Willemsen G.
      • Vink J.
      • et al.
      Smoking during adolescence as a risk factor for attention problems.
      ], mood dysfunctions [
      • Moylan S.
      • Jacka F.
      • Pasco J.
      • Berk M.
      Cigarette smoking, nicotine dependence and anxiety disorders: A systematic review of population-based, epidemiological studies.
      ], and increased propensity for risk taking [
      • Cavalca E.
      • Kong G.
      • Krishnan-Sarin S.
      • et al.
      A preliminary experimental investigation of peer influence on risk-taking among adolescent smokers and non-smokers.
      ]. Indirectly, studies have shown a link between e-cigarette use and use of combustible tobacco products, such as conventional cigarettes [
      • Anand V.
      • McGinty K.L.
      • O'Brien K.
      • et al.
      E-cigarette use and beliefs among urban public high school students in North Carolina.
      ]. Furthermore, research suggests a temporal relationship, indicating use of e-cigarettes may act as the impetus for combustible tobacco use [
      • Bunnell R.
      • Agaku I.
      • King B.
      • et al.
      Intentions to smoke cigarettes among never-smoking US middle and high school electronic cigarette users: National Youth Tobacco Survey, 2011–2013.
      ].
      There is limited research on the impact of marketing on the use of e-cigarettes. However, tobacco advertising and point-of-sale marketing have been shown to cause tobacco use among youth and young adults [
      U.S. Department of Health and Human Services
      Preventing tobacco use among youth and young adults: A report of the Surgeon General.
      ] and increase positive perceptions of tobacco use among nonusers [
      • Biener L.
      • Siegel M.
      Tobacco marketing and adolescent Smoking: More support for a causal inference.
      ]. A study of adolescents who had never used e-cigarettes found a positive relationship between exposure to e-cigarette advertising and intentions to use e-cigarettes [
      • Farrelly M.
      • Duke J.
      • Porter L.
      • et al.
      A randomized trial of the effect of e-cigarette TV advertisements on intentions to use e-cigarettes.
      ]. Another study, using data from 2011, found an association between tobacco marketing and other protobacco influences (e.g., seeing products used on TV/movie) and use of e-cigarettes among adolescents [
      • Agaku I.
      • Ayo-Yusuf O.
      The effect of exposure to pro-tobacco advertising on experimentation with emerging tobacco products among U.S. adolescents.
      ]. However, the prevalence of e-cigarette experimentation among the adolescents in the sample was relatively low (3.1%) and current use was not assessed. Rapid changes in industry marketing [
      • Kim A.E.
      • Arnold K.Y.
      • Makarenko O.
      E-cigarette advertising expenditures in the U.S., 2011-2012.
      ], product awareness [
      • Farrelly M.
      • Duke J.
      • Porter L.
      • et al.
      A randomized trial of the effect of e-cigarette TV advertisements on intentions to use e-cigarettes.
      ], and use by adolescents [
      • Arrazola R.
      • Singh T.
      • Caraballo R.
      • et al.
      Tobacco use among middle and high school students – United States, 2011-2014.
      ] warrant ongoing research. It is vital to understand the relationship between marketing and e-cigarette use and susceptibility to use among adolescents, particularly as significant regulatory gaps remain as compared to conventional tobacco products. The Food and Drug Administration does not currently regulate the marketing or distribution of electronic cigarettes [
      • Baher R.Z.
      • Hua M.
      • Talbot P.
      Puffing topography and nicotine intake of electronic cigarette use.
      ], and state laws have not kept up with the market changes. This lack of regulation has allowed this industry to launch marketing campaigns that appeal particularly to adolescents.
      The United Kingdom is, currently, the only country in the world with comprehensive e-cigarette regulations, including restrictions on marketing [
      Institute for Global Tobacco Control
      Country laws regulating e-cigarettes: A policy scan.
      ]. Marketing restrictions to protect youth include banning advertisements likely to appeal to minors and those using people appearing to be under age 25 years to sell e-cigarettes. In addition, mediums with an adolescent audience of more than 25% cannot be used to advertise e-cigarettes, and e-cigarette advertisements cannot run adjacent to programs likely to appeal to adolescents. Many countries including Uruguay, Brazil, and Mexico have banned e-cigarettes entirely [
      • Grana R.
      • Benowitz N.
      • Glantz S.A.
      Background paper on E-cigarettes (electronic nicotine delivery systems).
      ].
      From 2011 to 2013, e-cigarette marketing expenditures increased nearly 10-fold, from $6.4 million to more than $60 million [
      • Kim A.E.
      • Arnold K.Y.
      • Makarenko O.
      E-cigarette advertising expenditures in the U.S., 2011-2012.
      ,
      • Sebastian M.
      E-cig marketing budgets growing by more than 100% year over year.
      ] in the United States. These figures account for print, television, radio, and digital advertising. Over this same period, there has been a corresponding growth in initiation, current use, and product awareness of e-cigarettes among youth [
      • Arrazola R.
      • Singh T.
      • Caraballo R.
      • et al.
      Tobacco use among middle and high school students – United States, 2011-2014.
      ]. This is not surprising, given prior experience with cigarette advertising and cigarette use among young people.
      The 2012 Report of the Surgeon General on Preventing Tobacco Use Among Youth and Young Adults documents the causal relationship between advertising and promotion for cigarettes and initiation of cigarette smoking among young populations. Recent reports document that e-cigarette marketing reaches the vast majority of young populations. The Centers for Disease Control and Prevention estimated that almost seven in 10 middle school and high school students are reached by e-cigarette marketing [
      • Singh T.
      • Marynak K.
      • Arrazola R.A.
      • et al.
      Vital signs: Exposure to electronic cigarette advertising among middle school and high school students – United States, 2014.
      ] and the truth initiative found that 84% of young people ages 13–21 years are aware of e-cigarette advertising [
      Truth Initiative
      Vaporized: Youth and young adult exposure to e-cigarette marketing.
      ]. However, it is still unknown whether consistent associations exist between exposure to e-cigarette marketing and susceptibility to and use of e-cigarettes among youth.

      Study aims and hypothesis

      This study aims to determine the association between exposure to e-cigarette marketing through several channels (internet, print, retail, and TV/movies) and e-cigarette use and susceptibility to use in a nationally representative sample of middle school and high school students. We hypothesize that exposure to e-cigarette marketing will be positively associated with ever use, current use, and susceptibility to e-cigarette use among young people. We further hypothesize that the magnitude of the relationship will increase with each additional marketing channel to which a young person is exposed. This study is the first to examine exposure to e-cigarette marketing, specifically, and its relationship to e-cigarette use and susceptibility to use e-cigarettes among youth in a nationally representative sample.

      Methods

      Study sample and population

      Data were obtained from the 2014 National Youth Tobacco Survey; a stratified, three-stage cluster sample design to produce a nationally representative sample of middle school and high school students in the United States. These data were collected from 207 schools with a sample size of 22,007.

      Procedure

      National Youth Tobacco Survey sampling procedures are probabilistic and conducted without replacement at all stages and entail selection of primary sampling units within each stratum, schools within each selected primary sampling unit, and classes within each selected school. Participation by schools and students are voluntary and student responses remain anonymous. The procedure is described in detail elsewhere [
      National Youth Tobacco Survey (NYTS)
      Centers for Disease Control and Prevention Web site.
      ].
      The university's committee for the protection of human subjects determined that the present study was exempt from institutional review board review.

      Measures

      E-cigarette use

      Ever use of e-cigarettes (experimentation) and use in the past 30 days (current use) were outcome variables in the analysis. Ever use of e-cigarettes was assessed by the questions “Have you ever tried an electronic cigarette or e-cigarette such as Blu, 21st Century Smoke or NJOY?” Those that responded “yes” (coded as 1) were considered to have had experimented with e-cigarettes; everyone else were considered a nonuser (coded as 0). Current use status of e-cigarettes was assessed by “During the past 30 days, on how many days did you use electronic cigarettes or e-cigarettes such as Blu, 21st Century Smoke or NJOY?” with those responding with anything other than “0” considered to be a current user of e-cigarettes (coded as 1).

      Susceptibility to e-cigarette use

      This measure used three items, similar to cigarette susceptibility criteria established by Pierce et al. [
      • Pierce J.P.
      • Choi W.S.
      • Gilpin E.A.
      • et al.
      Validation of susceptibility as a predictor of which adolescents take up smoking in the United States.
      ] and was coded as a binary variable (susceptible = 1/not susceptible = 0). Questions used to measure susceptibility among students who reported they had never used an e-cigarette were: “Do you think you will try an electronic cigarette or e-cigarette soon?”, “Have you ever been curious about using an electronic cigarette or e-cigarette such as Blu, 21st Century Smoke, or NJOY?” and “If one of your best friends were to offer you an electronic cigarette or e-cigarette, would you use it?” Responses for these questions included “definitely yes,” “probably yes,” “probably not,” and “definitely not.” If the given response for any of these three questions was anything other than “definitely not” (coded as 0), the respondent was categorized as susceptible to using e-cigarettes (coded as 1) [
      • Pierce J.P.
      • Choi W.S.
      • Gilpin E.A.
      • et al.
      Validation of susceptibility as a predictor of which adolescents take up smoking in the United States.
      ,
      • Pierce J.P.
      • Distefan J.M.
      • Kaplan R.M.
      • Gilpin E.A.
      The role of curiosity in smoking initiation.
      ].

      Exposure to e-cigarette marketing

      Self-reported exposure to e-cigarette marketing served as the independent variable. Channels of exposure to e-cigarette marketing included: the Internet; newspapers/magazines; retail stores; and when watching TV/movies (e.g., “When you are using the Internet, how often do you see ads or promotions for electronic cigarettes or e-cigarettes?” “When you read newspapers or magazines, how often do you see ads or promotions for electronic cigarettes or e-cigarettes?” “When you go to a convenience store, supermarket, or gas station, how often do you see ads or promotions for electronic cigarettes or e-cigarettes?”, and “When you watch TV or go to the movies, how often do you see ads or promotions for electronic cigarettes or e-cigarettes?”) Response options ranged from “never,” “rarely,” “sometimes,” “most of the time,” or “always.”
      Consistent with previous research [
      • Agaku I.
      • Ayo-Yusuf O.
      The effect of exposure to pro-tobacco advertising on experimentation with emerging tobacco products among U.S. adolescents.
      ,
      • Singh T.
      • Marynak K.
      • Arrazola R.A.
      • et al.
      Vital signs: Exposure to electronic cigarette advertising among middle school and high school students – United States, 2014.
      ,
      • Dube S.R.
      • Arrazola R.A.
      • Lee J.
      • et al.
      Pro-tobacco influences and susceptibility to smoking cigarettes among middle and high school students – United stated, 2011.
      ] respondents who answered “sometimes,” “most of the time,” or “always” were categorized as being exposed to the respective channel of e-cigarette marketing (coded as 1). Respondents who answered “never,” “rarely,” as well as those who stated they did not use the Internet, read newspapers/magazines, visit retail stores, or watch TV/movies, were categorized as unexposed (coded as 0).

      Covariates

      Sociodemographic factors and current combustible tobacco use were included as covariates. Race/ethnicity was categorized as: white, non-Hispanic; black, non-Hispanic; Hispanic; and other. Other included Asian, non-Hispanic; American Indian/Alaska Native, non-Hispanic; and Native Hawaiian and other Pacific Islander, non-Hispanic. Gender was dichotomized into male (coded as 0)/female (coded as 1). Grade level was coded as middle school (0) or high school (1). Current use of any combustible tobacco product was defined as use of a combustible tobacco product within the past 30 days. These products included: cigarettes, cigars, cigarillos, little cigars, pipe tobacco, bidis, and hookah. Any subject that responded “yes” to use of any of these products within the past 30 days was considered a current combustible tobacco user (coded as 1). All other students were considered nonusers (coded as 0).

      Statistical analysis

      Data were weighted to be representative of US middle school and high school students and to adjust for nonresponse and probability of selection. Multivariate logistic regression models assessed the relationship between e-cigarette marketing exposure and (1) current e-cigarette use and (2) ever e-cigarette use. Furthermore, a subpopulation analysis was performed among students who reported they had never used e-cigarettes whereby multivariate logistic regression models assessed the association between both individual and cumulative exposure to e-cigarette marketing and susceptibility to e-cigarette use. For models assessing cumulative exposure, the independent variable of interest was exposure to number of e-cigarette marketing channels, a variable ranging from zero to four that was created by summing the number of channels (including internet, magazine/newspaper, retail, and TV/movies). To determine the odds of use and susceptibility for an individual exposed to all four types of e-cigarette marketing, we exponentiated the beta coefficient multiplied by four: OR4 = exp(β × 4) [
      • Newton H.J.
      • Cox N.J.
      Interpreting logistic regression in all its forms.
      ]. The following covariates were included in all models: sex, race/ethnicity, grade, and current use of any combustible tobacco product. For the included variables, missing data due to nonresponse ranged from .8%–6.7%. Therefore, the sample size for each model varied minimally. All analyses were conducted using STATA 14.0 (College Station, TX).

      Results

      Descriptive statistics

      Nearly half of the sample (49.8%) was female and 56.1% were in high school. In terms of race/ethnicity status, 53.2% were non-Hispanic white, 14.6% were non-Hispanic black, 21.9% were Hispanic, and 10.3% were classified as other. In regard to e-cigarette use, 19.8% of youth reported ever use and 9.3% reported current use of e-cigarettes whereas 32.8% of never users were susceptible to use. Retail advertising and promotions (54.8%) were the most prevalent source of marketing exposure, followed by internet (39.8%), TV/movies (36.5%), and print media (30.4%).

      E-cigarette ever use

      As seen in Table 1, exposure to e-cigarette marketing via Internet, print, retail, and TV/movies was significantly associated with ever use of e-cigarettes when adjusting for sex, race/ethnicity, grade, and other tobacco use. With each additional exposure to another channel of e-cigarette marketing, students' odds of ever use of e-cigarettes increased by 1.16 when adjusting for sex, race/ethnicity, grade, and other tobacco use (Table 2). Given that these odds are for a one unit change in the predictor, we further considered the effect of exposure to all marketing channels rather than just one. Thus, for students who were exposed to four channels of e-cigarette marketing, the odds of ever e-cigarette use increased by 1.81.
      Table 1Association between e-cigarette use/susceptibility and exposure to individual pro e-cigarette marketing among middle school and high school students, (National Youth Tobacco Survey, 2014, n = 22,007)
      Current e-cigarette use (9.3%)Ever e-cigarette use (19.8%)Susceptibility to e-cigarettes, among never users (32.8%)
      adjOR
      Odds ratio adjusted for sex, grade, race/ethnicity, and past 30-day use of other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, and hookah.
      (95% CI)
      adjOR
      Odds ratio adjusted for sex, grade, race/ethnicity, and past 30-day use of other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, and hookah.
      (95% CI)
      adjOR
      Odds ratio adjusted for sex, grade, race/ethnicity, and past 30-day use of other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, and hookah.
      (95% CI)
      Internet1.68** (1.45–1.95)1.61** (1.41–1.83)1.38** (1.26–1.51)
      Print1.36** (1.15–1.60)1.22* (1.07–1.39)1.22** (1.10–1.35)
      Retail1.27** (1.19–1.35)1.61** (1.43–1.80)1.30** (1.20–1.41)
      TV/movies1.41* (1.22–1.62)1.20* (1.07–1.35)1.16* (1.07–1.27)
      *p < .01; **p < .001.
      adjOR = adjusted odds ratio; CI = confidence interval.
      a Odds ratio adjusted for sex, grade, race/ethnicity, and past 30-day use of other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, and hookah.
      Table 2Association between e-cigarette use/susceptibility and cumulative exposure to number of pro e-cigarette marketing channels (National Youth Tobacco Survey, 2014)
      Past 30 e-cigarette day use (all students, n = 22,007)Ever e-cigarette use (all students, n = 22,007)Susceptibility to e-cigarette use
      Susceptibility to E-cigarette Use is (yes=1, no=0) where a response of “Definitely yes,” “Probably yes,” or “Probably not” to any of the following 3 questions is considered susceptible (1): “Have you ever been curious about using an electronic cigarette or e-cigarette such as Blu, 21st Century Smoke or NJOY?” / “Do you think that you will try an electronic cigarette or e-cigarette soon?” / “If one of your best friends were to offer you an electronic cigarette or e-cigarette, would you use it?” Only those that responded “Definitely not” to all three questions were considered not susceptible (0).
      (never users of e-cigarettes, n = 17,286)
      Adjusted OR (95% CI)p valueAdjusted OR (95% CI)p valueAdjusted OR (95% CI)p value
      Advertising Exposure
      Sum of number of e-cigarette advertising sources exposed (including internet, print, retail, and TV/movies) ranging from 0–4; exposed is answering “sometimes,” “most of the time,” or “always.”
       Exposure to pro e-cig marketing sources1.22 (1.15–2.02)<.0011.16 (1.11–1.22)<.0011.11 (1.08–1.15)<.001
      Grade
       High school2.37 (1.61–3.50)<.0012.50 (1.94–3.21)<.0011.20 (1.06–1.35).003
      Sex
       Female.81 (.70–.93).004.82 (.73–.93).003.98 (.89–1.07).644
      Race/ethnicity
       Black, non-Hispanic.40 (.25–.64)<.001.60 (.44–.83).002.92 (.79–1.07).275
       Hispanic1.01 (.73–1.40).9551.12 (.92–1.35).2561.40 (1.25–1.57)<.001
       Other
      “Other” is where a response was “Asian, non-Hispanic;” “American Indian/Alaska Native, non-Hispanic;” or “native Hawaiian and other Pacific Islander, non-Hispanic.”
      .89 (.61–1.29).526.99 (.81–1.21).9291.17 (1.03–1.33).015
      Other tobacco use
      Past 30 day use of any other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, hookah.
      15.66 (13.09–18.73)<.00112.65 (10.66–15.00)<.0012.57 (2.10–3.16)<.001
      Bold represents a statistically significant value at p < .05.
      CI = confidence interval; OR = odds ratio.
      a Susceptibility to E-cigarette Use is (yes=1, no=0) where a response of “Definitely yes,” “Probably yes,” or “Probably not” to any of the following 3 questions is considered susceptible (1): “Have you ever been curious about using an electronic cigarette or e-cigarette such as Blu, 21st Century Smoke or NJOY?” / “Do you think that you will try an electronic cigarette or e-cigarette soon?” / “If one of your best friends were to offer you an electronic cigarette or e-cigarette, would you use it?” Only those that responded “Definitely not” to all three questions were considered not susceptible (0).
      b Sum of number of e-cigarette advertising sources exposed (including internet, print, retail, and TV/movies) ranging from 0–4; exposed is answering “sometimes,” “most of the time,” or “always.”
      c “Other” is where a response was “Asian, non-Hispanic;” “American Indian/Alaska Native, non-Hispanic;” or “native Hawaiian and other Pacific Islander, non-Hispanic.”
      d Past 30 day use of any other tobacco products (yes/no) including cigarettes, cigars/cigarillos, snuff, pipe, bidis, hookah.

      Current e-cigarette use

      As seen in Table 1, exposure to e-cigarette marketing via Internet, print, retail, and TV/movies was significantly associated with current e-cigarette use among middle and high school students when adjusting for sex, race/ethnicity, grade, and other tobacco use. Furthermore, with each additional exposure to another channel of e-cigarette marketing, students' odds of current e-cigarette use increased by 1.22 when adjusting for sex, race/ethnicity, grade, and other tobacco use (Table 2). Again, for students who were exposed to four channels of e-cigarette marketing, the odds of current e-cigarette use increased by 2.22.

      Susceptibility to e-cigarette use

      As seen in Table 1, among youth who had never used e-cigarettes, exposure to e-cigarette marketing via Internet, print, retail, and TV/movies was significantly associated with susceptibility to e-cigarette use. Moreover, among youth who had never used e-cigarettes, with each additional exposure to another channel of e-cigarette marketing, students' odds of susceptibility to e-cigarette use increased by 1.11 when adjusting for sex, race/ethnicity, grade, and other tobacco use (Table 2). For students who were exposed to four channels of e-cigarette marketing, the odds of current e-cigarette use increased by 1.52.

      Discussion

      To our knowledge, this is the first study to investigate the association between exposure to e-cigarette marketing from several channels and use/susceptibility of e-cigarettes using a nationally representative sample. However, findings are consistent with studies showing an association between exposure to advertising and promotional activities for conventional tobacco and the use of cigarettes [
      U.S. Department of Health and Human Services
      The health consequences of smoking-50 years of progress: A report of the Surgeon General.
      ] and emerging tobacco products [
      • Agaku I.
      • Ayo-Yusuf O.
      The effect of exposure to pro-tobacco advertising on experimentation with emerging tobacco products among U.S. adolescents.
      ], as well as susceptibility to e-cigarette use [
      • Farrelly M.
      • Duke J.
      • Porter L.
      • et al.
      A randomized trial of the effect of e-cigarette TV advertisements on intentions to use e-cigarettes.
      ]. In particular, Pierce et al. [
      • Pierce J.P.
      • Choi W.S.
      • Gilpin E.A.
      • et al.
      Validation of susceptibility as a predictor of which adolescents take up smoking in the United States.
      ,
      • Pierce J.P.
      • Distefan J.M.
      • Kaplan R.M.
      • Gilpin E.A.
      The role of curiosity in smoking initiation.
      ] showed that nonsusceptible, nonusing teens became susceptible to smoking after exposure to cigarette marketing, and that susceptibility was a significant predictor of onset in adolescence.
      Our findings indicate that exposure to e-cigarette marketing from all channels is significantly associated with increased likelihood of adolescents' e-cigarette use. Furthermore, there was a significant and increasingly stronger relationship between cumulative exposure (i.e., with each additional channel exposed, an increase in odds of use was observed) to e-cigarette marketing and current and ever use of e-cigarettes among adolescents. These findings suggest that youth who are exposed to e-cigarette marketing via multiple channels have an increased likelihood of also using e-cigarettes. Results extend previous research which found a dose-response relationship in exposure to conventional tobacco advertising and both cigarette and alternative tobacco product use [
      • Agaku I.
      • Ayo-Yusuf O.
      The effect of exposure to pro-tobacco advertising on experimentation with emerging tobacco products among U.S. adolescents.
      ]. This study highlights widespread environmental influences promoting e-cigarette use through a variety of platforms, and that these influences increase the odds that a young person might also be using e-cigarettes.
      In our subpopulation analysis, we also found a significant association between exposure to e-cigarette marketing via all channels and susceptibility to use e-cigarettes among youth who had never used e-cigarettes. Furthermore, among these students who had never used e-cigarettes, there was a significant relationship between cumulative exposure to e-cigarette marketing and susceptibility to e-cigarette use. These findings indicate that youth who are exposed to multiple channels of e-cigarette marketing have increased susceptibility to use e-cigarettes. As noted previously, susceptibility to tobacco use is an established predictor of future tobacco use [
      • Pierce J.P.
      • Choi W.S.
      • Gilpin E.A.
      • et al.
      Validation of susceptibility as a predictor of which adolescents take up smoking in the United States.
      ,
      • Pierce J.P.
      • Distefan J.M.
      • Kaplan R.M.
      • Gilpin E.A.
      The role of curiosity in smoking initiation.
      ]; this finding raises concern about the role of e-cigarette marketing in recruiting new e-cigarette users. Future longitudinal research is warranted to determine the temporality of this relationship.
      The association between exposure to e-cigarette marketing and product use is of particular concern as e-cigarette marketing expenditures continue to rapidly increase [
      • Kim A.E.
      • Arnold K.Y.
      • Makarenko O.
      E-cigarette advertising expenditures in the U.S., 2011-2012.
      ,
      • Kornfield R.
      • Huang J.
      • Vera L.
      • Emery S.L.
      Industry watch: Rapidly increasing promotional expenditures for e-cigarettes.
      ]. Annual e-cigarette advertising expenditures tripled from 2011 to 2012, increasing from $6.4 million to $18.3 million (Kim et al. [
      • Kim A.E.
      • Arnold K.Y.
      • Makarenko O.
      E-cigarette advertising expenditures in the U.S., 2011-2012.
      ]). Furthermore, expenditures through the second quarter of 2013 outpaced all of 2012 [
      • Kornfield R.
      • Huang J.
      • Vera L.
      • Emery S.L.
      Industry watch: Rapidly increasing promotional expenditures for e-cigarettes.
      ] suggesting this trend is not likely to change. Over this time, youth exposure to e-cigarette marketing tripled [
      • Emery S.L.
      • Vera L.
      • Huang J.
      • Szczypka G.
      Wanna know about vaping? Patterns of message exposure, seeking and sharing information about e-cigarettes across media platforms.
      ], and this is particularly worrisome given the associations documented in this article.
      This study has some limitations. First, the analyses were cross-sectional which prohibits causal inference. For example, e-cigarette users or those more susceptible to e-cigarette use may be more likely to notice e-cigarette marketing, and report greater exposure. Thus, longitudinal data are critically needed. Other studies have demonstrated a causal relationship between marketing exposure and adolescent risk behavior [
      U.S. Department of Health and Human Services
      Preventing tobacco use among youth and young adults: A report of the Surgeon General.
      ,
      • Biener L.
      • Siegel M.
      Tobacco marketing and adolescent Smoking: More support for a causal inference.
      ]; however, with the relative novelty of e-cigarettes, longitudinal data that are necessary to support a temporal relationship are not yet available. Thus, this article serves as a point or origin for including e-cigarette marketing in the established literature of marketing exposure and adolescent risk behavior. Note that the odds ratios presented in this manuscript remain significant when controlling for concomitant combustible tobacco use (cigarettes, cigars and so forth), which is a strong predictor of e-cigarette use. Previous studies examining conventional cigarette use and marketing exposure have seldom controlled for dual/poly tobacco use [
      • Biener L.
      • Siegel M.
      Tobacco marketing and adolescent Smoking: More support for a causal inference.
      ,
      • Pierce J.P.
      • Choi W.S.
      • Gilpin E.A.
      • et al.
      Tobacco industry promotion of cigarettes and adolescent smoking.
      ,
      • Altman D.G.
      • Levine D.W.
      • Coeytaux R.
      • et al.
      Tobacco promotion and susceptibility to tobacco use among adolescents aged 12 through 17 years in a nationally representative sample.
      ], thus, highlighting the robustness of our findings. Second, data are self-reported and are subject to recall bias, although these data are consistent with other large national data sets. Third, the single-item measures used to assess exposure to e-cigarette marketing may be less psychometrically robust than multiple-item measures. Nevertheless, this study has implications for public health in terms of regulation of e-cigarettes and prevention campaigns, especially since prior associations between cigarette marketing and cigarette use among youth have been shown to be causally related, with marketing exposure predicting subsequent onset and prevalence of cigarette smoking [
      U.S. Department of Health and Human Services
      The health consequences of smoking-50 years of progress: A report of the Surgeon General.
      ].
      Thus, in terms of the need to be precautionary, it seems prudent to develop policies and programs to discourage e-cigarette use among young people. Although research on the short- and long-term health consequences of e-cigarette use is still developing, exposure to nicotine during adolescence can negatively impact brain development [
      • Galván A.
      • Schonberg T.
      • Mumford J.
      • et al.
      Greater risk sensitivity of dorsolateral prefrontal cortex in young smokers than in nonsmokers.
      ,
      • Treur J.
      • Willemsen G.
      • Vink J.
      • et al.
      Smoking during adolescence as a risk factor for attention problems.
      ]. The increasing reach and intensity [
      • Singh T.
      • Marynak K.
      • Arrazola R.A.
      • et al.
      Vital signs: Exposure to electronic cigarette advertising among middle school and high school students – United States, 2014.
      ] of e-cigarette marketing, along with the potential for these messages to recruit adolescent users, highlights the need for regulation of marketing strategies that are used by these companies to prevent and reduce adolescent initiation of these products.

      Funding Sources

      This work was supported by grant number [ 1 P50 CA180906-01 ] from the National Cancer Institute at the National Institutes of Health and the Food and Drug Administration, Center for Tobacco Products (CTP) . National Institutes of Health and the Food and Drug Administration had no role in the study design, collection, analysis or interpretation of the data, writing the manuscript, or the decision to submit the article for publication.

      References

        • Arrazola R.
        • Singh T.
        • Caraballo R.
        • et al.
        Tobacco use among middle and high school students – United States, 2011-2014.
        MMWR Morb Mortal Wkly Rep. 2015; 64: 381-385
        • Cheng T.
        Chemical evaluation of electronic cigarettes.
        Nicotine Tob Res. 2014; 23: ii11-ii17
        • Kosmider L.
        • Sobczak A.
        • Goniewicz M.
        • et al.
        Carbonyl compounds in electronic cigarette vapors: Effects of nicotine solvent and battery output voltage.
        Nicotine Tob Res. 2014; 16: 1319-1326
        • U.S. Department of Health and Human Services
        The health consequences of smoking-50 years of progress: A report of the Surgeon General.
        U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, Atlanta, GA2014
        • Galván A.
        • Schonberg T.
        • Mumford J.
        • et al.
        Greater risk sensitivity of dorsolateral prefrontal cortex in young smokers than in nonsmokers.
        Psychopharmacology. 2013; 229: 345-355
        • Treur J.
        • Willemsen G.
        • Vink J.
        • et al.
        Smoking during adolescence as a risk factor for attention problems.
        Biol Psychiatry. 2015; 78: 656-663
        • Moylan S.
        • Jacka F.
        • Pasco J.
        • Berk M.
        Cigarette smoking, nicotine dependence and anxiety disorders: A systematic review of population-based, epidemiological studies.
        BMC Med. 2012; 10: 123-136
        • Cavalca E.
        • Kong G.
        • Krishnan-Sarin S.
        • et al.
        A preliminary experimental investigation of peer influence on risk-taking among adolescent smokers and non-smokers.
        Drug Alcohol Depend. 2013; 129: 163-166
        • Anand V.
        • McGinty K.L.
        • O'Brien K.
        • et al.
        E-cigarette use and beliefs among urban public high school students in North Carolina.
        J Adolesc Health. 2015; 57: 46-51
        • Bunnell R.
        • Agaku I.
        • King B.
        • et al.
        Intentions to smoke cigarettes among never-smoking US middle and high school electronic cigarette users: National Youth Tobacco Survey, 2011–2013.
        Nicotine Tob Res. 2015; 17: 228-235
        • U.S. Department of Health and Human Services
        Preventing tobacco use among youth and young adults: A report of the Surgeon General.
        U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, Atlanta, GA2012
        • Biener L.
        • Siegel M.
        Tobacco marketing and adolescent Smoking: More support for a causal inference.
        Am J Public Health. 2000; 90: 407-411
        • Farrelly M.
        • Duke J.
        • Porter L.
        • et al.
        A randomized trial of the effect of e-cigarette TV advertisements on intentions to use e-cigarettes.
        Am J Prev Med. 2015; 49: 686-693
        • Agaku I.
        • Ayo-Yusuf O.
        The effect of exposure to pro-tobacco advertising on experimentation with emerging tobacco products among U.S. adolescents.
        Health Education Behav. 2014; 41: 275-280
        • Kim A.E.
        • Arnold K.Y.
        • Makarenko O.
        E-cigarette advertising expenditures in the U.S., 2011-2012.
        Am J Prev Med. 2014; 46: 409
        • Baher R.Z.
        • Hua M.
        • Talbot P.
        Puffing topography and nicotine intake of electronic cigarette use.
        PLoS One. 2015; 10: e117222
        • Institute for Global Tobacco Control
        Country laws regulating e-cigarettes: A policy scan.
        Johns Hopkins Bloomberg School of Public Health, Baltimore, MD2015
        • Grana R.
        • Benowitz N.
        • Glantz S.A.
        Background paper on E-cigarettes (electronic nicotine delivery systems).
        Center for Tobacco Control Research and Education, University of California, San Francisco, a WHO Collaborating Center on Tobacco Control, San Francisco, CA2013 (Prepared for World Health Organization Tobacco Free Initiative. Available at: http://pvw.escholarship.org/uc/item/13p2b72n. Accessed November 10, 2016.)
        • Sebastian M.
        E-cig marketing budgets growing by more than 100% year over year.
        Advertisement Age, New York, NY2014 (Available at:) (Accessed May 29, 2014)
        • Singh T.
        • Marynak K.
        • Arrazola R.A.
        • et al.
        Vital signs: Exposure to electronic cigarette advertising among middle school and high school students – United States, 2014.
        MMWR Mortal Wkly Rep. 2016; 64: 1403-1408
        • Truth Initiative
        Vaporized: Youth and young adult exposure to e-cigarette marketing.
        2015 (Available at:) (Accessed April 22, 2016)
        • National Youth Tobacco Survey (NYTS)
        Centers for Disease Control and Prevention Web site.
        2015 (Available at:) (Accessed January 8, 2016)
        • Pierce J.P.
        • Choi W.S.
        • Gilpin E.A.
        • et al.
        Validation of susceptibility as a predictor of which adolescents take up smoking in the United States.
        Health Psychol. 1996; 15: 355-361
        • Dube S.R.
        • Arrazola R.A.
        • Lee J.
        • et al.
        Pro-tobacco influences and susceptibility to smoking cigarettes among middle and high school students – United stated, 2011.
        J Adolesc Health. 2013; 52: S45-S51
        • Pierce J.P.
        • Distefan J.M.
        • Kaplan R.M.
        • Gilpin E.A.
        The role of curiosity in smoking initiation.
        Addict Behaviors. 2005; 30: 685-696
        • Newton H.J.
        • Cox N.J.
        Interpreting logistic regression in all its forms.
        Stata Technical Bulletin, College Station, TX2000 (STB-53. Available at:) (Accessed on February 24, 2016)
        • Kornfield R.
        • Huang J.
        • Vera L.
        • Emery S.L.
        Industry watch: Rapidly increasing promotional expenditures for e-cigarettes.
        Tob Control. 2015; 24: 110-111
        • Emery S.L.
        • Vera L.
        • Huang J.
        • Szczypka G.
        Wanna know about vaping? Patterns of message exposure, seeking and sharing information about e-cigarettes across media platforms.
        Tob Control. 2014; 23: iii17-iii25
        • Pierce J.P.
        • Choi W.S.
        • Gilpin E.A.
        • et al.
        Tobacco industry promotion of cigarettes and adolescent smoking.
        JAMA. 1998; 279: 511-515
        • Altman D.G.
        • Levine D.W.
        • Coeytaux R.
        • et al.
        Tobacco promotion and susceptibility to tobacco use among adolescents aged 12 through 17 years in a nationally representative sample.
        Am J Public Health. 1996; 86: 1590-1593