Tobacco and vaping industry skews studies to favor its commercial interests

A paper published in the journal Tobacco Control[1] by US academics shows how tobacco and nicotine industry-funded studies on vaping have methodological flaws that lead to misleading conclusions that support the industry's commercial goals. They caution that tobacco and nicotine industry-funded studies should be reviewed by experts in the field who have no connection to the industry.

An analysis of studies on e-cigarettes and their health effects found that studies whose authors had a financial conflict of interest (i.e., the research was supported by funding from the tobacco, vaping, or pharmaceutical industries) were 91.5 times more likely to report that e-cigarettes were associated with less harmful health effects than studies that did not have a financial conflict of interest.

Methodological flaws that lead to misleading conclusions that further tobacco industry goals

The authors caution that while some industry-funded studies appear methodologically sound at first glance, closer examination sometimes reveals flaws that lead to misleading conclusions, often in favor of an industry agenda and in direct contradiction to other non-industry-funded research findings. The academics cite a recent study funded by the manufacturer Juul Labs, Inc. (Altria) as an example.[2] who concluded that "Controlled use of the Juul e-cigarette containing 50 mg/mL nicotine by adult smokers of combustible cigarettes poses less risk of abuse than combustible cigarettes and may provide sufficient nicotine to support substitution from combustible cigarettes (compared to some nicotine replacement products such as chewing gum)".

However, a closer look at the study protocol reveals that participants were asked to take 10 puffs of each study product (a JUUL e-cig with 50 mg/ml nicotine, a VUSE e-cig with 48 mg/ml nicotine, and a combustible cigarette of the smoker’s usual brand), at approximately 30-second intervals. Each puff was to be 3 seconds long. Data from non-industry-funded studies, however, show that 3-second puffs are shorter than typical puffs taken by people who regularly use e-cigarettes (e.g., 5.6 seconds average puff duration) and longer than typical puffs taken by people who regularly smoke cigarettes (e.g., <2 seconds puff duration). Therefore, this protocol likely resulted in a nicotine delivery that was higher than that of cigarettes and lower than that of e-cigarettes compared to what is common in the real world. Furthermore, the published paper does not present any behavioral data demonstrating how well the 10-puff, 30-second interpuff, and 3-second puff procedure was followed by participants.

The appeal of flavored e-cigarettes to youth is another example of tobacco and nicotine industry-funded research. The scientific literature agrees that flavor is one of the most attractive features of e-cigarettes for youth and young adults. Many studies highlight these attractive flavors as a primary reason for e-cigarette initiation and use. However, a 2014 tobacco industry-funded study on the impact of e-cigarette flavor descriptors on product appeal concluded that "Interest in e-cigarette flavors was lower among youth than adults". In this study, the authors asked participants to answer the following question: “How interested would you be in using a (flavor) (product)?” with flavors including bubble gum, cotton candy, and gummy bear. The products examined included flavored water bottles, ice cream, and e-cigarettes, in a balanced sampling design, which the authors say “validates the assessment.”

A closer look at the methods reveals that the authors compared ratings between adults who currently smoke cigarettes and nonsmoking adolescents. Additionally, any adolescent who smoked or had tried an e-cigarette in the past was excluded from the study. Furthermore, the online survey design did not include any visual stimuli such as “mockups of actual products… in order to focus the evaluation on flavors and not graphics or other features.” This approach may diminish the appeal of flavors for all products studied. In the real world, flavored e-cigarettes are marketed with appealing images and descriptors that promote the product’s tastes, sensations, and experiences in great detail.

Finally, an analysis by Pinney Associates, a US-based health consultancy funded exclusively by Juul Inc. Lab since 2019, examined data from the 2010-2019 National Health Interview Survey. The study, published in the journal BMC Public Health, assessed prevalence rates of cigarette and e-cigarette use over time. The authors concluded: "Population-level data suggest that smoking prevalence has fallen more rapidly than expected, in line with increasing e-cigarette use". The authors of the Tobacco Control paper caution that population-level data should not be used to draw conclusions at the individual level. A decline in smoking rates that coincides with an increase in e-cigarette use does not necessarily indicate that people have switched from cigarettes to e-cigarettes and could have been caused by other factors.

A detailed analysis of the methodology shows that the statistical analysis included linear interpolation from an assumed zero prevalence of e-cigarette use in 2010 to the average for the years 2014–2019. The prevalence data clearly demonstrated that the linear interpolation did not fit the data based on the figures included in the tobacco industry analysis. Furthermore, most of the results became statistically insignificant when the interpolated data were omitted, but these details are in supplementary files that are not available to readers. This study has been retracted[3] by BMC magazine due to "the hypothesis of a "0" prevalence of e-cigarette use in 2010, which contradicts the available data and led the editors to lose confidence in the results presented in the article."

Increased vigilance over nicotine industry-funded studies

The authors call on researchers, health professionals, regulators and the public to view tobacco industry-funded studies, including studies funded by the vaping industry, with a skeptical eye. The authors support the position taken by the BMJ Journal Tobacco Control which: "will not accept for publication articles reporting work funded, in whole or in part, by a tobacco manufacturer or tobacco industry organization. Nor will the journal consider articles from authors who accept funding from the tobacco industry, including funding for research costs, for all or part of an author's salary, or other forms of personal compensation."

The authors argue that it is essential to explicitly include the vaping industry in this policy, and in particular to exclude articles written by people who receive funding from this industry. They point out that policy debates must be based on a transparent and robust body of research. For them, because of the methodological flaws present in research funded by the tobacco and vaping industries, any research funded by this industry must be subject to careful and detailed review by completely independent experts in the field.

©Generation Without Tobacco

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[1] Soule EK, Rossheim ME, Livingston MD, et al Hidden flaws in e-cigarette industry-funded studies Tobacco Control Published Online First: 11 June 2024. doi: 10.1136/tc-2024-058609

[2] Goldenson NI, Buchhalter AR, Augustson EM, et al. Abuse liability assessment of the JUUL system in four flavors relative to combustible cigarette, nicotine gum and a comparator electronic nicotine delivery system among adult smokers. Drug Alcohol Depend 2020;217:108395. doi:10.1016/j.drugalcdep.2020.108395

[3] Foxon, F., Selya, A., Gitchell, J. et al. Retraction Note: Population-level counterfactual trend modeling to examine the relationship between smoking prevalence and e-cigarette use among US adults. BMC Public Health 23, 1898 (2023). https://doi.org/10.1186/s12889-023-16800-7