981575121797Nicotine Tob ResNicotine Tob. Res.Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco1462-22031469-994X23449421457056110.1093/ntr/ntt013HHSPA722030ArticleAwareness and Ever Use of Electronic Cigarettes Among U.S. Adults, 2010–2011KingBrian A.PhD, MPH12AlamSuhanaMPH13PromoffGabbiMA1ArrazolaReneMPH1DubeShanta R.PhD, MPH1Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GAEpidemic Intelligence Service, Division of Applied Sciences, Scientific Education and Professional Development Program Office, Centers for Disease Control and Prevention, Atlanta, GAOak Ridge Institute for Science and Education, Oak Ridge, TNCorresponding Author: Brian A. King, Ph.D., M.P.H., Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, 4770 Buford Highway, MS K-50, Atlanta, GA 30341, USA. Telephone: 770.488.5107; Fax: 770.488.5848; baking@cdc.gov1092015282201392013159201515916231627Introduction

Electronic cigarettes, or e-cigarettes, were introduced into the U.S. market in recent years. However, little is known about the health impact of the product or the extent of its use. This study assessed the prevalence and correlates of awareness and ever use of e-cigarettes among U.S. adults during 2010–2011.

Methods

Data were obtained from the HealthStyles survey, a national consumer-based survey of U.S. adults aged ≥18 years old. In 2010, data collection for the HealthStyles survey was both mail-based (n = 4,184) and web-based (n = 2,505), and in 2011, web-based (n = 4,050) only. Estimates of awareness and ever use of e-cigarettes were calculated overall and by sex, age, race/ ethnicity, educational attainment, household income, region, and smoking status.

Results

In 2010, overall awareness of e-cigarettes was 38.5% (mail survey) and 40.9% (web survey); in 2011, awareness was 57.9% (web survey). Ever use of e-cigarettes among all respondents was 2.1% in the 2010 mail survey, 3.3% in the 2010 web survey, and 6.2% in the 2011 web survey. Ever use of e-cigarettes was significantly higher among current smokers compared with both former and never-smokers, irrespective of survey method or year. During 2010–2011, ever use increased among both sexes, those aged 45–54 years, non-Hispanic Whites, those living in the South, and current and former smokers.

Conclusions

Awareness and ever use of e-cigarettes increased among U.S. adults from 2010 to 2011. In 2011, approximately 1 in 5 current smokers reported having ever used e-cigarettes. Continued surveillance of e-cigarettes is needed for public health planning.

INTRODUCTION

Electronic cigarettes, or e-cigarettes, are battery powered devices that provide inhaled doses of nicotine and other additives to the user (Food and Drug Administration [FDA], 2009). Depending on the brand, e-cigarette cartridges typically contain nicotine, humectants to produce the vapor (e.g., propylene glycol or glycerol), and flavorings (e.g., tobacco, mint, fruit, chocolate) (Etter, Bullen, Flouris, Laugesen, & Eissenberg, 2011). Since becoming available in the United States, e-cigarettes have been promoted as being more cost-effective, amenable to use in smoking-restricted environments, and socially acceptable than traditional cigarettes (Cobb, Byron, Abrams, & Shields, 2010; Henningfield & Zaatari, 2010). E-cigarettes have also been marketed as smoking cessation aids (FDA, 2010a, 2010b, 2010c, 2010d, 2010e). However, there is currently no conclusive scientific evidence that e-cigarettes promote long-term cessation (Etter et al., 2011), and e-cigarettes are not included as a recommended smoking cessation method by the U.S. Public Health Service (PHS, 2008).

The Family Smoking Prevention and Tobacco Control Act of 2009 gave the U.S. FDA the authority to regulate tobacco products, including the ability to propose certain requirements and restrictions on manufacturing, marketing, and distribution (Government Printing Office [GPO], 2009). The Act defines a tobacco product, in part, as any product made or derived from tobacco that is not a drug, device, or combination product under the Act. In 2010, the U.S. Court of Appeals held that e-cigarettes and other products made or derived from tobacco can be regulated as tobacco products under the Act unless they are marketed for therapeutic purposes, in which case they are regulated as drugs and/or devices (D.C. Circuit, U.S. Court of Appeals, 2010). Currently, e-cigarettes that are marketed for therapeutic purposes are regulated by the FDA Center for Drug Evaluation and Research (FDA, 2012). The FDA Center for Tobacco Products currently regulates cigarettes, cigarette tobacco, roll-your-own tobacco, and smokeless tobacco (FDA, 2012), and in 2011, announced its intent to expand jurisdiction to all tobacco products, including e-cigarettes (GPO, 2011).

Many public health professionals are concerned that e-cigarettes may have an adverse impact on users’ health, encourage smoking initiation, perpetuate the use of nicotine and tobacco products among smokers who might otherwise quit, and counter the effectiveness of smoke-free policies (Etter et al., 2011; Henningfield & Zaatari, 2010). Potentially harmful constituents also have been identified in some e-cigarette cartridges (Cobb et al., 2010; FDA, 2009). Conversely, proponents of e-cigarettes contend that the product is markedly less harmful to health than traditional cigarettes and may help some smokers quit (Cahn & Siegel, 2011). Although e-cigarettes are becoming increasingly popular (Ayers, Ribisl, & Brownstein, 2011), data on awareness and use of the product are limited (McMillen, Maduka, & Winickoff, 2012; Pearson, Richardson, Niaura, Vallone, & Abrams, 2012). A recent study found that awareness of e-cigarettes doubled from 16.4% in 2009 to 32.2% in 2010, whereas ever use among those aware of the product quadrupled from 0.6% to 2.7% (Regan, Promoff, Dube, & Arrazola, 2011). However, no known study has assessed more recent changes in e-cigarette awareness and use. To address this need, we analyzed data from the 2010 and 2011 HealthStyles surveys to determine estimates of the prevalence and sociodemographic correlates of awareness and ever use of e-cigarettes among U.S. adults.

METHODSData Source

Data were obtained from Styles, a series of national consumer panel surveys administered in seasonal waves. The HealthStyles survey assesses exposure to health-related information and self-reported symptoms, risk factors, and diseases among U.S. adults aged ≥18 years old. In preparation for transitioning to online-only methodology, both mail (August– September) and web (July–August) versions of HealthStyles were fielded in 2010. Only a web (July–August) version was fielded in 2011.

Sample

For the 2010 mail-based Styles, sampling and data collection were conducted by Synovate, Inc., which recruited consumers to join a mail panel. Stratified random sampling (by region, household income, population density, age, and household size) of the panel was used to select a nationally representative sample, which received the ConsumerStyles survey. The 2010 mail-based HealthStyles was sent to households that completed ConsumerStyles (n = 6,255).

For the 2010 and 2011 web-based Styles, sampling and data collection were conducted by Knowledge Networks, which recruited a nationally representative online panel. Panel members are randomly recruited by probability-based sampling (random-digit dial and address based) to reach respondents regardless of whether they have a landline phone or Internet access. Households are provided with a computer and Internet access as needed. The panel is continuously replenished and maintains approximately 50,000 panelists. A random sample of 3,922 and 5,865 panelists were asked to participate in the 2010 and 2011 web-based HealthStyles, respectively.

Final sample sizes were 4,184 for the 2010 mail survey, 2,505 for the 2010 web survey, and 4,050 for the 2011 web survey. Response rates were 66.9%, 64.0%, and 69.0%, respectively.

MeasuresAwareness

Awareness of e-cigarettes was assessed using the question, “Which, if any, of the following products have you heard of?” Respondents who selected “electronic cigarettes or e-cigarettes” were considered aware of e-cigarettes.

Ever Use

Ever use of e-cigarettes was assessed using the question, “Have you ever tried any of the following products, even just one time?” Respondents who selected “electronic cigarettes or e-cigarettes” were considered ever e-cigarette users.

Respondent Characteristics

Respondent characteristics included sex, age, race/ethnicity, education, annual household income, U.S. Census region, and smoking status. Current smokers were defined as respondents who smoked ≥100 cigarettes in their lifetime and now smoked everyday or somedays.

Analysis

Data were analyzed using SAS v. 9.2 and weighted according to 2010 and 2011 Current Population Survey population distributions. National prevalence estimates and 95% CIs were calculated. Differences were considered statistically significant if CIs did not overlap. Estimates with a relative SE of ≥40% were not reported.

RESULTSAwareness

Awareness of e-cigarettes was 38.5% in the 2010 mail survey, 40.9% in the 2010 web survey, and 57.9% in the 2011 web survey (Table 1). No significant difference in awareness of e-cigarettes was observed between males and females, irrespective of survey method or year. In all three surveys, awareness of e-cigarettes was significantly lower among individuals ≥65 years old compared with younger age groups, and significantly lower among non-Hispanic Blacks compared with non-Hispanic Whites. Awareness of e-cigarettes was significantly lower among those with less than a high school education in the 2010 mail and 2011 web surveys, but no significant difference was observed by education level in the 2011 mail survey. No consistent differences in awareness of e-cigarettes were observed by income level or U.S. region across surveys. By smoking status, awareness of e-cigarettes was significantly higher among current smokers compared with former and never-smokers, regardless of survey method or year. When compared with the 2010 web survey, awareness of e-cigarettes in the 2011 web survey increased among all subpopulations except for those aged 18–34 years, Hispanics, those of non-Hispanic “Other” race, those with less than a high school education, and those with annual household income <$25,000.

Ever Use

Ever use of e-cigarettes was 2.1% in the 2010 mail survey, 3.3% in the 2010 web survey, and 6.2% in the 2011 web survey (Table 1). Irrespective of survey method or year, no significant difference in ever use of e-cigarettes was observed by sex, age, race/ethnicity, education, income, or U.S. region. In all three surveys, ever use of e-cigarettes was significantly higher among current smokers compared with both former and never-smokers. Among current smokers, ever use of e-cigarettes was 21.2% in the 2011 web survey compared with 6.8% in the 2010 mail survey and 9.8% in the 2010 web survey. When compared with the 2010 web survey, ever use of e-cigarettes in the 2011 web survey increased among both sexes, those aged 45–54 years, non-Hispanic Whites, those who live in the South, and both current and former smokers.

DISCUSSION

This study is the first to report changes in the national prevalence of e-cigarette awareness and use among U.S. adults between 2010 and 2011. The findings reveal that the awareness and use of e-cigarettes are increasing. Approximately 6 in 10 adults were aware of e-cigarettes in 2011 compared with 4 in 10 adults in 2010. Moreover, in 2011, 6.2% of all adults and 21.2% of current smokers had ever used e-cigarettes, representing an approximate doubling of 2010 estimates. These findings underscore the need for rigorous surveillance of e-cigarettes and their impact on smoking initiation, smoking cessation, concurrent use with combustible products, users’ health, and smoke-free policy compliance.

Differences in awareness and use of e-cigarettes were observed across subpopulations. Specifically, adults <65 years of age, non-Hispanic Whites, and current/former smokers were most aware of e-cigarettes. Higher awareness among younger adults may be related to the fact that e-cigarettes are traditionally marketed through electronic and social media (Noel, Rees, & Connolly, 2011; Yamin, Bitton, & Bates, 2010). In contrast, the only consistent statistically significant difference in e-cigarette use was between current smokers and nonsmokers. The higher prevalence of use among current smokers could be related to the marketing of e-cigarettes as smoking cessation aids (FDA, 2010a, 2010b, 2010c, 2010d, 2010e). Because e-cigarettes resemble traditional cigarettes and their use could potentially result in increased nicotine addiction and the initiation of tobacco smoking, further surveillance of e-cigarette use is warranted, particularly among youth and young adults, who are particularly susceptible to social and environmental influences to use tobacco (U.S. Department of Health and Human Services, 2012).

The impact of e-cigarette use on public health remains uncertain (Etter et al., 2011). Some research has shown that e-cigarettes are most frequently used as a smoking cessation aid (Etter, 2010), might alleviate the desire to smoke after abstinence (Bullen et al., 2010), and may reduce cigarette consumption and encourage short periods of smoking abstinence (Caponnetto, Polosa, Russo, Leotta, & Campagna, 2011; Polosa et al., 2011; Siegel, Tanwar, & Wood, 2011). However, e-cigarettes are presently unregulated and produced by numerous small manufacturers (Etter et al., 2011). Potentially harmful constituents have also been documented in some e-cigarette cartridges, including diethylene glycol, irritants, genotoxins, and animal carcinogens (Cobb et al., 2010; FDA, 2009). In addition, the tobacco industry is evolving rapidly. The e-cigarette manufacturer, blu Cigs, was recently acquired by Lorillard, Inc. (PR Newswire, 2012), and the product has been advertised as an alternative to cigarettes in a nationally televised commercial (Internet Movie Database, 2012). Other noncombustible nicotine products have been promoted by the tobacco industry as an alternative that allows smokers to access nicotine in situations where it is legally or socially unacceptable to smoke (Curry, Pederson, & Stryker, 2011). Accordingly, further research is needed on the long-term impact of e-cigarette use on tobacco cessation and initiation, concurrent product use, and users’ health.

The impact of e-cigarettes on smoke-free policy compliance should also be evaluated. The use of e-cigarettes in public areas in which cigarette smoking is prohibited could counter the effectiveness of these policies by complicating enforcement and giving the appearance that smoking is acceptable (Etter et al., 2011). Research suggests that smoke-free policies increase the social unacceptability of smoking and enhance quit intentions and behaviors (Brown, Moodie, & Hastings, 2009). To date, some states and localities have enacted policies that restrict e-cigarette use in public places, whereas others have exempted e-cigarettes from smoke-free legislation (Global Advisors Smoke-Free Policy, 2011).

This study is subject to at least four limitations. First, HealthStyles is not a population-based probability survey. Research suggests that random-digit-dial and Internet panel probability samples may be more representative than nonprobability Internet samples (Yeager et al., 2011). Nonetheless, data were weighted to be nationally representative and tobacco use estimates from Styles are consistent with other national household surveys (Regan et al., 2011). Second, data collection methods varied across surveys; however, estimates from the 2010 mail and web surveys were comparable. Third, small sample sizes for some subpopulations resulted in less precise estimates that could not be presented. Limited sample size also prevented the presentation of estimates of current e-cigarette use. Finally, survey responses were self-reported, which could lead to reporting bias; although studies have confirmed the validity of self-reported smoking (Caraballo, Giovino, & Pechacek, 2004), the accuracy of self-reported e-cigarette use is uncertain.

In conclusion, findings from the HealthStyles survey suggest that awareness and use of e-cigarettes increased among U.S. adults during 2010–2011, particularly among current smokers. Since e-cigarette use may continue to increase with time and could have either deleterious or beneficial effects on public health depending on its impact on smoking initiation and cessation, appropriate public health surveillance of the product is warranted.

ACKNOWLEDGMENTS

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

FUNDING

This project was supported in part by an appointment to the Research Participation Program at the Centers for Disease Control and Prevention (CDC) administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the CDC (DE-AC05-06OR23100).

DECLARATION OF INTEREST

None declared.

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Awareness and Ever Use of Electronic Cigarettes Among U.S. Adults—HealthStyles, 2010–2011

Awareness of electronic cigarettesa (% [95% CI])
Ever use of electronic cigarettesb (% [95% CI])
2010 Mail2010 Web2011 Web2010 Mail2010 Web2011 Web


Characteristicn = 4,184n = 2,505n = 4,050n = 4,184n = 2,505n = 4,050
Sex
 Male40.8 [37.4–44.2]44.1 [40.7–47.5]60.9 [57.9–63.8]2.3 [1.3–3.4]3.0 [1.9–4.2]5.8 [4.4–7.2]
 Female36.4 [32.7–40.1]37.9 [34.7–41.1]55.1 [52.2–58.0]1.9 [1.3–2.6]3.7 [2.4–4.9]6.6 [5.1–8.2]
Age (years)
 18–2447.4 [32.6–62.2]45.0 [37.4–52.6]56.8 [49.7–63.9] c 7.0 [3.0–10.9]8.1 [4.0–12.2]
 25–3448.6 [43.0–54.1]48.4 [42.6–54.3]58.3 [52.6–63.8]2.9 [1.1–4.7]3.1 [1.4–4.8]6.6 [3.9–9.3]
 35–4439.9 [35.8–43.9]43.7 [38.3–49.1]60.0 [55.4–64.6]3.4 [2.0–4.8]3.2 [1.4–5.0]5.7 [3.6–7.7]
 45–5442.8 [39.7–45.8]47.9 [42.6–53.2]65.4 [61.1–69.6]1.9 [1.0–2.8]3.2 [1.3–5.2]8.0 [5.5–10.5]
 55–6433.8 [30.1–37.4]37.7 [32.6–42.8]61.2 [56.8–65.6]2.2 [0.9–3.4]2.9 [1.1–4.8]5.5 [3.4–7.5]
 ≥6519.0 [16.2–21.7]21.4 [16.9–25.9]44.6 [40.0–49.2]0.8 [0.2–1.4] c 3.7 [1.9–5.4]
Race/ethnicity
 White, non-Hispanic42.5 [39.6–45.4]44.3 [41.5–47.2]62.6 [60.3–64.9]2.4 [1.6–3.2]3.8 [2.7–4.9]6.8 [5.6–8.1]
 Black, non-Hispanic26.6 [20.8–32.3]25.6 [19.7–31.4]50.0 [43.0–57.0] c c 4.5 [1.6–7.3]
 Other, non-Hispanic31.3 [23.6–39.0]41.8 [32.6–51.1]48.5 [39.4–57.6]1.8 [0.4–3.2] c 6.1 [1.8–10.4]
 Hispanic31.9 [23.3–40.6]36.2 [30.1–42.3]44.4 [37.8–51.1]2.3 [0.9–3.7]3.0 [1.0–5.1]3.9 [1.1–6.7]
Education
 Less than high school19.1 [12.8–25.3]40.3 [33.9–46.7]42.6 [35.0–50.2] c 4.3 [1.7–6.9]7.4 [3.4–11.4]
 High school graduate37.2 [32.3–42.0]41.0 [36.8–45.2]56.4 [52.6–60.3]3.1 [1.3–5.0]4.0 [2.2–5.7]7.5 [5.4–9.7]
 Some college41.3 [36.6–46.0]40.6 [36.3–44.9]62.5 [59.0–66.0]2.3 [1.4–3.2]3.6 [2.0–5.1]6.1 [4.6–7.7]
 College graduate39.3 [36.1–42.5]41.4 [36.8–45.9]61.7 [58.4–64.9]1.5 [0.7–2.2]2.0 [0.8–3.2]4.4 [2.9–5.9]
Annual household income
 <$15,00026.1 [21.1–31.1]42.6 [36.2–49.0]52.1 [45.2–58.9]1.1 [0.3–1.9]3.5 [1.5–5.6]7.5 [4.3–10.7]
 $15,000-$24,99931.8 [24.7–39.0]43.5 [36.0–50.9]54.6 [47.2–62.0]1.6 [0.4–2.9] c 5.7 [1.9–9.4]
 $25,000-$39,99939.5 [32.8–46.3]36.4 [31.1–41.6]55.9 [50.4–61.3]2.9 [0.6–5.2]3.5 [1.3–5.8]9.4 [5.7–13.0]
 $40,000-$59,99941.2 [35.3–47.1]41.7 [36.5–46.8]53.4 [48.4–58.4]1.9 [0.7–3.1]2.5 [1.1–3.8]4.9 [2.9–6.9]
 ≥$60,00042.7 [38.8–46.6]41.1 [37.3–44.8]61.8 [59.0–64.6]2.4 [1.5–3.3]3.5 [2.1–4.9]5.6 [4.3–7.0]
U.S. Census regiond
 Northeast35.3 [29.1–41.5]38.5 [32.7–44.3]57.3 [52.6–62.0]1.1 [0.3–1.9] c 5.6 [3.5–7.7]
 Midwest46.3 [41.3–51.3]46.6 [42.0–51.2]61.1 [57.0–65.1]3.3 [1.5–5.1]5.4 [3.1–7.6]7.7 [5.3–10.1]
 South35.3 [31.5–39.1]38.4 [34.4–42.4]57.9 [54.3–61.5]1.4 [0.8–2.0]2.5 [1.4–3.6]6.2 [4.4–8.0]
 West37.4 [31.4–43.4]41.3 [36.7–46.0]55.4 [51.0–59.7]3.0 [1.7–4.2]3.7 [2.0–5.5]5.3 [3.3–7.3]
Smoking status
 Current smokers58.5 [52.5–64.4]59.3 [54.2–64.3]76.9 [72.2–81.5]6.8 [4.6–8.9]9.8 [6.9–12.6]21.2 [17.0–25.4]
 Former smoker36.2 [31.8–40.5]41.5 [37.0–46.0]65.4 [61.7–69.1]0.6 [0.2–1.1]2.5 [0.8–4.2]7.4 [5.0–9.7]
 Never-smoker33.8 [30.4–37.3]34.6 [31.3–37.8]50.1 [47.3–52.9]1.2 [0.5–2.0]1.3 [0.5–2.0]1.3 [0.7–1.8]
Total38.5 [36.0–41.0]40.9 [38.6–43.2]57.9 [55.8–60.0]2.1 [1.5–2.7]3.3 [2.5–4.2]6.2 [5.2–7.3]

Note.

Defined as a response of “electronic cigarettes or e-cigarettes” to the question, “Which, if any, of the following products have you heard of?”

Defined as a response of “electronic cigarettes or e-cigarettes” to the question, “Have you tried any of the following products, even just one time?”

Relative SE ≥ 40%.

Northeast = Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont; Midwest = Indiana, Illinois, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin; South = Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, West Virginia; West = Alaska, Arizona, California, Colorado, Hawaii, Idaho, New Mexico, Montana, Oregon, Nevada, Utah, Washington, Wyoming.