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• Response to critiques on Asfar et al. in Tobacco Control: “Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies.”
  Taghrid Asfar, Rime Jebai, Wei Li, Olusanya Joshua Oluwole, Tarana Ferdous, Michael Schmidt, Seth M. Noar, Eric Lindblom, Thomas Eissenberg, Zoran Bursac, Donna Vallone and Wasim Maziak
  Published on: 7 December 2022
• Comments on paper by Asfar et al. “Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies”
  K Michael Cummings, Tracy T Smith, Steve A Schroeder, Kenneth E Warner, Ann McNeill, Jamie Hartmann-Boyce and David T Levy
  Published on: 21 October 2022

• Published on: 7 December 2022

  Response to critiques on Asfar et al. in Tobacco Control: “Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies.”

  • Taghrid Asfar, Associate Professor Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, Florida, USA.
  • Other Contributors:
    • Rime Jebai, Ph.D. Candidate
    • Wei Li, Post-Doctoral Associate
    • Olusanya Joshua Oluwole, Research Analyst
    • Tarana Ferdous, Ph.D. Candidate
    • Michael Schmidt, Associate Professor
    • Seth M. Noar, Director, Communicating for Health Impact (CHI) Lab.
    • Eric Lindblom, Lawyer
    • Thomas Eissenberg, Professor
    • Zoran Bursac, Professor
    • Donna Vallone, Chief Research Officer at Truth Initiative
    • Wasim Maziak, Professor

  We thank Cummings and colleagues for their interest in and comments on our umbrella review published recently in Tobacco Control.[1] The authors criticize us for not including the latest studies. Yet, for an umbrella review, those studies need to be in a published review to be included, as we indicated in our methods and limitations. Generally, given the lengthy review and publication processes, any review will not be inclusive of all studies in a field that has as high a publication breadth and intensity as tobacco regulatory science. In addition, the authors mentioned that our meta-analysis was not available in PROSPERO pre-registration. This is because the review registration was completed in the very early stages of the review. We have updated this information in PROSPERO now to include the meta-analysis. The issue of overlap was addressed in our limitations, as we had to screen over 3,000 studies included in our selected reviews. However, given the importance of this issue for the meta-analysis, we performed a new meta-analysis that included the individual studies in each domain instead of using the odds ratio reported by the review to eliminate the effect of including the same study more than one time on our results. We confirm that the results of the new meta-analysis, which includes each study only once, are similar to the original meta-analysis (Supplement A: https://www.publichealth.me...

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  We thank Cummings and colleagues for their interest in and comments on our umbrella review published recently in Tobacco Control.[1] The authors criticize us for not including the latest studies. Yet, for an umbrella review, those studies need to be in a published review to be included, as we indicated in our methods and limitations. Generally, given the lengthy review and publication processes, any review will not be inclusive of all studies in a field that has as high a publication breadth and intensity as tobacco regulatory science. In addition, the authors mentioned that our meta-analysis was not available in PROSPERO pre-registration. This is because the review registration was completed in the very early stages of the review. We have updated this information in PROSPERO now to include the meta-analysis. The issue of overlap was addressed in our limitations, as we had to screen over 3,000 studies included in our selected reviews. However, given the importance of this issue for the meta-analysis, we performed a new meta-analysis that included the individual studies in each domain instead of using the odds ratio reported by the review to eliminate the effect of including the same study more than one time on our results. We confirm that the results of the new meta-analysis, which includes each study only once, are similar to the original meta-analysis (Supplement A: https://www.publichealth.med.miami.edu/_assets/pdf/meta-analysis.pdf).
  The authors also accuse us of not being transparent about our adopted classification of evidence strategy, while a careful check of the reference we provided shows it (Morton et al. Page 131 (Box 4-2).[2] This classification is also adopted by the National Academies of Sciences.[3] Our assessment of the gateway effect as high evidence is consistent with this classification (National Academies of Sciences, Engineering, and Medicine 2018; Page 5, Box S-2: High evidence (including conclusive and substantial) (Supplement B: https://www.publichealth.med.miami.edu/_assets/pdf/level-of-evidence.pdf).[3] Generally, we object to the authors’ characterization that observational studies cannot imply causality. In fact, carefully designed observational studies led to most of what we know about major risks to health, such as smoking, hypertension, diabetes, and high cholesterol levels.[4-7]
  We excluded research supported by the tobacco industry, given the ample evidence of the industry's fraudulent scientific behavior, which prompts objective scientists to question the extent to which industry-sponsored authors report methods and results accurately.[8, 9] We note that our stance regarding industry-supported publications is also consistent with the policy of Tobacco Control. Contrary to the commentary’s critique, the message about nicotine’s effect on the developing brain is supported by evidence from human and animal studies and endorsed by the CDC as well as major credible public health bodies.[10-13]
  The authors state that comparing ENDS to cigarette smoking is needed, given their potential to help addicted smokers quit. Alas, an accurate comparison of these products is currently not feasible. Unlike cigarettes, which were suspected of causing lung cancer as far back as the late 19th century and for which we have more than a half-century of robust evidence of the health effects, we have much more modest literature on ENDS health effects, spanning less than two decades.[14] Also, unlike today’s combustible cigarette, a rather standardized tobacco use method with a standardized pattern of use and standardized assessment tools, ENDS are not standardized. The heterogeneity of ENDS products, their use patterns, and still nascent long-term ENDS exposure assessment tools make accurate comparisons impossible. In fact, even the same product, manufactured by the same maker, can have variability in its liquid content and ingredient proportions.[15] While the commentary criticized our review based on the acknowledged lack of long-term data about ENDS effects on health, they make an unsubstantiated claim that the group most likely to use ENDS on a persistent basis are smokers.
  To navigate the complexity of ENDS, we adopted a consumer rights stand that recognizes that every consumer needs to be aware of the potential risks and benefits of the products they are using. So, although the evidence is inconclusive about the real-world effects of ENDS in helping smokers quit, and the fact that the FDA has not yet approved any of them as a cessation device, we have created some messages to support this based on evidence from randomized clinical trials.[16] We agree that it will take more time before robust scientific evidence about the long-term effects of ENDS accumulates, but this lack of knowledge should not be an excuse for failing to alert users of potential adverse health consequences of ENDS use. The public has a right to know whether any novel product that was being used by a significant proportion of the population contains known toxicants, despite lacking robust evidence of long-term effects on health. Why should ENDS be any different?
   
  References

  1. Asfar, T., et al., Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies. Tobacco Control, 2022: p. tobaccocontrol-2022-057495.
  2. Morton, S., et al., Finding what works in health care: standards for systematic reviews. 2011.
  3. National Academies of Sciences, E., Medicine., Public health consequences of e-cigarettes. 2018.
  4. Mahmood, S.S., et al., The Framingham Heart Study and the epidemiology of cardiovascular disease: a historical perspective. The lancet, 2014. 383(9921): p. 999-1008.
  5. Doll, R., et al., Mortality in relation to smoking: 50 years' observations on male British doctors. Bmj, 2004. 328(7455): p. 1519.
  6. Kannel, W.B. and D.L. McGee, Diabetes and cardiovascular disease: the Framingham study. Jama, 1979. 241(19): p. 2035-2038.
  7. Castelli, W.P., et al., Incidence of coronary heart disease and lipoprotein cholesterol levels: the Framingham Study. Jama, 1986. 256(20): p. 2835-2838.
  8. Kessler, G., Amended Final Opinion. USA v. Philip Morris, 2006.
  9. Pisinger, C., N. Godtfredsen, and A.M. Bender, A conflict of interest is strongly associated with tobacco industry-favourable results, indicating no harm of e-cigarettes. Prev Med, 2019. 119: p. 124-131.
  10. Centers for Disease Control and Prevention. It’s not like you can buy a new brain. 2019 [cited 2022 November 29th]; Available from: https://www.cdc.gov/tobacco/basic_information/e-cigarettes/Quick-Facts-o...
  11. Goriounova, N.A. and H.D. Mansvelder, Short-and long-term consequences of nicotine exposure during adolescence for prefrontal cortex neuronal network function. Cold Spring Harbor perspectives in medicine, 2012. 2(12): p. a012120.
  12. England, L.J., et al., Nicotine and the developing human: a neglected element in the electronic cigarette debate. American journal of preventive medicine, 2015. 49(2): p. 286-293.
  13. Surgeon General, U., E-Cigarette Use Among Youth and Young Adults. A Report of the Surgeon General. 2016, Retrieved from Atlanta, GA: https://ecigarettes. surgeongeneral. gov ….
  14. Proctor, R.N., The history of the discovery of the cigarette–lung cancer link: evidentiary traditions, corporate denial, global toll. Tobacco control, 2012. 21(2): p. 87-91.
  15. Yassine, A., et al., Did JUUL alter the content of menthol pods in response to US FDA flavour enforcement policy? Tobacco control, 2022. 31(Suppl 3): p. s234-s237.
  16. Hajek, P., et al., A Randomized Trial of E-Cigarettes versus Nicotine-Replacement Therapy. N Engl J Med, 2019. 380(7): p. 629-637.

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  Conflict of Interest:
  None declared.

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• Published on: 21 October 2022

  Comments on paper by Asfar et al. “Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies”

  • K Michael Cummings, Professor, Department of Psychiatry & Behavioral Sciences Medical University of South Carolina
  • Other Contributors:
    • Tracy T Smith, Assistant Professor, Department of Psychiatry & Behavioral Sciences
    • Steve A Schroeder, Professor Emeritus, Department of Medicine
    • Kenneth E Warner, Professor Emeritus and Dean Emeritus, School of Public Health
    • Ann McNeill, Professor, Department of Addictions
    • Jamie Hartmann-Boyce, Associate Professor, Nuffield Department of Primary Care Health Sciences
    • David T Levy, Professor, Lombardi Comprehensive Cancer Center

  The paper by Asfar et al (1) had a noble objective, which was to inform ENDS health risk communications by updating the 2018 evidence review by the US. National Academies of Sciences, Engineering and Medicine (NASEM) (2). The need for improved risk communications about ENDS is reinforced by a recent study which found that only 17.4% of US smokers believe that nicotine vaping is safer than smoking (3). While ENDS use is not safe, the evidence from toxicant exposure studies does show that ENDS use is far safer than smoking cigarettes and may benefit public health by assisting those who smoke to quit smoking (4, 5).
  An important limitation of the umbrella review method utilized by the authors is that it does not directly attempt to systematically characterize new research. This is a concern because the marketplace of ENDS products used by consumers has evolved since the 2018 NASEM report (4, 5). Furthermore, the authors have included some meta-analyses of selected reviews for some domains, but these meta-analyses were not in the Prospero pre-registration (6), nor explained in the paper. It’s thus unclear how or why certain reviews were selected for meta-analysis, and also whether the comparators are the same for these reviews. More importantly, these meta-analyses risk single studies contributing multiple times to the same pooled estimate. The authors noted this as a limitation commenting inaccurately that ‘it was impossible to identify articles that were included in...

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  The paper by Asfar et al (1) had a noble objective, which was to inform ENDS health risk communications by updating the 2018 evidence review by the US. National Academies of Sciences, Engineering and Medicine (NASEM) (2). The need for improved risk communications about ENDS is reinforced by a recent study which found that only 17.4% of US smokers believe that nicotine vaping is safer than smoking (3). While ENDS use is not safe, the evidence from toxicant exposure studies does show that ENDS use is far safer than smoking cigarettes and may benefit public health by assisting those who smoke to quit smoking (4, 5).
  An important limitation of the umbrella review method utilized by the authors is that it does not directly attempt to systematically characterize new research. This is a concern because the marketplace of ENDS products used by consumers has evolved since the 2018 NASEM report (4, 5). Furthermore, the authors have included some meta-analyses of selected reviews for some domains, but these meta-analyses were not in the Prospero pre-registration (6), nor explained in the paper. It’s thus unclear how or why certain reviews were selected for meta-analysis, and also whether the comparators are the same for these reviews. More importantly, these meta-analyses risk single studies contributing multiple times to the same pooled estimate. The authors noted this as a limitation commenting inaccurately that ‘it was impossible to identify articles that were included in multiple reviews’. In our view this serious methodological flaw merits removal of all pooled estimates from their analyses. Additionally in several places, association is conflated with causality (e.g. “ENDS use impedes smoking cessation”) when based on observational data. The classification of evidence is also not transparent, cannot be found in the source the authors cited, and in places does not follow from the evidence presented (e.g. gateway evidence classified as high when based on observational studies).
  The review also excludes research reviews supported by ENDS manufacturers. While we recognize and agree with the authors’ concerns about possible bias in industry publishing, we also believe that the exclusion of such research without any analysis of the scientific merits of the research itself precludes a comprehensive assessment of the scientific literature regarding the health risks of ENDS. Also, excluding industry publications necessarily eliminates from consideration evidence that the Center for Tobacco Products may be asked to consider when it is reviewing product applications for product marketing authorizations and modified risk claims.
  The paper falls short, as well, in addressing the risk communication implications of the findings since the authors’ recommendations often do not match the evidence of what is known and not known about the risks of using ENDS. A careful analysis of suggested risk messages contained in supplementary material to the paper finds messages that do not appear to be supported by the evidence reviewed in the paper. For example, the suggested risk messages that "nicotine in vapes can harm memory, concentration, and learning in young people," "vaping nicotine can harm learning ability in young people," and "exposure to nicotine during adolescence can interfere with brain development" do not appear to be derived from a comprehensive review of scientific evidence. The evidence of nicotine having adverse effects on brain development or learning in adolescents comes primarily from rodent studies where dosing of nicotine is not necessarily analogous to exposure from ENDS.
  For most of the topics reviewed, the umbrella review reveals that the health risks of ENDS remain unsettled at this time. Whilst biomarker exposure data clearly indicate reduced risk compared to tobacco cigarettes (4), we would suggest restraint is needed in communicating absolute risk information to the public (7). Also we would go one step further in noting that whatever the health risks of ENDS may be, they are going to be most observable in those persons using ENDS on a persistent basis for months or years at a minimum. For example, the health risks of cigarette smoking do not reliably emerge until after smokers exceed 10 pack-years or more of exposure (87). Few studies of ENDS health risks have actually focused on the likely higher risk group of persistent ENDS users (4).
  We also take issue with the paper’s main conclusion that direct comparison between the harms of cigarettes and ENDS should be avoided (1). In fact, such comparisons are likely unavoidable and necessary since the group most likely to use ENDS on a persistent basis are those who have a history of cigarette use. Moreover, ENDS were originally developed as a cessation aid and evaluations of cessation aids almost always incorporate evidence on the relative harms compared to continuing to smoke. We do recognize that accounting for a person’s smoking history complicates evaluations of the health risks of ENDS, but dismissing such comparisons simply ignores the fact that ENDS are existing or potential cigarette substitutes for many smokers (4, 5). A recent review of biomarker studies found that compared to smoking, using ENDS leads to a substantial reduction in biomarkers of toxicant exposure associated with cigarette smoking, while also acknowledging that the degree of any residual risk from smoking remains unclear because of the lack of comparisons between long-term former smokers, and with those who have never smoked or used ENDS (4).
  Communicating health risk information about ENDS has to have some context to be meaningful to consumers. A common misconception about tobacco use is that the most dangerous component of the product is nicotine (9-14). However, while nicotine can be addictive, it is the other toxicants in tobacco, especially burned tobacco, that are the true culprits of tobacco-related diseases (2, 4). Thus, when communicating information about the health risks of tobacco products, it makes sense to provide consumers with information about the relative health dangers from burned compared to unburned tobacco products. The example risk messages included in the supplementary materials to the paper appear to be developed with a goal of discouraging anyone from using a vaping product rather than to inform potential users about risks.
  Public health authorities can reduce the risk of misinforming or confusing the public by acknowledging when evidence is incomplete or based on statistical association rather than clear evidence of causality, and by updating any statements or recommendations quickly when plausibly causal evidence becomes available (7).

   
  References
  1. Asfar T, Jebai R, Li W, et al. Risk and safety profile of electronic nicotine delivery systems (ENDS): an umbrella review to inform ENDS health communication strategies. Tob Control Epub ahead of print: [please include Day Month Year]. doi:10.1136/ tobaccocontrol-2022-057495
  2. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Board on Population Health and Public Health Practice; Committee on the Review of the Health Effects of Electronic Nicotine Delivery Systems. Public Health Consequences of E-Cigarettes. Eaton DL, Kwan LY, Stratton K, editors. Washington (DC): National Academies Press (US); 2018 Jan 23.
  3. Kim S, Shiffman S, Sembower MA. US adult smokers' perceived relative risk on ENDS and its effects on their transitions between cigarettes and ENDS. BMC Public Health. 2022 Sep 19;22(1):1771. doi: 10.1186/s12889-022-14168-8.
  4. McNeill, A, Simonavičius, E, Brose, LS, Taylor, E, East, K, Zuikova, E, Calder, R and Robson, D (2022). Nicotine vaping in England: an evidence update including health risks and perceptions, September 2022. A report commissioned by the Office for Health Improvement and Disparities. London: Office for Health Improvement and Disparities.
  5. Balfour DJK, Benowitz NL, Colby SM, Hatsukami DK, Lando HA, Leischow SJ, Lerman C, Mermelstein RJ, Niaura R, Perkins KA, Pomerleau OF, Rigotti NA, Swan GE, Warner KE, West R. Balancing Consideration of the Risks and Benefits of E-Cigarettes. Am J Public Health. 2021 Sep;111(9):1661-1672.
  6. Rime Jebai, Wei Li, Oluwole Olusanya Joshua, Beck Graefe, Celia Rubio. Systematic Review of Reviews on the Harmful Effects of Electronic Nicotine Delivery Systems: Building Evidence for Health Communication Messaging. PROSPERO 2021 CRD42021241630 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021241630
  7. United States Surgeon General. Confronting Health Misinformation: The U.S. Surgeon General’ s Advisory on Building a Healthy Information Environment [Internet]. 2021 [cited 2022 Aug 9]. Available from: https://www.hhs.gov/sites/default/files/surgeon-general-misinformation-a...
  8. Doll R, Peto R, Boreham J, Sutherland I. Mortality from cancer in relation to smoking: 50 years observations on British doctors. Br J Cancer. 2005 Feb 14;92(3):426-9. doi: 10.1038/sj.bjc.6602359.
  9. O’Brien EK, Nguyen AB, Persoskie A, Hoffman AC. U.S. adults’ addiction and harm beliefs about nicotine and low nicotine cigarettes. Prev Med. 2017;96:94-100.
  10. Steinberg MB, Bover-Manderski MT, Wackowski OA, Singh B, Strasser AA, Delnevo CD. Nicotine Risk Misperception Among US Physicians. J Gen Intern Med. 2021, 36(12):3888-3890.
  11. Elton-Marshall T, Driezen P, Fong GT, et al. Adult perceptions of the relative harm of tobacco products and subsequent tobacco product use: Longitudinal findings from waves 1 and 2 of the population assessment of tobacco and health (PATH) study. Addict Behav. doi:10.1016/j.addbeh.2020.106337.
  12. Parker MA, Villanti AC, Quisenberry AJ, Stanton CA, et al. Tobacco Product Harm Perceptions and New Use. Pediatrics. 2018 Dec;142(6):e20181505. doi: 10.1542/peds.2018-1505.
  13. Yong HH, Gravely S, Borland R, Gartner C, et al. Perceptions of the Harmfulness of Nicotine Replacement Therapy and Nicotine Vaping Products as Compared to Cigarettes Influence Their Use as an Aid for Smoking Cessation? Findings from the ITC Four Country Smoking and Vaping Surveys. Nicotine Tob Res. 2022 Aug 6;24(9):1413-1421. doi: 10.1093/ntr/ntac087.
  14. National Cancer Institute. Health Information National Trends Survey. HINTS 5 cycle 3, 2019. Available at: https://hints.cancer.gov/view-questions-topics/question-details.aspx?PK_...

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  Conflict of Interest:
  None declared.

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