Dr. John Pierce and 35 colleagues have published a study in the journal PLoS One analyzing data from FDA Population Assessment of Tobacco and Health (PATH) surveys. Their work was touted in a University of California San Diego press release titled, “E-cigarettes Don’t Help Smokers Quit and They May Become Addicted to Vaping.” But their study actually proved that e-cigarettes are as helpful as medicines promoted by anti-tobacco crusaders.
The study followed participants in all three waves of the PATH – one year apart in 2014, 2015 and 2016. I will describe how Pierce and colleagues conducted this complicated analysis.
Pierce et al. selected participants who were smoking every day when they enrolled in PATH Wave 1 (n= 9,021). They then selected those who had tried to quit smoking “in the past 12 months” between Waves 1 and 2, but who were still smoking daily (n= 2,443). In other words, those daily smokers had tried, but did not quit, during the year between the first two waves. Daily smokers who had not tried quitting were excluded.
Pierce divided those 2,443 daily smokers who had failed to quit between Waves 1 and 2 into three groups: those who had tried stop-smoking medicines (a prescription and/or over-the-counter medicinal nicotine, n=442); those who had tried e-cigarettes (n=566, 116 of whom had also used stop-smoking medicines); and those who had used neither (i.e., had gone cold turkey, n=1,435).
After the three groups of smokers had failed between Waves 1 and 2, Pierce compared them at Wave 3 (one year after Wave 2) with respect to three outcomes: abstinent from cigarettes for 12+ months; abstinent from cigarettes for 30+ days; and abstinent from all tobacco.
The researchers found that the first two outcomes for all groups were similar: “Twelve-month cigarette abstinence was ~10% and comparable across all methods used to quit… There was no net risk difference in 30+ days cigarette abstinence at W[ave]3 between the e-cigarette group and either the no e-cigarette control, the no [cold turkey group] or the [medicine group].”
While the authors apparently approved their press release headline – “E-cigarettes Don’t Help Smokers Quit” – they failed to note that e-cigarettes had helped people quit as often as medicinal nicotine, other medicines or going cold turkey. In fact, all of the quit aids helped some smokers. The headline should have read: “E-cigarettes, Nicotine Medicines, Prescription Medicines and Cold Turkey All Help Some Smokers Quit.”
Another red flag with this study is that it focused only on 2,443 “daily smokers” at Wave 1 who had tried to quit between Waves 1 and 2, but were also daily smokers at Wave 2 and additionally had information at Wave 3. That number represents a remarkably narrow subset of all daily smokers at Wave 1 (about 27% of the 9,021 daily smokers at Wave 1).
Even more important, the authors completely ignored former smokers at both Waves 1 and 2 who had already used e-cigarettes (and other aids) to quit in the year before. The Wave 1 former smokers were documented by my research group in a 2017 research study. It is entirely inappropriate for Pierce et al. to issue a press release claiming that “E-cigarettes don’t help smokers quit” when they produced results only for a select population of daily smokers who remained daily smokers after trying to quit.
While Pierce et al. narrowly defined their study groups, another study of PATH Waves 1 to 3 has produced diametrically opposite results. Investigators at New York University, Ohio State, Georgetown and Columbia, led by Allison Glasser, coauthored a study that concluded: “…consistent and frequent e-cigarette use and increasing use over time, as well as flavors and device type, are associated with smoking cessation among adult smokers.” They also found that “flavors may play a facilitating role in cigarette smoking cessation among adults. Use of a rechargeable device consistently…was also associated with a higher likelihood of smoking cessation within the past year when compared with use of disposable devices, although this effect was only found among daily smokers.”
The Pierce study and its PR spin underscore the importance of critical analysis and fact-checking of all research reports, even when “co-written” by dozens of authors and ostensibly peer reviewed.
