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Original Research: Tobacco Cessation and Prevention |

Do e-Cigarettes Have the Potential to Compete With Conventional Cigarettes?Uptake of Electronic Cigarettes: A Survey of Conventional Cigarette Smokers’ Experiences With e-Cigarettes FREE TO VIEW

Eva Kralikova, MD, PhD; Jan Novak; Oliver West, MSc; Alexandra Kmetova, MD; Peter Hajek, PhD
Author and Funding Information

From the Institute of Hygiene and Epidemiology (Drs Kralikova and Kmetova and Mr Novak) and Tobacco Dependence Centre, 3rd Department of Medicine (Drs Kralikova and Kmetova), First Faculty of Medicine, Charles University in Prague and General University Hospital, Prague, Czech Republic; and UK Centre for Tobacco and Alcohol Studies (Mr West and Prof Hajek), Wolfson Institute of Preventive Medicine, Queen Mary, University of London, London, England.

Correspondence to: Peter Hajek, PhD, UK Centre for Tobacco and Alcohol Studies, Wolfson Institute of Preventive Medicine, Queen Mary, University of London, London, E1 2AD, England; e-mail: p.hajek@qmul.ac.uk


Funding/Support: The project was supported by AMVIS-KONTAKT ME 09014 and P25/LF1/2 grants to Dr Kralikova.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.


Chest. 2013;144(5):1609-1614. doi:10.1378/chest.12-2842
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Published online

Background:  Electronic cigarettes (ECs) are becoming increasingly popular globally. If they were to replace conventional cigarettes, it could have a substantial impact on public health. To evaluate EC’s potential for competing with conventional cigarettes as a consumer product, we report the first data, to our knowledge, on the proportion of smokers who try ECs and become regular users.

Methods:  A total of 2,012 people seen smoking or buying cigarettes in the Czech Republic were approached to answer questions about smoking, with no mention made of ECs to avoid the common bias in surveys of EC users. During the interview, the volunteers’ experience with ECs was then discussed.

Results:  A total of 1,738 smokers (86%) participated. One-half reported trying ECs at least once. Among those who tried ECs, 18.3% (95% CI, 0.15.7%-20.9%) reported using them regularly, and 14% (95% CI, 11.6%-16.2%) used them daily. On average, regular users used ECs daily for 7.1 months. The most common reason for using ECs was to reduce consumption of conventional cigarettes; 60% of regular EC users reported that ECs helped them to achieve this. Being older and having a more favorable initial experience with ECs explained 19% of the variance in progressing to regular EC use.

Conclusions:  Almost one-fifth of smokers who try ECs once go on to become regular users. ECs may develop into a genuine competitor to conventional cigarettes. Government agencies preparing to regulate ECs need to ensure that such moves do not create a market monopoly for conventional cigarettes.

Electronic cigarettes (ECs) are devices that generate a vapor by heating a liquid solution of propylene glycol or glycerine with different concentrations of nicotine. In the last few years, ECs have become increasingly popular globally.16 Their commercial success is leading to innovation and development, with new EC brands improving on the old ones.6,7

The emergence of this new phenomenon took the tobacco control community by surprise. The first reaction of most tobacco control experts has been conflicting.1,8,9 Several countries have banned ECs, and others are intending to submit them to the same strict regulation as medicines.911 More recently, however, commentators have started to point out that if ECs were capable of replacing cigarettes as a consumer product, such a development could have a positive impact on public health.1,6,7,1215 The absolute safety of ECs is unknown but they are likely to be considerably safer than conventional cigarettes.1,1618

Data on real-life EC users available so far have been obtained primarily via Internet surveys2,1922 or at EC users’ events.23 The problem with such surveys is that they are subject to a considerable self-selection bias. Someone who tried ECs, did not find them attractive or useful, and stopped using them is much less likely to respond to such surveys than enthusiasts who found ECs exceptionally helpful. Indeed, the existing surveys found that the majority of responders report that they are now ex-smokers or that ECs helped them to cut down, and that ECs were more effective for them than other approaches to cutting down or stopping smoking.

To our knowledge, only a few surveys evaluated experience with ECs among unselected populations,2426 and no survey so far has estimated the proportion of smokers who try ECs and become regular users. Such information is essential to assess the potential of ECs to compete with conventional cigarettes. If most smokers use ECs only once or twice for their novelty value, ECs are unlikely to lead to a large-scale reduction in the use of conventional cigarettes.

We set out to assess EC adoption rate in an unselected sample of smokers in the general population by interviewing people who smoked on the street or were buying cigarettes. We previously piloted this approach on a smaller sample.27 We then refined the methodology and the questionnaire and carried out the larger study reported here. The study was conducted in the Czech Republic, where 25% of the adult population smoke daily.28 As in most other European countries, ECs are available in tobacconist and specialist shops and on the Internet.

Later in this article, we use the words smokers, smoking, and cigarettes to denote the use of conventional cigarettes. When we discuss e-cigarettes, we use the phrase EC use.

Eighteen interviewers (graduate students) approached people who smoked on the street or were purchasing conventional cigarettes in 17 cities in the Czech Republic during May 2012. Smokers were asked if they would be willing to answer several brief questions about their smoking. Ethical approval was obtained from a local ethics committee of the General University Hospital in Prague (IRB 00002705, IORG 0002175 under number 1800/12/ S-IV).

No mention was made of ECs to avoid biasing the sample in favor of smokers who have experience with ECs. Smokers who agreed to take part were then asked a series of 11 questions about their smoking and their experience with ECs.

Interviewers recorded participants’ age, sex, the number of cigarettes they smoked per day (or per week, if they were nondaily smokers), and how soon after waking they smoked (within 5 min, between 5 and 30 min, between 31 min and 1 h, later than 1 h)

The EC questions and response options included:

  • 1. What is your experience with EC? (Never heard of them; Heard of them but did not try them; Tried them once; Tried them repeatedly; Use them regularly)

  • 2. If you ever tried EC, what was your first experience with them? (As expected; Disappointed; Pleasantly surprised)

  • 3. If you tried EC but do not use them regularly, what was the main reason you did not continue with them? (Cost; Taste; Not satisfying; Impracticable; Embarrassment; Other reasons)

The following questions were asked of only those who reported being regular users of ECs:

  • 4. How often are you using them? (Several times a day; Several times a week; Several times a month)

  • 5. How long have you been using them like this?

  • 6. Why do you use them? (To cut down; To stop smoking; To smoke where conventional cigarettes are banned; Other reasons)

  • 7. Did EC help you to cut down? (No; Yes)

  • 8. If you compare EC to conventional cigarettes, is their effect on you: (The same; Almost the same; Somewhat weaker; Much weaker; No effect)

Participants who responded to question 1 that they use ECs regularly were classified as regular users unless their response to questions 4 and 5 indicated that they use ECs less than weekly or have been using them weekly for < 1 month. We also analyzed separately daily users, that is, those who reported using ECs daily.

Differences between groups were examined using χ2 or analysis of variance, as appropriate. Where multiple regression modeling was used, variables were entered only if they were significant covariates in univariate analyses. This was an exploratory study with opportunistic sampling and sample size calculations were not performed.

Altogether, the interviewers approached 2,012 smokers, of whom 1,738 (86%) agreed to be interviewed. Table 1 shows the characteristics of the sample. Compared with the national figures,28 the sample included a higher proportion of women (49% compared with the national figure of 37%) but it was similar to the national average in the proportion of smokers who smoke their first cigarette within 60 min of waking up (61% vs 63%).

Table Graphic Jump Location
Table 1 —Sample Characteristics (N = 1,635-1,738)

Sample size varies due to missing data. CPD = cigarettes per day.

Table 2 shows participants’ experience with ECs. One-half of the sample reported trying ECs at least once (50%, 95% CI, 47.7%-52.4%). Of those who tried ECs at least once, 165 reported using them regularly. However, one regular user reported using ECs less than weekly, and six had been using them weekly for < 1 month. We excluded these seven participants from further analyses, leaving 158 regular users (18.3% of those who tried at least ECs once, 95% CI, 15.7%-20.9%). Thirty-eight used ECs several times a week and 120 used them daily, that is, among those who ever tried ECs, 14% (95% CI, 11.6%-16.2%) were daily users. Thirteen regular users (8%) have been using ECs for < 1 month, all of them daily.

Table Graphic Jump Location
Table 2 —Knowledge of and Experience With ECs (N = 1,738)

EC = electronic cigarette.

a 

Seven participants who classified themselves as regular users were using ECs on only a few occasions and were removed from further analyses.

We compared the baseline characteristics of participants who never tried ECs (n = 868) and those who did (n = 863). EC triers were younger than nontriers (31 years vs 36 years old, P < .0001), more likely to be male (54% vs 48%, P < .001); at the time of the survey, they smoked fewer cigarettes per day (CPD) (13 vs 14, P < .005) and were less likely to smoke within the first 5 min of waking (15% vs 19%, P < .001).

The variables previously listed, in which the two groups differed significantly, were entered into a regression model. Age and sex were the only significant independent contributors the model, with the overall model accounting for only 3% of the variance (R2 = 0.03; P < .0001).

Table 3 shows details of EC experience in smokers who tried them. Among smokers who tried ECs at least once, > 60% found the experience as expected or better while 38% were disappointed. As could be expected, almost all regular users had a positive early experience.

Table Graphic Jump Location
Table 3 —First Experience of ECs in Participants Who Tried Them

Data are given as % (No.) See Table 2 legend for expansion of abbreviation.

Table 4 shows that a lack of satisfaction and poor taste were the main reasons smokers who tried ECs gave for not becoming regular users. Those who tried ECs only once were more likely to dislike the taste than those who tried them repeatedly (P < .005). Repeated triers were more likely to be put off by EC impracticability (anecdotally this included factors such as operating the charger and replacing the cartridges) (P < .005).

Table Graphic Jump Location
Table 4 —Reasons for Not Using ECs Regularly

Data are given as % (No.). See Table 2 legend for expansion of abbreviation.

Among the 158 regular users of ECs, mean duration of use was 7.2 months (SD = 8.0; range, 0.25-48 months). There were nine participants who have used ECs for 2 to 4 years. If these nine are removed from the sample, the average duration of EC use was 5.7 months (SD = 4.7; range, 0.25-20 months). The 120 daily users used ECs for a mean of 6.6 months (SD = 7.9; range, 0.25-48 months).

Table 5 shows the most common reason for EC use among regular users. Most use ECs to reduce use of conventional cigarettes. Twenty-eight percent of EC users use them where smoking is not allowed, and 27% use them to quit smoking.

Table Graphic Jump Location
Table 5 —Reasons for Using ECs Among Regular Users

See Table 2 legend for expansion of abbreviation.

Among regular users of ECs, 60% of those who provided the data (n = 154) reported that ECs enabled them to reduce their consumption of conventional cigarettes. These reducers (n = 93) smoked on average 9.7 CPD (SD = 6.5) while those reporting no reduction (n = 61) smoked 13.1 CPD (SD = 7.0) (P < .005). Participants who did not reduce their cigarette consumption include primarily people who use ECs as an aid in situations where smoking is not allowed, rather than means to cut down.

Almost one-half of regular users reported that ECs delivered an effect almost as good as (33%) or equivalent to (16%) that of conventional cigarettes. Thirty-seven percent rated EC effects as somewhat weaker compared with conventional cigarettes, while 14% were regularly using ECs despite rating their effects as substantially weaker than those of conventional cigarettes.

We compared the participants who tried ECs but did not become regular users (n = 705) and those who did become regular users (n = 158). Regular EC users were older (34 years vs 31 years, P < .005), smoked currently fewer CPD (11 vs 13, P < .05), and were more likely to have been pleasantly surprised by ECs (68.5% vs 20%) and less likely to have been disappointed by their early EC experience (2% vs 46%, P < .0001).

All significant discriminators were entered into a regression model. Age and the early impression of ECs were the only significant independent contributors. The model accounted for 19% of the variance (R2 = 0.19, P < .0001).

We reran these analyses excluding the 38 nondaily users. Compared with those who were not regular users (n = 705), daily users (n = 120) were older (34 years vs 31 years, P < .005), less likely to be women (35.8% v 47.2%, P < .05), and were more likely to have been pleasantly surprised by ECs (68.5% v 19.5%) and less likely to have been disappointed by their early EC experience (2% vs 44.6%, P < .0001).

In a regression model including all univariate predictors, age, sex, and the early impression of ECs predicted daily regular use. The model accounted for 18% of the variance (R2 = 0.179, P < .0001).

In this survey of early experience with ECs, 18% of smokers who tried ECs became regular users. Before discussing the implications of these findings, the study limitations need to be acknowledged. First of all, the sample comprised people who still smoked conventional cigarettes and so it excluded those who switched completely to ECs. EC users who cut down on smoking conventional cigarettes dramatically were also likely to be underrepresented as they would be less likely to be seen buying cigarettes or smoking than other smokers. The results, thus, likely underestimate the effects of ECs on smoking reduction and do not capture any effects of ECs in helping people to stop smoking conventional cigarettes altogether. This is unavoidable though because targeting EC users generates a much stronger bias in the opposite direction. Because the key study result is that a larger than expected proportion of smokers move on to use ECs regularly, the fact that an unknown proportion of exclusive EC users was not included strengthens rather than weakens the finding.

The sample was not fully representative of the local population of smokers in that women were overrepresented. As women were less likely to experiment with ECs and, among experimenters, less likely to become daily users, the proportion of smokers who have tried ECs and EC adoption rate (ie, becoming a regular EC user) may have been marginally underestimated. We were unable to examine the role of socioeconomic variables.

The impact of EC use on smoking reduction could not be objectively verified. Although there was no incentive for participants to overreport smoking reduction, and the daily cigarette consumption was significantly lower in those who reported that ECs helped them to cut down than in the rest of the sample, the reduction finding needs be interpreted with caution.

The survey took place in May 2012 and the number of smokers who tried ECs is likely to be higher by the time this article is published. The proportion of smokers who tried ECs (50%) is similar to that reported in a survey from Poland where 43% of teenagers tried ECs in 2011,29 is likely to correspond with the situation in a number of other European countries, and is likely to continue to rise. The relative proportion of smokers who switch at least partly to ECs is, however, likely to remain similar, until ECs improve further. There are examples of this happening, for example, there are disposable EC brands available now that do not require complicated charging, a factor which was cited by a number of smokers who tried ECs as a reason for not using them regularly.

People’s behavior is of course not static, and smokers who did not find ECs satisfactory on one occasion may start using them later, while those who used ECs regularly at one time point may cease their use in future, with cigarette use fluctuating as well. Only prospective longitudinal studies can avoid limitations of cross-sectional studies and account for this dynamic context.

The present data also do not show whether regular EC use is conducive to stopping smoking altogether. People who replace only some of the nicotine from cigarettes with nicotine from ECs are likely to reduce their smoke intake,30 but more data are needed on the degree of health benefit this may convey. In our sample, users of ECs had lower cigarette consumption that nonusers but the difference, although significant, was small. With no data available on cigarette consumption of EC users before they became dual users, this finding is difficult to interpret.

Age may have different effects on EC experimentation and on regular use. Smokers who tried ECs were younger than those who did not try them, but among those who tried ECs, it was the older smokers who became regular user.

The 18% adoption rate is remarkably high, even without the unknown proportion of total adopters who stopped or substantially reduced the use of conventional cigarettes. Together with the finding that most of the regular EC users have been using ECs daily for several months, it suggests that ECs are not just a fad likely to fade away when the novelty wears off, but that the product is developing into a genuine alternative to conventional cigarettes.

Tobacco control efforts need to take this new development into account. A number of concerns have been expressed regarding EC use. Some were not supported by emerging data (eg, safety fears were not substantiated by the available toxicity data, risk of accidental poisoning is comparable to numerous household products which are deemed safe, and so forth12) but others remain. The main concern is that if EC use becomes fashionable and widespread, it could attract people who would otherwise not become nicotine users. ECs are currently not attractive to nonsmokers,25 but fashions change behaviors and this remains a possibility. The key issue would then be the degree of risk such use may pose. Research on switching from cigarettes to snus31,32 and on long-term use of nicotine replacement33,34 shows that nicotine intake from a nonsmoked source carries low or no health risks. Inhalation of propylene glycol and glycerol is considered safe for most people, but inhaling EC vapor affects airways acutely35 and effects of EC use over an extended period of time remain to be evaluated. Another concern is that some novice EC users may switch to conventional cigarettes, though no such case has been documented so far.

A number of countries are considering regulating the product as a medicine. Such regulation is much more demanding and expensive than the consumer protection legislation with which ECs, like other nonmedicinal consumer products, have to comply with currently. ECs are currently produced by small manufacturers. Strict, slow, and expensive regulation is likely to limit the spread of ECs and to stunt their development as each product modification would necessitate new licensing applications. A careful consideration needs to be given to various regulatory proposals and bans to ensure that they do not have an unintended consequence of ensuring the monopoly of deadly conventional cigarettes.

Some 20% of smokers who try the current versions of ECs can be expected to go on to become regular users. The public health community needs to balance the possible benefits and possible risks of a scenario where ECs become attractive enough to start to replace conventional cigarettes on a population scale. Our findings suggest that ECs may indeed have the potential to do so.

Author contributions: Dr Kralikova is the guarantor of the paper, taking responsibility for the integrity of the work as a whole, from inception to published article

Dr Kralikova: contributed to the conception and design of the study and reviewed and critiqued the manuscript

Mr Novak: contributed to the conception and design of the study, coordinated data collection, and reviewed and critiqued the manuscript

Mr West: contributed to the drafting of the manuscript, conducted statistical analyses, and reviewed and critiqued the manuscript

Dr Kmetova: contributed to the conception and design of the study and reviewed and critiqued the manuscript

Prof Hajek: contributed to the conception and design of the study. conducted statistical analyses, drafted the manuscript, and reviewed and critiqued the manuscript

Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Dr Kralikova and Prof Hajek have received research grants from, and provided consultancy to, manufacturers of stop-smoking medications but have no links with any manufacturers of ECs. Messrs Novak and West, and Dr Kmetova have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Role of sponsors: The sponsor had no role in the design of the study, the collection and analysis of the data, or the preparation of the manuscript.

CPD

cigarettes per day

EC

electronic cigarette

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Figures

Tables

Table Graphic Jump Location
Table 1 —Sample Characteristics (N = 1,635-1,738)

Sample size varies due to missing data. CPD = cigarettes per day.

Table Graphic Jump Location
Table 2 —Knowledge of and Experience With ECs (N = 1,738)

EC = electronic cigarette.

a 

Seven participants who classified themselves as regular users were using ECs on only a few occasions and were removed from further analyses.

Table Graphic Jump Location
Table 3 —First Experience of ECs in Participants Who Tried Them

Data are given as % (No.) See Table 2 legend for expansion of abbreviation.

Table Graphic Jump Location
Table 4 —Reasons for Not Using ECs Regularly

Data are given as % (No.). See Table 2 legend for expansion of abbreviation.

Table Graphic Jump Location
Table 5 —Reasons for Using ECs Among Regular Users

See Table 2 legend for expansion of abbreviation.

References

Cahn Z, Siegel M. Electronic cigarettes as a harm reduction strategy for tobacco control: a step forward or a repeat of past mistakes? J Public Health Policy. 2011;32(1):16-31. [CrossRef] [PubMed]
 
Etter J-F, Bullen C. Electronic cigarette: users profile, utilization, satisfaction and perceived efficacy. Addiction. 2011;106(11):2017-2028. [CrossRef] [PubMed]
 
McQueen A, Tower S, Sumner W. Interviews with “vapers”: implications for future research with electronic cigarettes. Nicotine Tob Res. 2011;13(9):860-867. [CrossRef] [PubMed]
 
Yamin CK, Bitton A, Bates DW. E-cigarettes: a rapidly growing internet phenomenon. Ann Intern Med. 2010;153(9):607-609. [CrossRef] [PubMed]
 
Ayers JW, Ribisl KM, Brownstein JS. Tracking the rise in popularity of electronic nicotine delivery systems (electronic cigarettes) using search query surveillance. Am J Prev Med. 2011;40(4):448-453. [CrossRef] [PubMed]
 
Caponnetto P, Campagna D, Papale G, Russo C, Polosa R. The emerging phenomenon of electronic cigarettes. Expert Rev Respir Med. 2012;6(1):63-74. [CrossRef] [PubMed]
 
Borland R. Electronic cigarettes as a method of tobacco control. BMJ. 2011;343:d6269. [CrossRef] [PubMed]
 
Cobb NK, Abrams DB. E-cigarette or drug-delivery device? Regulating novel nicotine products. N Engl J Med. 2011;365(3):193-195. [CrossRef] [PubMed]
 
Etter J-F, Bullen C, Flouris AD, Laugesen M, Eissenberg T. Electronic nicotine delivery systems: a research agenda. Tob Control. 2011;20(3):243-248. [CrossRef] [PubMed]
 
Westenberger B. Evaluation of E-Cigarettes. St. Louis, MO: US Food and Drug Administration; 2009.
 
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