The E-Cigarette Debate: What Counts as Evidence?

Amy Lauren Fairchild, PhD, MPH; Ronald Bayer, PhD; Ju Sung Lee, MHA


Am J Public Health. 2019;109(7):1000-1006. 

In This Article

The Politics of Harm Reduction

The public health culture that informs the approach to e-cigarettes and smoking harm reduction make England stand apart. PHE is engaged in continual assessment of a policy path it started down years ago. Its mission has been to act in every way possible to reduce the threat to the health and life of smokers. Their current commitment is not to determine whether to recommend e-cigarettes. They already do. Rather, the issue was whether to retreat from an established policy position because of new evidence. This focus on identifying harms made it imperative for PHE to systematically review heated tobacco products, which were new to the market in 2018. Overall, the focus remains trained on the grave health risks to smokers themselves.

The policy context in which the FDA commissioned the NASEM analysis of the impact of e-cigarettes on health outcomes and the limits of the available evidence favored precaution:

"With only few exceptions the epidemiological literature is quite limited and even where it is strongest (assessing short-term cardiovascular and respiratory effects) it does not address the etiology of chronic diseases. In other cases such as cancer and reproductive health, there is simply no available epidemiological research to consider. [11] (p46)"

Lack of evidence of harm was insufficient for NASEM: they insisted on proof of safety, particularly when the youth uptake was in question.

On the question of efficacy, the research community has yet to reach consensus about what represents an adequate study design to support smoking harm reduction. Nonetheless, new evidence that seems to meet a high evidentiary bar is already widening the divide between England and the United States, underscoring the power of the underlying political framings. In January 2019, the New England Journal of Medicine published the results of a major randomized clinical trial on the efficacy of e-cigarettes.[29] It concluded that e-cigarettes were more effective for smoking cessation than nicotine replacement therapy among those who made the decision to attend a stop smoking service and when combined with a behavioral intervention lasting at least 4 weeks. After 1 year, 18.0% of the e-cigarette group was tobacco abstinent compared with only 9.9% of the nicotine replacement group. For e-cigarette users who were not tobacco abstinent, the problem of dual use remained. The study supports the PHE approach of combining easy access to e-cigarettes with behavioral intervention.[30]

Of the just-released randomized controlled trial, the deputy director of the Tobacco and Alcohol Research Group at London's University College told CNN, "This study should reassure policymakers and health professionals—mainly beyond the UK—who have until now been hesitant to recommend e-cigarettes for smoking cessation on the basis that there was a lack of high-quality trial evidence."[31] University of California at San Francisco researcher Neil Benowitz described the study to the New York Times as "seminal."[32] Others, however, focused not on the finding that e-cigarettes were twice as effective at helping cessation but that 80% of those in the e-cigarette group continued to vape after 1 year compared with only 9% in the nicotine-replacement group who were still using their assigned product. This raised concerns not only about the long-term health effects but also the risk to adolescents. Data from the Population Assessment of Tobacco and Health study have raised similar concerns for some,[33] while others see in them no evidence of a threat.[34] Increasingly, however, concerns are shifting away from the gateway threat and toward the threat that nicotine itself poses. The American Lung Association stated, "Switching to e-cigarettes does not mean quitting… . Quitting means truly ending the addiction to nicotine."[35]

The fear of "addicting a generation of youth" to nicotine continues to define US skepticism.[36] The most recent National Youth Risk Behavior Survey showed that vaping in the past 30 days increased from 0.6% to 4.9% among middle-school students and 1.5% to 20.8% among high-school students between 2011 and 2018. During that period, regulators were most alarmed by a spike between 2017 and 2018: past-30-day e-cigarette use increased 48% among middle schoolers and 78% among high schoolers. FDA Commissioner Gottlieb, describing the situation as an epidemic, said, "These data shock my conscience."[36] In those same school-age groups, however, combustible cigarette smoking declined 4.3% and 15.8% between 2011 and 2017.[37] However, according to most recent Centers for Disease Control and Prevention data, "no significant change in frequent use was observed for other tobacco products."[38] A recent 2019 PHE evidence update cites new Action on Smoking and Health data that show similar trends: between 2014 and 2018, the percentage of youths reporting that they had ever tried an e-cigarette increased from 6.5% to 11.7%; during that same period, the percentage of youths who were current vapers increased from 1.6% to 3.4%.[32] Youth smoking use and experimentation decreased between 2017 and 2018. As in the United States, media attention focused on sizeable increases in the rate of e-cigarette experimentation.

It is not yet possible to definitively conclude that e-cigarettes divert youths from or drive them to combustible products, but the data "paint a consistent picture of accelerated reductions in youth and young adult smoking prevalence as vaping became more widespread."[39] (p6) Iowa Attorney General Tom Miller, who with 45 of his peers in other states led the lawsuit against the tobacco industry that produced the Master Settlement Agreement, cited a study in the November 2018 issue of Tobacco Control demonstrating that the majority of adolescents aged 15 to 21 years vaped fewer than 10 days a month.[40] Miller argued that it is imperative to take the threat to kids seriously. Nonetheless, he concluded, "If there is an epidemic, it is an epidemic of casual use. There is no real fear of addicting a generation—2 percent does not make a generation."[41]

Even in the absence of worrisome trends in e-cigarette experimentation among youths, the FDA crackdown on underage sales would be ethically justified. But youths have a right to know the great difference between the risks associated with vaping nicotine and the risks associated with using combustible tobacco even if that information results in an increase in e-cigarette experimentation and use. Although uncertainty remains about how much safer e-cigarettes are when compared with combustible products, by either the NASEM or the PHE evidentiary standard, it is no longer possible to argue that e-cigarettes are as or more harmful than smoking. In its zeal to protect youths, public health leadership must refrain from misrepresenting the conclusive evidence that they are safer.

The position taken by the New England Journal of Medicine indicates just how difficult that will be: in the issue of the journal reporting the results of the clinical trial demonstrating that e-cigarettes are twice as effective at promoting cessation as combinations of nicotine replacement therapy, the editors painted an alarming epidemiological picture.[42] The editors repeated NASEM conclusions without ambiguity, "There is substantial evidence that e-cigarette use by youth increases the risk of smoking combustible tobacco cigarettes."[42](p679) In the United States, youths have been the focal point of that picture. With FDA Commissioner Gottlieb's resignation, it is uncertain what path that agency will now chart, particularly as conservative antiregulatory advocacy groups—some funded by Altria—pressure the current presidential administration to remove regulatory obstacles to e-cigarettes and possibly combustible products. Likewise, whether England can maintain a broad field of vision that includes smokers, who are immediately in harm's way, remains to be seen. Correcting worsening public health misperceptions that might prevent smokers from switching while regulating e-cigarettes and combustible products out of the hands of kids represents a kind of ethical bottom line. So, too, does monitoring the impact of e-cigarettes on smoking rates as Big Tobacco absorbs more of the vaping industry. But keeping our eyes on the full picture is also imperative: as noted previously, there is a dose–response relationship between adult smoking and youth uptake. A 2017 cohort study concluded, "Adult smoking is a preventable and modifiable risk factor for children smoking."[43] (p13)While trade-offs remain inevitable, smoking harm reduction that benefits current smokers does not simply throw youths under the bus. It is against such standards of candor that we must judge efforts to address the threats posed by smoking and vaping.