e-Cigarettes Don't Help Smokers Quit, Study Finds

Heidi Splete

February 10, 2022

Use of e-cigarettes was not more effective than other methods at helping cigarette smokers quit, authors of new research found.

From 2013 to 2017, e-cigarette sales in the United States nearly doubled, driven by a rapid uptake of use by adolescents, wrote Riufeng Chen, MD, of the University of California, San Diego, and colleagues, in their paper published in Tobacco Control. However, the subsequent effect of increased e-cigarette use on smoking cessation have not been examined, they said.

In their study, Chen and colleagues analyzed data from 3,578 previous-year smokers with a recent quit attempt and 1,323 recent former smokers who were part of the PATH cohort in 2017. The participants reported using e-cigarettes or other products to quit cigarette smoking. The primary outcomes were at least 12 months of cigarette abstinence, and tobacco abstinence in 2019. In 2017, 32.8% of established smokers reported trying to quit. Of these, 12.6% used e-cigarettes to help them quit. Cigarette abstinence for at least 12 months for these individuals was 9.9%, which was lower than for those who used either nicotine replacement therapy or a pharmaceutical aid only (15.2%), and about half of the 18.6% abstinence in those who used no products to help them quit.

"In our study, e-cigarettes resulted in seven fewer successful quitters than those who used pharmaceutical aids," emphasized corresponding author, John P. Pierce, PhD, of the University of California, San Diego.

Among smokers attempting to quit, the adjusted risk difference for cigarette abstinence for a least 12 months with e-cigarettes vs. pharmaceutical aids was –7.3%, and –7.7% for e-cigarettes vs. other smoking cessation methods.

"Among recent former smokers who had switched to daily use of e-cigarettes in 2017, 43.2% had successfully quit cigarette smoking by 2019, which was similar to those who used e-cigarettes on a nondaily basis (34.6%) or to those who switched to another tobacco product, whether daily (43.6%) or nondaily (44.7%)," the researchers wrote.

The rapid growth in e-cigarette use between 2014 and 2017 has been attributed in part to aggressive marketing of high-nicotine e-cigarettes, they said. "The high-nicotine JUUL e-cigarette has been noted as the closest match to cigarettes in both nicotine delivery and user satisfaction, which should make it one of the best candidates as a product to which smokers could switch in order to maintain their nicotine habit," they said in their discussion of the findings.

More Research Needed

The researchers acknowledged the need to review more recent data.

"When we looked ahead to 2019, recent former smokers had started using high-nicotine e-cigarettes. The effectiveness of high-nicotine e-cigarettes at preventing relapse will require another follow-up PATH survey," they said.

Among recent former smokers, 2.2% reported switching to a high-nicotine e-cigarette. Although individuals who switched to e-cigarettes showed a higher rate of relapse to cigarettes than those who did not switch to other tobacco or e-cigarette products, this difference was not significant.

The study findings were limited by several factors including the observational design and inability to control for all potential confounding factors, the researchers noted. However, the results were strengthened by the use of a large and representative study population, and the inclusion of biological samples to validate self-reported smoking, they said.

Several Findings Surprised Study Author

Pierce said he was surprised by several aspects of the study findings.

"First of all, contrary to what we expected, there was a 25% decline in using e-cigarettes to quit, compared to the previous year (not the 40% increase that was expected from the increase in e-cigarette sales) and almost no smokers were using high-nicotine JUUL products to help them quit," he said. "In this study, e-cigarettes were much less helpful (7 less successful quitters per 100) than pharmaceutical cessation aids in helping people quit," he added.

"The fact that the proportion of smokers using e-cigarettes for cessation dropped from 17% to 12% was unexpected, and it suggests that the belief that they are a cessation aid is declining," he said.

The implication for clinical practice is that e-cigarettes are not a useful tool for smoking cessation, Pierce said. "We are not finding any evidence in this very large nationally representative study that smokers who switch to getting their nicotine from e-cigarettes are less likely to relapse back to cigarette smoking," he said.

"We don't know about the high-nicotine versions," he added.

New Review Advises Against e-Cigarettes for Cessation

A recent review article published in JAMA supported the use of pharmacotherapy and behavioral support for smokers wanting to quit. In the review, Nancy A. Rigotti, MD, of Massachusetts General Hospital, Boston, and colleagues summarized the evidence for managing tobacco smoking in clinical practice.

"The health risk from cigarette smoking is primarily due to chemicals produced by the burning of tobacco and not to nicotine," they noted. However, the physical dependence on nicotine makes quitting a challenge, but it is one worth pursuing, the authors said.

The authors of this review identified 30 reviews, 12 randomized clinical trials, and 7 recent guidelines and evidence reviews. Their key message: Pharmacotherapy and behavioral support are effective when used alone, but even more effective when combined. Pharmacotherapy helps reduce the symptoms of nicotine withdrawal, while behavioral intervention tackles the challenge of changing learned behaviors associated with smoking, the researchers said.

Although combining medications, such as varenicline and nicotine replacement therapy or bupropion might improve successful quit rates, these combinations have not been well studied, they noted.

With regard to e-cigarettes, the researchers cited a 2021 Cochrane review of 16,759 individuals who used e-cigarettes for smoking cessation, which found no evidence of harm, but insufficient evidence to asses the balance of risks vs. benefits.

In addition to the lack of randomized trials, "the FDA regulates e-cigarettes as tobacco products, not as medical products and has not evaluated any e-cigarette for medical use as a cessation aid," the authors of the new review noted.

The review was limited by several factors, including the lack of quality assessment for the selected studies and the exclusion of pharmacotherapy not licensed in the United States.

Commenting on the JAMA paper, Pierce said, "This review looks like a number of Cochrane Reports that have been published recently. Of course, it only considers randomized trials and not population evidence."

"If public health had limited itself to this form of evidence, then we still would not know that smoking caused cancer," he noted. "Randomized trials are very important for testing new drugs; they use selected populations and provide considerable support that is not available in the real world. Sometimes they do not generalize to the population."

Findings May Guide Patient Conversations

The Tobacco Control study was important, because few studies on e-cigarettes have been conducted, said Linda Girgis, MD, a family physician in private practice in South River, N.J., in an interview.

"As clinicians, we do not have a lot of data available in order to make clinical decisions that are evidence based. Also, getting patients to quit smoking is often very difficult, and having more tools available is a great benefit; however, we need to have the evidence that these tools are effective," she said.

Girgis also said she was not surprised by the findings.

"Patients still have the same concerns from e-cigarettes regarding nicotine exposure, but just to a lesser degree; and we still don't know the long-term effects of e-cigarette use, she said. Based on these studies, recommending e-cigarettes for smokers looking to quit may not be the best method, she noted.

"While it may seem reasonable that exposing lungs to lower doses of nicotine will reduce harm, we need to see actual evidence of this. Also, we also need to study the additives that are frequently used in e-cigs, such as artificial flavorings, to see what harms they may pose, she emphasized.

With regard to the JAMA review, Girgis said she agreed with the recommendations for pharmacotherapy and behavior therapy as first-line treatments for smoking cessation. "There is evidence regarding the efficacy and safety of these methods, and they have been used for decades," she said.

Girgis added that there is a role for e-cigarettes in smoking cessation strategies as a method of harm reduction, but pointed out the problem of many people thinking these products are safe and not understanding the hazards they pose.

"They think they can replace smoking with e-cigarettes and be safe from the health risks associated with smoking. I think if the plan were to switch to e-cigarettes for a short period and then quit, there would be a role," Girgis said. "However, replacing one risk for another may reduce harm, but doesn't eliminate it."

"To continue to use e-cigarettes indefinitely should not be the goal," she added.

The Tobacco Control study was funded by the National Institutes of Health and the Tobacco-Related Disease Research Program of the University of California. The researchers had no financial conflicts to disclose.

The JAMA study was funded in part by a grant from the National Institute for Health Research, via Cochrane Infrastructure funds to the Cochrane Tobacco Addiction Group. Lead author Rigotti disclosed funding from the National Heart, Lung, and Blood Institute and Achieve Life Sciences and personal fees from UpToDate and Achieve Life Sciences. Girgis had no financial conflicts to disclose.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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