An unbalanced consideration of the risks and benefits of e-cigarettes

Several people have asked me what I thought of the recent essay by Balfour et al and a group of former presidents of the Society for Nicotine and Tobacco Research, “Balancing consideration of the risks and benefits of e-cigarettes,” that argues that concerns over youth e-cigarette use needs to be “better balanced” against the value of e-cigarettes for adult cessation. Ken Warner “wrote much of the original draft of the article and supervised revisions.”

This is, of course, a particularly timely question as the FDA Center for Tobacco Products considers whether to authorize marketing of particular e-cigarettes as “appropriate for the protection of public health” as the court-imposed September 9, 2021 deadline approaches.

In preparing my assessment, I found “E-cigarettes and harm reduction: An artificial controversy instead of a well-framed discussion decision context” by Jon Samet and Jessica Barrington-Trimis that did a fine job of putting the paper Warner organized in context so I stopped my effort to draft a response to it. In particular Samet and Barrington-Trimis state:

The authors’ [Balfour et al] review leads them to conclude that e-cigarettes’ risk trade-off benefits population health overall. We do not agree that the evidence presented is sufficient to support their conclusion. Their evidence comes from a selective and opaque review process that does not meet standards for systematic review or for evidence integration, as in the US Surgeon General reports on smoking and health. In particular, the risks of nicotine (and e-cigarettes specifically) for youths are minimized in the face of much (uncited) longitudinal evidence of its dangers (e.g., increase in the frequency and intensity of cigarette smoking, risk of nicotine dependence). Nicotine is a known addictive chemical; disposable and pod based products that administer nicotine in very high concentrations with little adverse sensory effect are addicting youths now. E-cigarettes do harm the adolescent’s still-developing lungs, and e-cigarette– and vaping-associated lung injury outbreak points to the dangers of inhaling unregulated aerosols from carefully engineered devices intended to maximize the aerosol dose reaching the lungs. [references omitted]

Samet and Barrington-Trimis also address the key questions around e-cigarettes and smoking cessation:

The question to be answered for decisions on e-cigarettes—and the risk trade-offs—needs to be better specified; in the current marketplace for tobacco products (or in a better regulated future marketplace), does the availability of e-cigarettes in commercial outlets lower the prevalence of tobacco product use among adult cigarette smokers and reduce the frequency of tobacco-caused disease without increasing nicotine addiction among young people? This question is not addressed by the highly artificial randomized clinical trials on e-cigarettes and cigarette-smoking cessation, which focus only on the method of nicotine delivery (i.e., via e-cigarettes). There is some evidence that e-cigarettes may be associated with increases in smoking cessation among those who use e-cigarettes daily (compared with those who use alternative cessation methods). The findings of trials that provide free e-cigarettes (vs conventional cessation therapy) also indicate increased cessation with the e-cigarette intervention. However, we do not know whether the effectiveness and reach of e-cigarettes as a cessation aid depend on ready availability in retail locations (e.g., in vape shops, pharmacies, and convenience stores), which has the consequence of making them more accessible to youths. [references omitted]

They close, “The public health research and practice communities can be most helpful to setting this course by providing the needed evidence and facilitating its interpretation in a well framed decision context. An unneeded schism and polarization are antithetical to what should be happening now.“

I agree.

An example of selective quotation

While I have decided Samet and Barrington-Trimis have made my detailed commentary unnecessary, I do think it is important to illustrate how Warner and his coauthors have selectively quoted my own work. They refer to our meta-analysis of e-cigarettes and smoking cessation to support their statement, “Other researchers have found regular and frequent e-cigarette use to be associated with increased smoking cessation, while infrequent use was not.”

It is correct that we found that daily e-cigarette use was associated with significant increases in cigarette cessation (OR 1.529; 95% CI 1.158 – 2.019). But we also found that non-daily use was, however, associated with significantly less quitting (OR 0.514; 95% CI 0.402 – 0.656). Most important, among all users, there was no significant association with quitting, the key conclusion in our paper.

Warner and colleagues ignored this point and instead focused on criticizing our earlier meta-analysis that was superseded by the new paper (which was based on much more information so not suffer from the limitations of the earlier work).

In particular, compare how Warner and colleagues represent our work with what abstract for our new meta-analysis says:

Objectives. To determine the association between e-cigarette use and smoking cessation. Methods. We searched PubMed, Web of Science Core Collection, and EMBASE and computed the association of e-cigarette use with quitting cigarettes using random effects meta-analyses. Results. We identified 64 papers (55 observational studies and 9 randomized clinical trials [RCTs]). In observational studies of all adult smokers (odds ratio [OR] = 0.947; 95% confidence interval [CI] = 0.772, 1.160) and smokers motivated to quit smoking (OR = 0.851; 95% CI = 0.684, 1.057), e-cigarette consumer product use was not associated with quitting. Daily e-cigarette use was associated with more quitting (OR = 1.529; 95% CI = 1.158, 2.019) and less-than-daily use was associated with less quitting (OR = 0.514; 95% CI = 0.402, 0.665). The RCTs that compared quitting among smokers who were provided e-cigarettes to smokers with conventional therapy found e-cigarette use was associated with more quitting (relative risk = 1.555; 95% CI = 1.173, 2.061). Conclusions. As consumer products, in observational studies, e-cigarettes were not associated with increased smoking cessation in the adult population. In RCTs, provision of free e-cigarettes as a therapeutic intervention was associated with increased smoking cessation. Public Health Implications. E-cigarettes should not be approved as consumer products but may warrant consideration as a prescription therapy.