ENDS Adults Who Smoke

Studies, Surveys, Papers, and Case Studies

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Dual Use

2019 Perceived relative harm of using e-cigarettes predicts future product switching among US adult cigarette and e-cigarette dual users.

Compared with those with other perceptions of e‐cigarette harm, dual users who perceived e‐cigarettes as less harmful than cigarettes were more likely to become exclusive e‐cigarette users 1 year later.

2019 Vaping patterns, nicotine dependence and reasons for vaping among American Indian dual users of cigarettes and electronic cigarettes.

...the ten-item Penn State Dependence Index (PSDI) suggested greater dependence on smoking than vaping The most common reasons for vaping were to reduce smoking (79%), enjoyment of flavors (78%), and ability to vape where smoking is not allowed (73%). Perceptions of less harm to others (69%) or to self were the next most common (65%). Fewer than half used ECs to reduce stress, for affordability, or because others used them.

2017 Differences between Dual Users and Switchers Center around Vaping Behavior and Its Experiences Rather than Beliefs and Attitudes

To the extent that dual users substantially lower the number of cigarettes, they will reduce health risks from smoking. However, from a medical point of view, exclusive vaping is preferable to dual use; Differences between dual users and switchers center around variables proximal to the vaping behavior and its experienced effects rather than hinging on more general vaping-related beliefs and attitudes. After e-cig initiation, dual users decreased tobacco consumption by 82% and were low-to-moderately cigarette dependent. The two groups (dual users and switchers) reported mostly using a flavor other than tobacco.

Economic Impact

2019 The Impact of Electronic Cigarettes on Cigarette Smoking By Americans and Its Health and Economic Implications

In this study, we examined the growing use of electronic cigarettes and its implications. The wide use of e-cigarettes is a very recent development, and issues regarding their long-term effects and significance cannot be fully analyzed at this time. Using CDC and other data covering the last decade, however, we examined the relationship between the recent sharp increase in e-cigarette use among Americans and the contemporaneous acceleration in the declining rate of cigarette smoking. We found that the sharp increase in e-cigarette use across many groups can explain as much as 70 percent of the accelerating decline in smoking rates. We also found no reasonable evidential basis for concerns that e-cigarettes are a gateway to cigarette smoking. We further found that e-cigarettes are highly effective in helping people stop smoking cigarettes. Finally, we analyzed the impact of the sharp increase in e-cigarette use and the accelerating decline in cigarette smoking on healthcare costs and economic productivity. We found that while e-cigarette users incur lower healthcare costs than cigarette smokers or ex-smokers, the longer lifespans of e-cigarette users and ex-smokers who used e-cigarettes to quit smoking result in higher lifetime healthcare costs. However, we also found that the value of the additional years of life associated with using e-cigarettes instead of smoking is much greater than the additional healthcare costs. Lastly, we found that the increase in e-cigarette use and the associated reduction in smoking rates results in large productivity benefits, mainly from lower rates of illness.

2019: Cost‐effectiveness of e‐cigarettes compared with nicotine replacement therapy in stop smoking services in England (TEC study): a randomized controlled trial

Using e‐cigarettes as a smoking cessation aid with standard behavioural (behavioral) support in stop‐smoking services in England is likely to be more cost‐effective than using nicotine replacement therapy in the same setting.

2019: Expenditure on smoking and alternative nicotine delivery products: a population survey in England

Conclusion: “In England, expenditure among e‐cigarette and nicotine replacement therapy users is approximately one‐third of the expenditure of smokers. The average smoker may save an estimated £15.06 per week by switching completely to e‐cigarettes or £13.04 per week by switching to nicotine replacement therapy, although this is likely to differ according to individual usage patterns.”

2018: Behavioral Economic Purchase Tasks to Estimate Demand for Novel Nicotine/tobacco Products and Prospectively Predict Future Use: Evidence From The Netherlands

Smokers valued FMCs [factory made cigarettes] more than ECs [electronic cigarettes] or VLNCs, [very low nicotine cigarettes] and FMCs were less sensitive to price increases. Demand indices predicted use of commercially available products over a 15 month period. To serve as viable substitutes for FMCs, ECs and VLNCs will need to be priced lower than FMCs.

Flavors

2020: Intended and Unintended Effects of Banning Menthol Cigarettes

Menthol bans significantly increased non-menthol cigarette smoking among youths, resulting in no overall net change in youth smoking rates. Menthol bans shifted smokers’ cigarette purchases away from grocery stores and gas stations to First Nations reserves (where the menthol bans do not bind).

2020: Associations of Flavored e-Cigarette Uptake With Subsequent Smoking Initiation and Cessation

Relative to vaping tobacco flavors, vaping nontobacco-flavored e-cigarettes was not associated with increased youth smoking initiation but was associated with an increase in the odds of adult smoking cessation.

2020: Association of vaping‐related lung injuries with rates of e‐cigarette and cannabis use across US states

At the same time, policymakers should proceed with caution when considering bans on flavored e‐liquids: restricting legal sales may push some vapers towards illicit sources, user‐modified e‐liquids (e.g. to add flavoring) or even conventional cigarette use. Given EVALI’s potential lethality and a myriad of work suggesting that conventional cigarette use is probably far more dangerous than vaping nicotine, these outcomes could be disastrous for public health.

2020: Reported patterns of vaping to support long-term abstinence from smoking: a cross-sectional survey of a convenience sample of vapers

Most attempts at smoking cessation result in relapse, and smokers generally make multiple quit attempts before succeeding. Qualitative research suggests e-cigarettes can meet many of the needs of ex-smokers by substituting physical, psychological, social, cultural and identity-related aspects of tobacco addiction. According to a time-series analysis of data from the Smoking Toolkit study, in which repeated cross-sectional surveys are conducted with a representative sample of households in England, increasing prevalence of e-cigarette use in current smokers was predictive of higher success rates of quit attempts. Most participants were self-reported long-term abstinent smokers (86.3%). Those who start on a low self-reported nicotine e-liquid concentration (strength) will be more likely to relapse to tobacco smoking than those starting on a higher nicotine e-liquid, after controlling for cigarettes per day (CPD) before cessation. Results suggest a change in flavor choices over the course of vaping initiation and uptake. There was a reduction in the proportion of people using a tobacco flavor, and increase in the proportion using a fruit/sweet/food flavor, from initial to current flavor choice According to the 2017 ASH-A survey, among current users, fruit flavors were the most popular.

2020: The impact of a comprehensive tobacco product flavor ban in San Francisco among young adults

A sample of San Francisco residents aged 18–34 who previously used tobacco products were surveyed about their tobacco use both before and after the ban. Among the 18–24 age group, there was a significant increase in cigarette smoking. Cigarette smoking increased among 25–34 years old. Banning flavors in e-cigarettes would prompt e-cigarette use cessation but may also push some e-cigarette users to turn to cigarette smoking and could prompt some youth to initiate into smoking instead of e-cigarette use. The proportions of e-cigarettes, cigarettes, and cigars obtained over the internet increased after the ban, and the proportions obtained from retailers outside of San Francisco also increased overall.

2019: Changes in Flavor Preference in a Cohort of Long-Term Electronic Cigarette Users

...or may reflect a user’s own experience that using non–tobacco-related flavors may constitute a flavor that they can happily use and make them less likely to return to cigarette smoking. Our results regarding anticipated reactions to FDA e-cigarette flavor regulation suggest complexities such that the benefits and risks of flavor ban need to be carefully evaluated. However, a majority anticipated that they would personally attempt to circumvent potential FDA regulations of e-cigarettes by obtaining e-cigarette flavors from various illicit sources (e.g., Internet orders from foreign countries) or even self-making flavors. The use of flavoring agents purchased from unregulated sources could lead to additional unanticipated toxicities. It is also concerning that some established e-cigarette users believed that they would return to cigarette smoking if nontobacco e-cigarette flavors were banned. Thus, for adult e-cigarette users who use certain flavors to facilitate smoking cessation or reduction, banning all nontobacco flavors could precipitate relapse to smoking.

2019: The role of flavors in vaping initiation and satisfaction among U.S. adults

In terms of cigarette smoking status, 35.6% of respondents were past smokers, and 38.0% were current smokers. Most common reasons for vaping initiation were as an alternative to cigarettes (43.7%) and because respondents viewed e-cigarettes as less harmful than other tobacco products (31.2%). Flavor was the third most commonly reported reason. Satisfaction among those who bought flavored e-liquid was higher than those who did not buy flavored e-liquid.

2018 Patterns of flavored e-cigarette use among adults vapers in the United States: an internet survey

In conclusion, this cross-sectional study of a very large sample of adult US e-cigarette users, most of which were former smokers, identified the importance of non-tobacco flavors in e-cigarette use initiation and sustained use, and their contribution to smoking cessation and relapse prevention. This information should be considered by regulators in order to avoid unintentional adverse effects of over-restrictive regulation on e-cigarette flavors.

2018: Changing patterns of first e-cigarette flavor used and current flavors used by 20,836 adult frequent e-cigarette users in the USA

Conclusion: Adult frequent e-cigarette users in the USA who have completely switched from smoking cigarettes to using e-cigarettes are increasingly likely to have initiated e-cigarette use with non-tobacco flavors and to have transitioned from tobacco to non-tobacco flavors over time. Restricting access to non-tobacco e-cigarette flavors may discourage smokers from attempting to switch to e-cigarettes.

2018: Should flavours be banned in cigarettes and e-cigarettes? Evidence on adult smokers and recent quitters from a discrete choice experiment

A ban on flavoured e-cigarettes alone would likely increase the choice of cigarettes in smokers, arguably the more harmful way of obtaining nicotine

2016: Cigarette smoking and electronic cigarette vaping patterns as a function of e-cigarette flavourings

The findings suggest that adoption of e-cigarettes in smokers may influence smoking rates of people who smoke. E-cigarette vaping rates are influenced by flavourings. These findings may have implications for the utility of e-cigarettes as a nicotine replacement device and for the regulation of flavourings in e-cigarettes for harm reduction.

2015: The Impact of Flavor Descriptors on Nonsmoking Teens’ and Adult Smokers’ Interest in Electronic Cigarettes

Nonsmoking teens’ interest in e-cigarettes was very low. Adult smokers’ interest was significantly higher overall and for each flavor. Teen interest did not vary by flavor, but adult interest did. Past-30-day adult e-cigarette users had the greatest interest in e-cigarettes, and their interest was most affected by flavor. Nonsmoking teens who had never tried e-cigarettes had the lowest interest, followed by adults who had never tried e-cigarettes

2015: Preferred Flavors and Reasons for E-cigarette Use and Discontinued Use Among Never, Current, and Former Smokers

Never users had significantly lower prevalence of use of alcohol, marijuana, and other tobacco products (take less risks) Among current e-cigarette users, the most commonly used flavor was fruit flavors (67%) The most commonly reported reasons for e-cigarette use were “they might be less harmful than cigarettes” (77%); “they don’t smell” (77%); “they help people quit smoking” (66%); and “they cost less than other forms of tobacco” (62%); these reasons were more frequently endorsed by former smokers. Over 90% of former cigarette smokers who were current e-cigarette users reported using e-cigarettes to quit smoking. Over half of never smokers who are former e-cigarette users said they did not recently use e-cigarettes because they “just don’t think about it”, possibly indicating that addiction did not play a role in their use.

2013: Impact of Flavour Variability on Electronic Cigarette Use Experience: An Internet Survey

4,618 participants were included in the analysis, with 4,515 reporting current smoking status (current vs. former smokers). More than 90% were former smokers. The mean age was 40 years At the time of participation, most commonly used flavours were fruits, followed by sweets. Most participants (68.3%) were switching between flavours on a daily basis or within the day, with former smokers switching more frequently. More than half of the study sample mentioned that they like the variety of flavours and that the taste gets blunt from long-term use of the same flavour. The average score for importance of flavours variability in reducing or quitting smoking was 4 (“very important”). Finally, the majority of participants stated that restricting variability of flavours would make the EC experience less enjoyable while almost half of them answered that it would increase craving for tobacco cigarettes and would make reducing or completely substituting smoking less likely. The results of this survey indicate that EC liquid flavourings play a major role in the overall experience of dedicated users and support the hypothesis that they are important contributors in reducing or eliminating smoking consumption.

Nicotine Levels

2020: Might limiting liquid nicotine concentration result in more toxic electronic cigarette aerosols?

Thus, if users seek a given nicotine yield, regulatory limits on nicotine concentration may have the unintended consequence of increasing exposure to aerosol and respiratory toxicants. This outcome demonstrates that attempting to control ECIG nicotine yield by regulating one factor at a time may have unintended health effects and highlights the need to consider multiple factors and outcomes simultaneously when designing regulations.

2020: Reported patterns of vaping to support long-term abstinence from smoking: a cross-sectional survey of a convenience sample of vapers

Most attempts at smoking cessation result in relapse, and smokers generally make multiple quit attempts before succeeding. Qualitative research suggests e-cigarettes can meet many of the needs of ex-smokers by substituting physical, psychological, social, cultural and identity-related aspects of tobacco addiction. According to a time-series analysis of data from the Smoking Toolkit study, in which repeated cross-sectional surveys are conducted with a representative sample of households in England, increasing prevalence of e-cigarette use in current smokers was predictive of higher success rates of quit attempts. Most participants were self-reported long-term abstinent smokers (86.3%). Those who start on a low self-reported nicotine e-liquid concentration (strength) will be more likely to relapse to tobacco smoking than those starting on a higher nicotine e-liquid, after controlling for cigarettes per day (CPD) before cessation. Results suggest a change in flavor choices over the course of vaping initiation and uptake. There was a reduction in the proportion of people using a tobacco flavor, and increase in the proportion using a fruit/sweet/food flavor, from initial to current flavor choice According to the 2017 ASH-A survey, among current users, fruit flavors were the most popular.

2016: Protocol proposal for, and evaluation of, consistency in nicotine delivery from the liquid to the aerosol of electronic cigarettes atomizers: regulatory implications

Electronic cigarettes that use tank‐type atomizers appear to deliver nicotine in more consistent quantities (within the acceptable limits for medicinal nebulizers and similar to the nicotine inhaler) than electronic cigarettes that use cartomizers. The protocol for testing nicotine delivery consistency described in this paper could be used effectively for regulatory purposes.

2013: Evaluating Nicotine Levels Selection and Patterns of Electronic Cigarette use in a Group of “Vapers” Who Had Achieved Complete Substitution of Smoking

Nicotine levels appear to play an important role in achieving and maintaining smoking cessation in the group of motivated subjects studied. High nicotine-containing liquids were used while few mild and temporary side effects were reported. Proposals about regulation should consider the pragmatic use patterns of ECs, especially in consumers who have completely substituted smoking. 42% of participants reported quitting smoking during the first month of EC use. Liquids with nicotine concentration >15 mg/mL were used by 74% of users at initiation of EC use, while 16.2% had to increase the initial nicotine levels in order to achieve complete smoking abstinence. 64.9% reported that from the time of smoking cessation to the time of the interview (8 months median duration of EC use) they reduced the nicotine concentration they were consuming. The vast majority of participants reported better exercise capacity and improved olfactory and gustatory senses. Perceived EC dependency was significantly lower compared to smoking.

2013: Nicotine levels in electronic cigarettes.

E-cigarettes (ECs) generate vapor that contains nicotine, but EC brands and models differ in their efficacy and consistency of nicotine vaporization. In ECs, which vaporize nicotine effectively, the amount inhaled from 15 puffs is lower compared with smoking a conventional cigarette.

Quitting Smoking: E-cigarette vs. NRT OR E-cigarette with NRT

2020: QuitNic: A pilot randomised controlled trial comparing nicotine vaping products with nicotine replacement therapy for smoking cessation following residential detoxification

This pilot study showed that smoking cessation support involving options for nicotine replacement and Quitline-delivered cognitive behavioural counselling is attractive to people after they have been discharged from SUD (Substance Use Disorder) treatment. Retention was 63% at 6-weeks and 50% at 12-weeks. At 12-weeks, 68% of the NRT group reported using combination NRT while 96% of the NVP group used the device. Acceptability ratings for the products were high in both groups. At 12-weeks, 14% of the NVP group and 18% of the NRT group reported not smoking at all in the last 7 days. Mean CPD (Cigarettes Per Day) among continued smokers decreased significantly between baseline to 12-weeks in both groups; from 19.91 to 4.72 for the NVP group (p<0.001) and from 20.88 to 5.52 in the NRT group (p<0.001). Cravings and withdrawal symptoms significantly decreased for both groups.

2020: Effectiveness of Electronic Cigarettes in Smoking Cessation: a Systematic Review and Meta-Analysis

Our results suggest that nicotine-ECs may be more effective in smoking cessation when compared to placebo ECs or NRT.

2019: E-cigarettes compared with nicotine replacement therapy within the UK Stop Smoking Services: the TEC RCT

The primary outcome was CO-validated sustained abstinence rates at 52 weeks. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. The 1-year quit rate was 9.9% in the NRT arm and 18.0% in the e-cigarette arm. The e-cigarette arm had significantly higher validated quit rates at all time points. Participants in the e-cigarette arm showed significantly better adherence and experienced fewer urges to smoke throughout the initial 4 weeks of their quit attempt than those in the NRT arm, and gave their allocated product more favourable ratings. They were also more likely to be still using their allocated product at 1 year Participants assigned to e-cigarettes reported significantly less coughing and phlegm at 1 year than those assigned to NRT A detailed economic analysis confirmed that, because e-cigarettes incur lower NHS costs than NRT and generate a higher quit rate, e-cigarette use is more cost-effective.

2019: Cost‐effectiveness of e‐cigarettes compared with nicotine replacement therapy in stop smoking services in England (TEC study): a randomized controlled trial

Using e‐cigarettes as a smoking cessation aid with standard behavioural support in stop‐smoking services in England is likely to be more cost‐effective than using nicotine replacement therapy in the same setting.

2019: Effect of Electronic Cigarettes on Smoking Reduction and Cessation in Korean Male Smokers: A Randomized Controlled Study

In our study, the effect of e-cigarettes on smoking cessation was similar compared with that of nicotine gum, a well-documented NRT. In addition, e-cigarettes were well tolerated by the study population. Therefore, the use of e-cigarettes as an NRT may be considered for smoking-cessation purposes.

2019: A Randomized Trial of E-Cigarettes versus Nicotine-Replacement Therapy

Results: A total of 886 participants underwent randomization. The 1-year abstinence rate was 18.0% in the e-cigarette group, as compared with 9.9% in the nicotine-replacement group (relative risk, 1.83; 95% confidence interval [CI], 1.30 to 2.58; P<0.001). Among participants with 1-year abstinence, those in the e-cigarette group were more likely than those in the nicotine-replacement group to use their assigned product at 52 weeks (80% [63 of 79 participants] vs. 9% [4 of 44 participants]). Overall, throat or mouth irritation was reported more frequently in the e-cigarette group (65.3%, vs. 51.2% in the nicotine-replacement group) and nausea more frequently in the nicotine-replacement group (37.9%, vs. 31.3% in the e-cigarette group). The e-cigarette group reported greater declines in the incidence of cough and phlegm production from baseline to 52 weeks than did the nicotine-replacement group (relative risk for cough, 0.8; 95% CI, 0.6 to 0.9; relative risk for phlegm, 0.7; 95% CI, 0.6 to 0.9). There were no significant between-group differences in the incidence of wheezing or shortness of breath. Conclusion: E-cigarettes were more effective for smoking cessation than nicotine-replacement therapy, when both products were accompanied by behavioral support.

2019: Nicotine patches used in combination with e-cigarettes (with and without nicotine) for smoking cessation: a pragmatic, randomised trial

In summary, when looking at continuous abstinence from smoking, provision of patches plus a nicotine e-cigarette resulted in three to seven more smokers per 100 quitting long-term (depending on the analyses done) than with patches plus a nicotine-free e-cigarette. The smaller than anticipated sample size meant the study was not sensitive enough to pick up a definitive finding for the second comparison, although analyses suggest combination nicotine therapy—ie, use of a slow release nicotine patch, together with a faster-acting oral nicotine product (in this case a nicotine e-cigarette)—could result in five to ten more smokers per 100 quitting long-term than with monotherapy (ie, nicotine patches alone). Our findings are consistent with the current findings of the Cochrane review of e-cigarettes for smoking cessation and contribute to the growing body of evidence from randomised trials on the efficacy, effectiveness and safety of e-cigarettes for smoking cessation.

2018: American Cancer Society Position Statement on Electronic Cigarettes

Based on currently available evidence, using current generation e-cigarettes is less harmful than smoking cigarettes, but the health effects of long-term use are not known. The ACS has always supported any smoker who is considering quitting, no matter what approach they use; there is nothing more important that they can do for their health. Some smokers, despite firm clinician advice, will not attempt to quit smoking cigarettes and will not use FDA approved cessation medications. These individuals should be encouraged to switch to the least harmful form of tobacco product possible; switching to the exclusive use of e-cigarettes is preferable to continuing to smoke combustible products.

2018: Discussions between health professionals and smokers about nicotine vaping products: results from the 2016 ITC Four Country Smoking and Vaping Survey

Despite the need for more evidence on their efficacy and long‐term safety, NVPs are now a more popular method for cessation than licensed NRT and prescription stop‐smoking medications in many countries. In light of this, HPs should be prepared to provide balanced information about NVPs, particularly to smokers who are unable to stop smoking with approved cessation therapies, and for those who are requesting guidance regarding NVPs as a smoking cessation aid Overall, the results from this study have shown that discussions between smokers and HPs about both quitting smoking, and the possible role NVPs could play as a cessation aid, were infrequent in the four countries in 2016. This may represent a lost opportunity for encouraging quitting smoking by providing a potentially attractive option to help smokers to quit.

2016: E-cigarettes: a developing public health consensus

From: Public Health England, Action on Smoking and Health, Association of Directors of Public Health, British Lung Foundation, Cancer Research UK, Faculty of Public Health, Fresh North East, Healthier Futures, Public Health Action, Royal College of Physicians, Royal Society for Public Health, UK Centre for Tobacco and Alcohol Studies, UK Health Forum

We all agree that e-cigarettes are significantly less harmful than smoking. One in two lifelong smokers dies from their addiction. All the evidence suggests that the health risks posed by e-cigarettes are relatively small by comparison but we must continue to study the long-term effects. And yet, millions of smokers have the impression that e-cigarettes are at least as harmful as tobacco The public health opportunity is in helping smokers to quit, so we may encourage smokers to try vaping but we certainly encourage vapers to stop smoking tobacco completely. We know that e-cigarettes are the most popular quitting tool in the country with more than 10 times as many people using them than using local stop smoking services The current national evidence is that in the UK regular e-cigarette among youth use is almost exclusively confined to those young people who have already smoked, and youth smoking prevalence is continuing to fall We should not forget what is important here. We know that smoking is the number one killer in England and we have a public health responsibility to provide smokers with the information and the tools to help them quit smoking completely and forever.

2014: Real-world effectiveness of e-cigarettes when used to aid smoking cessation: a cross-sectional population study

Conclusion: “Among smokers who have attempted to stop without professional support, those who use e-cigarettes are more likely to report continued abstinence than those who used a licensed NRT product bought over-the-counter or no aid to cessation. This difference persists after adjusting for a range of smoker characteristics such as nicotine dependence.”

2014: E-cigarette versus nicotine inhaler: comparing the perceptions and experiences of inhaled nicotine devices

Related Article: E-Cigarettes vs. Nicotine Inhalers “In conclusion, during this brief trial, the e-cigarette was found to be more acceptable, provided more satisfaction and rewards, and had higher perceived benefit than the nicotine inhaler. These findings may explain why the e-cigarette has become popular among smokers while the inhaler has not achieved the same favorability. Based on this difference, e-cigarettes could have the potential to become “tobacco cigarette substitutes,” owing to their high acceptance and perceived effectiveness. While toxicants have been identified in e-cigarettes, they are present at orders of magnitude lower than tobacco cigarettes. As such, e-cigarettes may hold value as a harm reduction strategy among those unwilling or unable to quit. However, given the large variation in the market with respect to brands, more data are needed to demonstrate their efficacy and safety, and to allow physicians to more appropriately inform their patients about these products.”

2013: Electronic cigarettes for smoking cessation: a randomised controlled trial

657 people were randomised (289 to nicotine e-cigarettes, 295 to patches, and 73 to placebo e-cigarettes) and were included in the intention-to-treat analysis. At 6 months, verified abstinence was 7·3% (21 of 289) with nicotine e-cigarettes, 5·8% (17 of 295) with patches, and 4·1% (three of 73) with placebo e-cigarettes

2013: A fresh look at tobacco harm reduction: the case for the electronic cigarette

Smokers of any age can reap substantial health benefits by quitting. In fact, no other single public health effort is likely to achieve a benefit comparable to large-scale smoking cessation.

E-cigs might be the most promising product for tobacco harm reduction to date, because, besides delivering nicotine vapour without the combustion products that are responsible for nearly all of smoking’s damaging effect, they also replace some of the rituals associated with smoking behaviour.

Nicotine’s beneficial effects include correcting problems with concentration, attention and memory, as well as improving symptoms of mood impairments. Keeping such disabilities at bay right now can be much stronger motivation to continue using nicotine than any threats of diseases that may strike years and years in the future. Nicotine’s beneficial effects can be controlled, and the detrimental effects of the smoky delivery system can be attenuated, by providing the drug via less hazardous delivery systems. Although more research is needed, e-cigs appear to be effective cigarette substitutes for inveterate smokers, and the health improvements enjoyed by switchers do not differ from those enjoyed by tobacco/nicotine abstainers.

2013: Electronic cigarettes and vaping: a new challenge in clinical medicine and public health. A literature review

When compared to the harmful effects of smoking, these studies suggest that vaping could be used as a possible “harm reduction” tool. There is evidence supporting e-cigarettes as an aide for smoking cessation, at least as successful as currently available FDA-approved NRTs.

2011: Successful smoking cessation with electronic cigarettes in smokers with a documented history of recurring relapses: a case series

The most important message from this case series is that these smokers, with a documented history of recurring relapses, were able to quit smoking and to remain abstinent for at least six months after taking up an electronic cigarette.

Quitting Smoking / Preventing Relapse (No comparison to other methods)

2020: Tobacco harm reduction in the 21st century (PDF 16 pages) In conclusion, to reduce smoking and to save millions of lives, tobacco harm reduction in the form of cigarette substitution with low-risk products appears to be a promising path. These products, although not completely risk-free, offer an alternative to quit or die. In consideration of the available evidence, advice to tobacco smokers should include trying substitute products. The obvious fact so often overlooked is that smoking is rewarding and people like to do it. Giving smokers an alternative with efficient nicotine delivery means that they might prefer one of these products over cigarettes.

2019: Association Between Electronic Cigarette Use and Smoking Reduction in France (Must pay to view full article or PDF) Findings This cohort study found that, among daily smokers in France, regular (daily) electronic cigarette use is associated with a significantly higher decrease in the number of cigarettes smoked per day as well as an increase in smoking cessation attempts. However, among former smokers, electronic cigarette use is associated with an increase in the rate of smoking relapse. NOTE: Article that covers above study - Adults who vape are more likely to quit cigarettes, study finds “The study did find that the heightened risk of relapse disappeared in those who quit smoking more recently, which the researchers said may be due to improved e-cigarette technology.” “For example, the study as a whole considered anybody who quit smoking from 2010 onward and found that, in that sample, vaping increased the risk of relapse. But when researchers only considered people who quit cigarettes as of 2013, former smokers were not more likely to relapse if they vaped.” “The researchers noted in their study that "measures of plasma nicotine levels have shown that, compared with older models of [e-cigarettes], the new generation delivers higher levels of nicotine to the bloodstream," which may make them more satisfying.” “Other "technical improvements in [e-cigarettes] over time," they said, may also explain why people who recently quit smoking and switched to e-cigarettes were less likely to relapse than those who quit earlier.”

2019: Association of prevalence of electronic cigarette use with smoking cessation and cigarette consumption in England: a time–series analysis between 2007 and 2017 (PDF 14 pages) The increase in prevalence of e‐cigarette use by smokers in England has been positively associated with an increase in success rates of quit attempts and overall quit rates

2019 Electronic Cigarette Use and Cigarette Abstinence Over 2 Years Among U.S. Smokers in the Population Assessment of Tobacco and Health Study In this nationally representative longitudinal cohort study of US adult cigarette smokers, daily e-cigarette use, compared to no e-cigarette use, was associated with a 77% increased odds of prolonged cigarette smoking abstinence over the subsequent 2 years. Regular use of e-cigarettes may help some smokers to stop smoking combustible cigarettes. Article: Daily e-cigarette use may help smokers quit regular cigarettes

2019 Article: Adults who vape are more likely to quit cigarettes, study finds “The study did find that the heightened risk of relapse disappeared in those who quit smoking more recently, which the researchers said may be due to improved e-cigarette technology.” “For example, the study as a whole considered anybody who quit smoking from 2010 onward and found that, in that sample, vaping increased the risk of relapse. But when researchers only considered people who quit cigarettes as of 2013, former smokers were not more likely to relapse if they vaped.” “The researchers noted in their study that "measures of plasma nicotine levels have shown that, compared with older models of [e-cigarettes], the new generation delivers higher levels of nicotine to the bloodstream," which may make them more satisfying.” “Other "technical improvements in [e-cigarettes] over time," they said, may also explain why people who recently quit smoking and switched to e-cigarettes were less likely to relapse than those who quit earlier.”

2017: Predicting Short-Term Uptake of Electronic Cigarettes: Effects of Nicotine, Subjective Effects, and Simulated Demand (Must pay to view PDF) Mean cigarettes per day decreased by 37% when e-cigarettes were available relative to baseline. Nicotine-containing cartridges were associated with greater use and craving reduction than 0 mg. Alleviation of withdrawal symptoms and taste and enjoyment factors predicted e-cigarette use.

2017: Cohort study of electronic cigarette use: effectiveness and safety at 24 months (PDF 9 pages) Of the e-cigarette users, 61.1% remained abstinent from tobacco (while 23.1% and 26.0% of tobacco-only smokers and dual users achieved tobacco abstinence).

2016: Patterns of Electronic Cigarette Use Among Adults in the United States (PDF 5 pages) Results: Current e-cigarette use is extremely low among never cigarette smokers (0.4%) and former smokers who quit cigarettes 4 or more years ago (0.8%). Although e-cigarette experimentation is most common among current cigarette smokers and young adults, daily use is highest among former smokers who quit in the past year (13.0%) and older adults. Compared to daily cigarette smokers, recently quit smokers were more than four times as likely to be daily users of e-cigarettes ( AOR : 4.33 [95% CI: 3.08–6.09]). Conclusion: Extremely low e-cigarette use among never-smokers and longer term former smokers suggest that e-cigarettes neither promote widespread initiation nor relapse among adults. Recognition of the heterogeneity of smokers, including the time since quitting, is critical to draw accurate conclusions about patterns of e-cigarette use at the population level and its potential for public health benefit or harm.

2016: Electronic cigarette use in the European Union: analysis of a representative sample of 27 460 Europeans from 28 countries(Must pay to view PDF / full paper) E‐cigarette use in the European Union appears to be largely confined to current or former smokers, while current use and nicotine use by people who have never smoked is rare. More than one‐third of current e‐cigarette users polled reported smoking cessation and reduction.

2015: E-Cigarettes and Smoking Cessation: Evidence from a Systematic Review and Meta-Analysis

Conclusions: “This systematic review and meta-analyses assessed the findings of six studies which reported smoking cessation after using e-cigarettes. We found an association between nicotine-enriched e-cigarette use and smoking cessation, suggesting that the devices may be an effective alternative smoking cessation method. We also found that use of e-cigarettes was also associated with a reduction in the number of cigarettes used, suggesting they may also have a role in tobacco harm reduction programs. To our knowledge, this is the most comprehensive evidence to date on this issue, and while there are a number of important implications for further research, these findings provide timely information to inform regulatory strategies.”

2015: A Longitudinal Study of Electronic Cigarette Use Among a Population-Based Sample of Adult Smokers: Association With Smoking Cessation and Motivation to Quit

Results: At follow-up, 23% were intensive users, 29% intermittent users, 18% had used once or twice, and 30% had not tried e-cigarettes. Logistic regression controlling for demographics and tobacco dependence indicated that intensive users of e-cigarettes were 6 times more likely than non-users/triers to report that they quit smoking (OR: 6.07, 95% CI = 1.11, 33.2). No such relationship was seen for intermittent users. There was a negative association between intermittent e-cigarette use and 1 of 2 indicators of motivation to quit at follow-up. Conclusion: Daily use of electronic cigarettes for at least 1 month is strongly associated with quitting smoking at follow-up. Further investigation of the underlying reasons for intensive versus intermittent use will help shed light on the mechanisms underlying the associations between e-cigarette use, motivation to quit, and smoking cessation.

2015: Associations Between E-Cigarette Type, Frequency of Use, and Quitting Smoking: Findings From a Longitudinal Online Panel Survey in Great Britain

Conclusion: Whether e-cigarette use is associated with quitting depends on type and frequency of use. Compared with respondents not using e-cigarettes, daily tank users were more likely, and non-daily cigalike users were less likely, to have quit. Tanks were more likely to be used by older respondents and respondents with lower education.

2015: Electronic Cigarettes Efficacy and Safety at 12 Months: Cohort Study (PDF 14 pages) Results: Follow-up data were available for 236 e-smokers, 491 tobacco smokers, and 232 dual smokers (overall response rate 70.8%). All e-smokers were tobacco ex-smokers. At 12 months, 61.9% of the e-smokers were still abstinent from tobacco smoking; 20.6% of the tobacco smokers and 22.0% of the dual smokers achieved tobacco abstinence. Adjusting for potential confounders, tobacco smoking abstinence or cessation remained significantly more likely among e-smokers...

2014: Effectiveness of the Electronic Cigarette: An Eight-Week Flemish Study with Six-Month Follow-up on Smoking Reduction, Craving and Experienced Benefits and Complaints

When people, ready to switch to an e-cig, are severely restricted in terms of accessibility of nicotine-containing e-liquids, the success of e-cigs may be endangered. For the e-cig to be and remain successful, it is important that people have easy access to nicotine containing e-liquids. Conclusion: “In a series of controlled lab sessions with e-cig-naïve tobacco smokers, second-generation e-cigs were shown to be immediately and highly effective in reducing abstinence-induced cigarette craving and withdrawal symptoms, while not resulting in increases in eCO. Ad libitum use of e-cigs—in between and until six months after the lab sessions—resulted in remarkable reductions in or (biologically confirmed) complete abstinence from tobacco smoking in almost half of the participants who had no intention to quit smoking. [highlighting added] Eight months after the start of the study 21% of all participants were completely abstinent from tobacco cigarettes. Similar reduction/cessation rates were obtained with guided versus non-guided switching to e-cigs. Part of the observed efficacy of e-cigs in this study may be related to the fact that they allowed to maintain relatively high blood nicotine levels and showed an excellent experienced benefits/complaints ratio, especially in comparison with continued tobacco smoking”... E-cigarette is an attractive long-term alternative and safer source of nicotine to conventional cigarette. Since their invention in 2003, there has been constant innovation and development of more efficient and appealing products. Here we show for the first time that second generation PVs can substantially decrease cigarette consumption without causing significant side effects in smokers not intending to quit. Moreover, overall participants’ perception and acceptance of these products was very good, in particular for those who quit or reduced smoking. Compared to our earlier work with first generation “cig-alikes”, technical problems and difficulties in use familiarization with second generation PVs were negligible. Improved products reliability and attractiveness might have contributed to the very low number of study failures and lost to follow-up and high success rates thus confirming the notion that these products are attractive substitutes for conventional cigarettes. Although large and carefully conducted RCTs will be required to confirm these preliminary encouraging observations, the notion that second generation PVs can substantially decrease cigarette consumption in smokers not intending to quit should be taken into consideration by regulatory authorities seeking to adopt proportional measures for the vapour category

2014: Success rates with nicotine personal vaporizers: a prospective 6-month pilot study of smokers not intending to quit

Complete tobacco cessation is the best outcome for smokers, but the powerful addictive qualities of nicotine and of the ritualistic behavior of smoking create a huge hurdle, even for those with a strong desire to quit. Tobacco harm reduction (THR), the substitution of low-risk nicotine products for cigarette smoking, is a realistic strategy for smokers who have difficulty quitting. E-cigarettes are the newest and most promising products for THR. This approach has been recently exploited to reduce or reverse the burden of harm in smokers with mental health disorders and chronic airway disease.

2014: Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers

The main results of this survey indicate that ECs may be an effective substitute for smoking even in highly dependent subjects who are heavy smokers. Significant benefits are experienced by these people in physiologic functions and in some disease conditions, with former smokers (those who completely substituted smoking with EC use) being more likely to report such beneficial effects.

Both former and current smokers initiated EC use with high nicotine-containing liquids. More than one-fifth of the population initiated use with more than 20 mg/mL nicotine concentration, with higher prevalence in former smokers, supporting the hypothesis that nicotine plays an important role in the success of ECs as smoking substitutes [4,16]. This can be attributed to the lower nicotine absorption from EC use compared to smoking [13,17,18]. Such repeated observations should be taken into consideration by the regulatory authorities. The most important reasons for participants to initiate ECs were to reduce or completely quit smoking and to reduce exposure of family members to second-hand smoking. It seems that these subjects are well-informed about the adverse health effects of smoking and are willing to try an alternative product which they consider less harmful. In conclusion, in this large sample of dedicated EC users, it seems that ECs are used as long-term substitutes to smoking. They can be effective even in subjects who are highly dependent on smoking and are heavy smokers. Mild temporary side-effects and significant benefits are reported by this population. Motivation for using ECs comes from their expected less harmful potential compared to smoking.

2014: Reasons for quitting cigarette smoking and electronic cigarette use for cessation help

Thus, this may be the first study to suggest that smokers who want to quit smoking for immediate, extrinsic rewards may be attracted to use e-cigarettes to stop smoking cigarettes than smokers who want to quit smoking for intrinsic reasons such as health concerns. In conclusion, e-cigarettes appear to provide a “smoking” alternative to a section of cigarette smokers who may not quit smoking for health reasons. Public health efforts may need to consider employing e-cigarettes to promote tobacco-related harm reduction.

2014: Cigarette Users’ Interest in Using or Switching to Electronic Nicotine Delivery Systems (ENDS) for Smokeless Tobacco for Harm Reduction, Cessation, or Novelty: A Cross-Sectional Survey of US Adults

This study highlights higher interest in ENDS versus smokeless tobacco and greater interest in both for harm reduction and cessation than due to novelty or smoking restrictions. 27.2% of current smokers had talked with a health care provider about ENDS, with 18.0% reporting that their provider endorsed ENDS use for cessation. Developing educational campaigns and informing practitioners about ENDS as cessation or harm reduction aids is critical.

2013: E-Cigarettes: Prevalence and Attitudes in Great Britain

While we found evidence supporting the view that e-cigarette use may be a bridge to quitting, we found very little evidence of e-cigarette use among adults who had never smoked. British smokers would benefit from information about the effective use, risks, and benefits of e-cigarettes, as this might enable the use of e-cigarettes to improve public health.

2013: EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as Tobacco Cigarettes Substitute: A Prospective 12-Month Randomized Control Design Study

Conclusion: “In smokers not intending to quit, the use of e-cigarettes, with or without nicotine, decreased cigarette consumption and elicited enduring tobacco abstinence without causing significant side effects.”

2013: 'Vaping' profiles and preferences: an online survey of electronic cigarette users

“FINDINGS: Seventy-four percent of participants reported not smoking for at least a few weeks since using the e-cigarette and 70% reported reduced urge to smoke. Seventy-two percent of participants used a 'tank' system, most commonly, the eGo-C (23%). Mean duration of use was 10 months. Only 1% reported exclusive use of non-nicotine (0 mg) containing liquid. E-cigarettes were generally considered to be satisfying to use; elicit few side effects; be healthier than smoking; improve cough/breathing; and be associated with low levels of craving. Among ex-smokers, 'time to first vape' was significantly longer than 'time to first cigarette' (t1104  = 11.16, P < 0.001) suggesting a lower level of dependence to e-cigarettes. Ex-smokers reported significantly greater reduction in craving than current smokers (χ(2) 1  = 133.66, P < 0.0007) although few other differences emerged between these groups. Compared with males, females opted more for chocolate/sweet flavours (χ(2) 1  = 16.16, P < 0.001) and liked the e-cigarette because it resembles a cigarette (χ(2) 3  = 42.65, P < 0.001). CONCLUSIONS: E-cigarettes are used primarily for smoking cessation, but for a longer duration than nicotine replacement therapy, and users believe them to be safer than smoking.”

2012: The electronic-cigarette: Effects on desire to smoke, withdrawal symptoms and cognition

The e-cigarette can reduce desire to smoke and nicotine withdrawal symptoms 20 minutes after use.

The nicotine content in this respect may be more important for males.

The first study to demonstrate that the nicotine e-cigarette can improve working memory.

2011: Effect of an electronic nicotine delivery device (e-Cigarette) on smoking reduction and cessation: a prospective 6-month pilot study

Sustained 50% reduction in the number of cig/day at week-24 was shown in 13/40(32.5%) participants; their median of 25 cigs/day decreasing to 6 cigs/day (p < 0.001). Sustained 80% reduction was shown in 5/40(12.5%) participants; their median of 30 cigs/day decreasing to 3 cigs/day (p = 0.043). Sustained smoking abstinence at week-24 was observed in 9/40(22.5%) participants, with 6/9 still using the e-Cigarette by the end of the study. Combined sustained 50% reduction and smoking abstinence was shown in 22/40 (55%) participants, with an overall 88% fall in cigs/day. The use of e-Cigarette substantially decreased cigarette consumption without causing significant side effects in smokers not intending to quit

2011: Electronic cigarette: users profile, utilization, satisfaction and perceived efficacy

Almost all (97%) used e‐cigarettes containing nicotine.

Most (96%) said the e‐cigarette helped them to quit smoking or reduce their smoking (92%). Reasons for using the e‐cigarette included the perception that it was less toxic than tobacco (84%), to deal with craving for tobacco (79%) and withdrawal symptoms (67%), to quit smoking or avoid relapsing (77%), because it was cheaper than smoking (57%) and to deal with situations where smoking was prohibited (39%). Most ex‐smokers (79%) feared they might relapse to smoking if they stopped using the e‐cigarette. Users of nicotine‐containing e‐cigarettes reported better relief of withdrawal and a greater effect on smoking cessation than those using non‐nicotine e‐cigarettes.

2011: Electronic cigarettes (e‐cigs): views of aficionados and clinical/public health Perspectives

The health risks from smoking are large and are known with certainty. Comparatively, the health risks from e‐cig use are likely much smaller (if any) and temporarily switching to e‐cigs will likely yield a large health benefit. If the patient perceives that the e‐cig is helping them to stay off cigarettes and is not reporting any health problems likely attributable to the e‐cig, then the focus should be on staying smoke‐free rather than e‐cig free.

2011: Electronic Cigarettes As a Smoking-Cessation Tool: Results from an Online Survey

A large percentage of respondents reported a reduction in the number of cigarettes they smoked (66.8%) and almost half reported abstinence from smoking for a period of time (48.8%). Those respondents using e-cigarettes more than 20 times per day had a quit rate of 70.0%. Of respondents who were not smoking at 6 months, 34.3% were not using e-cigarettes or any nicotine-containing products at the time.

2011: Interviews With “Vapers”: Implications for Future Research With Electronic Cigarettes

Experienced users report health gains typical for smoking cessation despite continued vaping. There were pervasive themes including the language and culture of vaping; social and informational support among vapers, motives and perceived benefits of using e-cigs versus cigarettes including cigarette-like enjoyment, cost, restored sense of taste and smell, and improved breathing and exercise tolerance; rapidly reduced nicotine tolerance and dependence; and a strong interest in e-cig–related research and policy.

2010: Effect of an electronic nicotine delivery device (e cigarette) on desire to smoke and withdrawal, user preferences and nicotine delivery: randomised cross-over trial

Conclusions “The 16 mg Ruyan V8 ENDD alleviated desire to smoke after overnight abstinence, was well tolerated and had a pharmacokinetic profile more like the Nicorette inhalator than a tobacco cigarette. Evaluation of the ENDD for longer-term safety, potential for long-term use and efficacy as a cessation aid is needed.”

2010: Electronic cigarettes: a survey of users

Our results suggest that ecigarettes are used mainly to quit smoking, and may be useful for this purpose.

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