A new review paper in Nicotine and Tobacco Research, published by Oxford University Press, finds that while research has previously found that vaping is associated with subsequently quitting smoking, that may not always be true. In fact, it appears studies limited to people who actually want to quit smoking are less likely to find this relationship.
Tobacco smoking, in particular cigarette smoking, remains prevalent and is the leading cause of preventable death in the world. Most cigarette smokers express a desire to quit, but quitting is difficult. In the U.S., Food and Drug Administration-approved smoking cessation medications with demonstrated efficacy are available (mostly nicotine replacement therapy drugs such as varenicline and bupropion), but their use remains low. Although smoking prevalence in the U.S. has been declining, among the 28.8 million US adults who smoked cigarettes in 2022, approximately 67.7% were interested in quitting, 53.3% attempted to quit in the past year, 36.3% used medication to quit smoking, but only 8.8% were successful.
Nicotine Vape Products (also known as e-cigarettes) may help smokers quit smoking. Vaping has been increasing notably since 2010, with adult prevalence of current use estimated to be approximately 6% in 2022. Most users of vaping devices are current or former cigarette smokers, and there is higher use among younger smokers compared to older smokers. This finding may suggest that smokers turn to vaping as an alternative to traditional cigarettes, potentially using them as a tool to reduce or stop smoking.
Controversy remains regarding whether vape products are effective at helping people quit smoking. This is because reviews have largely overlooked studies using the same data source. To address this gap, investigators here conducted a narrative review to examine the differences in the reported association of studies that used data from the same source, the Population Assessment of Tobacco and Health (PATH) Study, a national longitudinal long-term study of tobacco and nicotine use in the United States. The researchers here extracted and summarized key study characteristics, including inclusion criteria, participant characteristics, study duration, and definitions of vaping exposure and smoking outcomes.
There are four key findings from the 38 reviewed studies. First, 63.2% of studies reported that vape product use was associated with increased odds of cigarettes cessation within one to three years, while the remaining studies did not find evidence of a positive association. Second, the absence of a positive association does not necessarily indicate that NVPs are ineffective. In several studies, vaping was compared with FDA-approved treatments (like varenicline or bupropion); in these contexts, vaping may not have appeared beneficial because it was not significantly better than established medical aids. Third, daily vape use was a stronger predictor of successful cessation than intermittent, occasional, or no use. Finally, study findings varied by sample selection: studies that included participants regardless of quit intention were more likely to report positive association than those restricted to smokers actively reported an intention to quit. Specifically, positive association were observed in 85% of studies without such restrictions, compared with 35.3% of studies limited to individuals attempting to quit using vape products.
"Regarding the association between vape products and smoking cessation, researchers are advised against making broad claims based on any single study in general, and to be vigilant when multiple research teams analyze the same data," said the paper's lead author, Shu Xu. "Multiple studies using the same data source must be carefully examined in order to synthesize evidence and assess consistency of the findings.
The paper, "Effectiveness of Nicotine Vape Products (E-cigarettes) as a Smoking Cessation Aid for US Adults - A Narrative Review of Findings from the Population Assessment of Tobacco and Health Study," is available (at midnight on April 30th) at https://doi.org/10.1093/ntr/ntag068 .
Direct correspondence to:
Shu Xu
Department of Biostatistics, School of Global Public Health
New York University
708 Broadway, 4th Floor
New York, NY 10010
