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Despite Claims, Real-World Evidence Shows E-Cigarettes Not an Effective Smoking-Cessation Aid

Health Letter, August 2022

By Azza AbuDagga, Ph.D.

Image: newsinhealth.nih.gov

The use of tobacco products — which contain the highly addictive substance nicotine — remains the leading preventable cause of death in the U.S. Although use of combustible tobacco products (cigarettes, cigars and other smoking products) has decreased in recent decades, the tobacco industry invented a new, sleek alternative to keep people hooked: electronic cigarettes (e-cigarettes), also called electronic nicotine delivery systems and vapes, among other things.

To promote e-cigarettes to the masses, the tobacco industry claims that these products are smoking-cessation aids, although the Food and Drug Administration (FDA) to date has not approved them for such use.

Although a number of clinical trials tend to show a positive relationship between e-cigarette use and smoking cessation, this evidence has been graded as “consistently low.” Furthermore, these trials usually are conducted under optimal therapeutic conditions, which means that their findings often do not hold in real-world, community settings, where e-cigarettes are used as consumer products.

In contrast, recent evidence from a large, U.S. nationally representative, prospective, real-world (observational) study did not show a smoking-cessation benefit for e-cigarettes when they were used either to help a cessation attempt or as an alternative to cigarette smoking. The study was published in the Feb. 7, 2022, issue of Tobacco Control.

Key facts about e-cigarettes and their regulation in the U.S.

E-cigarettes usually are battery-powered devices that come in different shapes (such as pens or flash drives [electronic memory sticks]) and contain a liquid consisting mainly of nicotine derived from tobacco, glycerin, and propylene glycol as well as flavorings. When puffed, these devices heat the liquid to create an aerosol that users inhale into their lungs.

The FDA acknowledges that e-cigarettes are not safe tobacco products. In addition to exposing users to tobacco-related disease and death, these addictive products are associated with lung injuries, seizures and other neurological adverse effects.

E-cigarette use has become increasingly prevalent. As of 2018, 8 million American adults (3% of the overall adult population) were current e-cigarette users. In addition, 5% and 21% and of American middle- and high-school students were current e-cigarette users, respectively, in that year. For this reason, VADM Jerome Adams, the former U.S. Surgeon General, declared e-cigarette use among American children an “epidemic.

After being unregulated but sold legally in the U.S. for more than a decade, many e-cigarette products have been authorized for use in adults by the FDA since October 2021. Succumbing to industry pressure, the agency argued that such authorization would be “appropriate for the protection of public health.” According to the FDA, “the potential benefit to [adult cigarette] smokers who switch completely or significantly reduce their cigarette use, would outweigh the risk to the youth [who will initiate using these products]” as long as e-cigarette companies follow the agency’s post-marketing requirements for reducing youth exposure and access to these products.

This flawed trade-off strategy has effectively thrown the youth under the bus; e-cigarettes were the most commonly used tobacco product among middle- and high-school students in 2021, according to the most recent results of the National Youth Tobacco Survey. This is because many youth users of e-cigarettes are able to obtain these products through illegal means.

On June 23, 2022, the FDA ordered the removal of all e-cigarette products made by JUUL Labs, a major seller of these products, from the U.S. market because the company did not provide sufficient evidence regarding the toxicological profile of these products, according to the agency. However, on July 5, 2022, the FDA stayed its order after JUUL filed a lawsuit against the agency and the agency determined additional review of the company’s application was warranted.

Importantly, the FDA continues to authorize the use of numerous e-cigarette products made by giants in the tobacco industry, including Philip Morris and R.J. Reynolds Vapor.

The new real-world study

The study analyzed survey data collected in 2017 (when sales for e-cigarettes increased sharply in the U.S.) and 2019 (follow-up year), respectively, as part of the Population Assessment of Tobacco and Health (PATH) cohort, a nationally representative longitudinal cohort of community-dwelling U.S. adults. The cohort has been studied for several years with funding from the National Institutes of Health and the FDA.

As part of the original study, biological samples were taken from the respondents to validate their self-reported cigarette-smoking responses. The response rate for the 2017 and 2019 surveys were 68% and 88%, respectively.

The initial PATH sample included 30,970 adults for the 2017 survey. Of this sample, there were 3,578 cigarette-smoker respondents in the 2017 survey who had attempted to quit in 2016 (recent quit attempters). Of those, 1,323 respondents had managed to quit cigarettes at the time of the 2017 survey (recent former smokers).

Recent quit attempters and recent former smokers reported whether they used e-cigarettes, smoking-cessation medications — nicotine replacement therapy (which is available in gum, inhaler, lozenge, nasal spray, patch and pill forms), bupropion (WELLBUTRIN SR and the recently discontinued ZYBAN brand) and varenicline (CHANTIX) — or did not use any product during their last quit attempt in 2016.

The researchers found that despite the large increase in e-cigarette sales in 2017, only 13% of recent quit attempters used e-cigarettes to help them quit the habit, a decline from the previous year (17%).

Remarkably, only 10% of those who attempted to quit cigarettes using e-cigarettes were abstinent from cigarettes (but not all tobacco products) for at least 12 months by 2019, which was a lower proportion than that for those who used a smoking-cessation medication only (15%) or did not use any product to attempt quitting smoking (19%).

Furthermore, only 4% of those who attempted to quit smoking using e-cigarettes were abstinent from all tobacco products (including e-cigarettes) for at least 12 months by 2019, which is a considerably lower proportion than that for those who used a smoking-cessation medication only (13%) or did not use any product to attempt quitting smoking (14%).

After the researchers adjusted their analyses for potential differences in the characteristics of respondents, they estimated that e-cigarette use was associated with seven fewer successful quitters per 100 smoking quit attempters than pharmaceutical aids. This finding contradicts findings from a previous review of evidence from clinical trials that estimated that e-cigarettes added four successful cigarette quitters per 100 quit attempters compared with pharmaceutical aids.

Overall, the current PATH analysis also showed that switching to e-cigarettes did not reduce the risk of relapse to cigarette smoking, compared with the risk for those who did not switch to these products. Instead, nearly 60% of recent former smokers who were daily e-cigarette users had relapsed to cigarette smoking by 2019.

Of note, there was a surge in the sales of high-nicotine e-cigarettes, which closely resemble in their action the experience of cigarette smoking, during the study period. However, only 2% of recent former smokers were using these products. Therefore, the researchers concluded that the e-cigarette industry was not as effective in encouraging smokers to use e-cigarettes to attempt smoking cessation as it was in encouraging youth to start nicotine use with these products.


The findings of the new study, along with those from a previous analysis of the PATH cohort, call into question the decision of the FDA to authorize the use of e-cigarettes as a consumer product.

It is not too late for the agency to truly protect the public health by banning all e-cigarette products and rejecting the false claims of the e-cigarette industry of intending to do the world any good.

Beyond e-cigarettes, the FDA should seek to increase and exercise its full statutory power to “unnicotine” America, which necessarily includes working more aggressively to help smokers quit and phasing out combustible nicotine products from the U.S. market.