Researchers at the Herbert Wertheim School of Public Health and Human Longevity Science and Moores Cancer Center at University of California San Diego have found that, among smokers in the United States, e-cigarette use does not increase smoking cessation and is actually associated with reduced tobacco abstinence.
The findings, published March 5 in JAMA, refute the notion that e-cigarettes can help people quit, a common misperception among tobacco users and e-cigarette proponents.
“Most smokers think vaping will help you quit smoking,” said study co-author John P. Pierce, Ph.D., Distinguished Professor in the Herbert Wertheim School of Public Health. “However, this belief is not supported by science to date. While some researchers have suggested that smokers who switch to daily vaping will be more successful in quitting smoking, We studied quitting success among both daily and non-daily vapers and came up with a quite definitive answer.”
The new study analyzed data from over 6,000 U.S. smokers from the Population Assessment of Tobacco and Health Study, a nationally representative sample of U.S. cigarette smokers. There were 943 smokers who also vaped and by matching and comparing these to similar smokers who didn’t vape, they found:
- Smoking cessation was actually 4.1 percent lower among smokers who vaped daily.
- Similarly, smoking cessation was 5.3 percent lower among smokers who vaped, but not daily, compared to matched smokers who did not vape.
According to the CDC, almost 20 percent of people in the U.S. use tobacco products. While the majority of these people are cigarette smokers, some people have switched from smoking to vaping in recent years, in part because vaping is generally perceived as less harmful. This perception contributes to the belief among many smokers that vaping is an effective way to “taper off” of cigarettes.
Considering the potential dangers of vaping, the researchers note that while e-cigarettes don’t have the same health consequences as smoking, they are not harmless.
“The adverse health effects of cigarette smoking become obvious after people have smoked for 20 years,” added Pierce, a former director for population sciences at Moores Cancer Center. “While vapes generally don’t contain the same harmful chemicals as cigarette smoke, they have other risks, and we just don’t yet know what the health consequences of vaping over 20 to 30 years will be.”
One unique strength of the study is that the researchers were able to control for a wide range of other variables that are well-known to be associated with quitting, including whether they were non-daily cigarette smokers, interest in quitting (including a recent quit attempt), the presence of a smoke-free home, and socioeconomic factors.
“For example, if a smoker is already very interested in quitting, has a smoke-free home, and does not smoke daily, they are much more likely to successfully quit regardless of whether they vape or not,” said senior author Karen Messer, Ph.D., professor of biostatistics in the Herbert Wertheim School of Public Health. “We matched each smoker/vaper on such characteristics. You have to make very sure you’re comparing like with like, and that’s why this analysis is so definitive.”
According to the researchers, failing to adequately account for these confounding factors in previous studies is part of why misconceptions about e-cigarettes have persisted so long.
"As the public health community continues to grapple with the complexities of tobacco control, it is essential that we rely on rigorous scientific evidence to inform our policies and interventions,” added Messer, who is also director of the Biostatistics Shared Resource at Moores Cancer Center. “Our research shows that misleading associations between vaping and smoking cessation routinely occur unless confounding characteristics are carefully accounted for.”
In addition to providing definitive evidence about a contentious question in tobacco research, the study's results have important implications for public health policy and practice surrounding e-cigarettes, particularly how they are marketed to adolescents, for whom e-cigarettes are often a gateway to nicotine dependence.
“There’s still a lot we don’t know about the impact of vaping on people,” said Natalie Quach, a third-year biostatistics Ph.D. student at the Herbert Wertheim School of Public Health and the study’s first author. “But what we do know is that the idea that vaping helps people quit isn’t actually true. It is more likely that it keeps them addicted to nicotine.”
Co-authors of the study include: Jiayu Chen, Brian Dang, Matthew D. Stone, David R. Strong, Dennis R. Trinidad and Sara B. McMenamin, all at UC San Diego.
This project was supported by the Tobacco-Related Disease Research Program (TRDRP) of the University of California Office of the President (T31IR-1584 & T32IR-4988).
Disclosures: The authors report no conflicts of interest.
