Professor Chapman’s criticism of Cochrane review findings is deeply flawed
Posted on December 12, 2022 By Colin
COCHRANE REVIEWS ARE THE GOLD STANDARD for determining if a treatment is effective in randomised controlled trials (RCTs). [1] The recent Cochrane review on e-cigarettes found high certainty evidence that vaping help peoples quit smoking better than traditional nicotine replacement therapies (NRTs). [2]
This my response published today in Australian Doctor here.
In his recent interview with Australian Doctor (‘Why Cochrane got it badly wrong: Aussie expert unpicks ‘pro-vaping’ review‘), Professor Chapman dismissed the Cochrane review for not reflecting real world behaviour.
This misunderstands the role of RCTs, which is to find if a treatment works in motivated smokers in a controlled environment
Abundant evidence now also exists showing that vaping works in the real world setting, from UK Stop Smoking Services [3], observational studies [4-6], population studies [7, 8] and declines in national smoking rates [9-11]. While these studies cannot prove causality, their results are consistent with the Cochrane findings.
Longitudinal studies
Professor Chapman refers to longitudinal studies from the US PATH cohort showing very little benefit from vaping. However, these studies typically include vapers not wanting to quit and those vaping occasionally.
Motivated quitters who vape daily have substantially increased quit rates. One PATH study of over 32,000 subjects found that daily vaping increased quit rates by 8 times compared to using other quit methods. [12]
Many other longitudinal studies have found that vaping is effective and that daily vaping increases quit rates by 2-8 times. [12-14]
Population studies in the UK, US and New Zealand have found that smoking rates have declined faster since vaping became widely available. [8, 11, 15] The recent report from the Office of National Statistics in the UK concluded that “Vaping devices such as e-cigarettes have played a major role in the decrease in smoking prevalence in the UK”. [10]
Long-term safety
Professor Chapman is concerned about the lack of evidence for long-term safety. However, leading health and government organisations, such as the Royal College of Physicians [16] and the New Zealand Ministry of Health [15], have concluded that,
while the long-term harm of using e-cigarettes will not be fully known for many decades, it is highly likely to be far less than smoking, which prematurely kills up to 2 in 3 continuing smokers. [17]
This is to be expected. A dose-response relationship exists between exposure to toxicants from smoking and disease risk and the same is likely for vaping. [18] There are substantially fewer toxicants in vapour than in smoke and those present are in much lower doses. [19-21] There are also a dramatic reduction of biomarkers of harm in the blood and urine of vapers after switching [17].
Clinical trials have shown improvements in asthma [22], COPD [23], blood pressure [24, 25], muco-ciliary clearance [26], respiratory infections [27], lung function [28], respiratory symptoms [29, 30], cardiovascular markers [31, 32] and gum disease.[33] These changes are in the direction of less impairment and are likely to persist over the longer term.
In the absence of long-term data, modelling studies are a well-accepted way of estimating the population impact of an intervention. Numerous modelling studies suggest that nicotine e-cigarettes are likely to have a net positive public health benefit under all plausible scenarios. [34-36]
Australia’s prescription-only model
Professor Chapman claims that every public health agency wants to continue with the prescription model. This is true in Australia. However, every other western country has rejected this approach and all follow the consumer model.
Australia’s prescription-only model has been a resounding failure. The regulations were intended to prevent youth vaping and to allow access for adult smokers as a smoking cessation aid.
Predictably, it has had the opposite effect. It has been rejected by GPs, vapers and pharmacists
Only 373 doctors are listed publicly as nicotine prescribers [37] and less than 10% of Australia’s 1.1 million vapers have a prescription. [38] Only a handful of pharmacies dispense nicotine liquid.
The prescription model has also created a thriving black market selling illegal, unregulated vaping products from tobacconists, convenience stores, online and on social media. These devices are freely sold to young people and have created legitimate concerns about youth vaping.
The only way to eliminate an illicit market is to replace it with a legal and regulated one. Nicotine liquid should be an adult consumer product, sold from licensed retail outlets such as vape shops, convenience stores, tobacconists and general stores where tobacco is sold.
There should be strict age-verification and severe penalties and loss of licence for under-age sales, with strict enforcement.
After 18 months, Australia’s experiment has failed. We need to bring vaping policy into line with all other western countries. Without a workable regulatory pathway enabling access by the adult smokers who need vapes, whilst restricting access by young people, more smokers will die unnecessarily leading to disastrous public health outcomes in the coming years.
Dr Mendelsohn is the founding chairman of the Australian Tobacco Harm Reduction Association, which promotes vaping as an alternative to those unable or unwilling to quit smoking.
References
1. Spurling G, Mitchell B, van Driel ML. Unlocking the value of Cochrane reviews for general practitioners. Aust J Gen Pract. 2018;47(6):333-6.
2. Hartmann-Boyce J, Lindson N, McRobbie H, Butler AR, Bullen C, Begh R, et al. Electronic cigarettes for smoking cessation. Cochrane Database of Systematic Reviews; 2022.; 2022. [accessed 2022 November 19]. Available from: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD010216.pub7/full
3. McNeill A, Simonavicius E, Brose LS, Taylor E, East K, Kuilova E, et al. 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. 2022. [accessed 2022 Nov 7]. Available from: https://www.gov.uk/government/publications/nicotine-vaping-in-england-2022-evidence-update
4. Goldenson NI, Shiffman S, Hatcher C, Lamichhane D, Gaggar A, Le GM, et al. Switching away from Cigarettes across 12 Months among Adult Smokers Purchasing the JUUL System. Am J Health Behav. 2021;45(3):443-63.
5. Adriaens K, Belmans E, Van Gucht D, Baeyens F. Electronic cigarettes in standard smoking cessation treatment by tobacco counselors in Flanders: E-cigarette users show similar if not higher quit rates as those using commonly recommended smoking cessation aids. Harm Reduct J. 2021;18(1):28.
6. Kotz D, Jackson S, Brown J, Kastaun S. The Effectiveness of E-Cigarettes for Smoking Cessation. Dtsch Arztebl Int. 2022;119(17):297-301.
7. Chambers MS. Effect of vaping on past-year smoking cessation success of Australians in 2019-evidence from a national survey. Addiction. 2022;117(8):2306-15.
8. Zhu SH, Zhuang YL, Wong S, Cummins SE, Tedeschi GJ. E-cigarette use and associated changes in population smoking cessation: evidence from US current population surveys. BMJ. 2017;358:j3262.
9. National Center for Health Statistics. Percentage of current cigarette smoking for adults aged 18 and over, United States, 2019 Q1, Jan-Mar—2022 Q1, Jan-Mar. National Health Interview Survey.; 2022. [accessed 2022 Nov 7]. Available from: https://wwwn.cdc.gov/NHISDataQueryTool/ER_Quarterly/index_quarterly.html
10. Office of National Statistics. Adult smoking habits in England. 2021. [accessed 2022 Nov 7]. Available from: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/healthandlifeexpectancies/datasets/adultsmokinghabitsinengland
11. Fagerström K. Can alternative nicotine products put the final nail in the smoking coffin? Harm Reduct J. 2022;19(1):131.
12. Berry KM, Reynolds LM, Collins JM, Siegel MB, Fetterman JL, Hamburg NM, et al. E-cigarette initiation and associated changes in smoking cessation and reduction: the Population Assessment of Tobacco and Health Study, 2013-2015. Tob Control. 2018;28(1):42-9.
13. Giovenco DP, Delnevo CD. Prevalence of population smoking cessation by electronic cigarette use status in a national sample of recent smokers. Addict Behav. 2017;76:129-34.
14. Biener L, Hargraves JL. A longitudinal study of electronic cigarette use among a population-based sample of adult smokers: association with smoking cessation and motivation to quit. Nicotine Tob Res. 2015;17(2):127-33.
15. Ministry of Health New Zealand. New Zealand Health Survey 2021/22. 2022. [accessed 19 November 2022]. Available from: https://www.health.govt.nz/nz-health-statistics/national-collections-and-surveys/surveys/new-zealand-health-survey
16. Royal College of Physicians. Nicotine without smoke: Tobacco harm reduction. London: RCP. 2016 [accessed 2022 Nov 7]. Available from: https://www.rcplondon.ac.uk/projects/outputs/nicotine-without-smoke-tobacco-harm-reduction-0
17. Banks E, Joshy G, Weber MF, Liu B, Grenfell R, Egger S, et al. Tobacco smoking and all-cause mortality in a large Australian cohort study: findings from a mature epidemic with current low smoking prevalence. BMC Med. 2015;13:38.
18. US Department of Health and Human Services. The health consequences of smoking - 50 years of progress. A report of the Surgeon General.; 2014. [accessed 2022 Nov 7]. Available from: https://www.surgeongeneral.gov/library/reports/50-years-of-progress/full-report.pdf
19. Goniewicz ML, Knysak J, Gawron M, Kosmider L, Sobczak A, Kurek J, et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob Control. 2014;23(2):133-9.
20. Margham J, McAdam K, Cunningham A, Porter A, Fiebelkorn S, Mariner D, et al. The Chemical Complexity of e-Cigarette Aerosols Compared With the Smoke From a Tobacco Burning Cigarette. Front Chem. 2021;9:743060.
21. Nicol J, Fraser R, Walker L, Liu C, Murphy J, Proctor CJ. Comprehensive Chemical Characterization of the Aerosol Emissions of a Vaping Product Based on a New Technology. Chem Res Toxicol. 2020;33(3):789-99.
22. Polosa R, Morjaria JB, Caponnetto P, Caruso M, Campagna D, Amaradio MD, et al. Persisting long term benefits of smoking abstinence and reduction in asthmatic smokers who have switched to electronic cigarettes. Discov Med. 2016;21(114):99-108.
23. Polosa R, Morjaria JB, Prosperini U, Busà B, Pennisi A, Malerba M, et al. COPD smokers who switched to e-cigarettes: health outcomes at 5-year follow up. Ther Adv Chronic Dis. 2020;11:2040622320961617.
24. Polosa R, Morjaria JB, Caponnetto P, Battaglia E, Russo C, Ciampi C, et al. Blood Pressure Control in Smokers with Arterial Hypertension Who Switched to Electronic Cigarettes. Int J Environ Res Public Health. 2016;13(11).
25. Farsalinos K, Cibella F, Caponnetto P, Campagna D, Morjaria JB, Battaglia E, et al. Effect of continuous smoking reduction and abstinence on blood pressure and heart rate in smokers switching to electronic cigarettes. Intern Emerg Med. 2016;11(1):85-94.
26. Polosa R, Emma R, Cibella F, Caruso M, Conte G, Benfatto F, et al. Impact of exclusive e-cigarettes and heated tobacco products use on muco-ciliary clearance. Ther Adv Chronic Dis. 2021;12:1-9.
27. Miler J, Mayer B, Hajek P. Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an Online Survey. Journal of Addiction Research & Therapy. 2016;7(4).
28. Cibella F, Campagna D, Caponnetto P, Amaradio MD, Caruso M, Russo C, et al. Lung function and respiratory symptoms in a randomized smoking cessation trial of electronic cigarettes. Clin Sci (Lond). 2016;130(21):1929-37.
29. Hajek P, Phillips-Waller A, Pfzulki D, Pescola F, Myers Smith K, Bisal N, et al. A randomised trial of e-cigarettes versus nicotine replacement therapy. N Engl J Med. 2019;380:629-37.
30. Lucchiari C, Masiero M, Mazzocco K, Veronesi G, Maisonneuve P, Jemos C, et al. Benefits of e-cigarettes in smoking reduction and in pulmonary health among chronic smokers undergoing a lung cancer screening program at 6 months. Addict Behav. 2020;103:106222.
31. George J, Hussain M, Vadiveloo T, Ireland S, Hopkinson P, Struthers AD, et al. Cardiovascular Effects of Switching From Tobacco Cigarettes to Electronic Cigarettes. J Am Coll Cardiol. 2019;74(25):3112-20.
32. Berlowitz JB, Xie W, Harlow AF, Hamburg NM, Blaha MJ, Bhatnagar A, et al. E-Cigarette Use and Risk of Cardiovascular Disease: A Longitudinal Analysis of the PATH Study (2013-2019). Circulation. 2022;145(20):1557-9.
33. Yang I, Sandeep S, Rodriguez J. The oral health impact of electronic cigarette use: a systematic review. Crit Rev Toxicol. 2020;50(2):97-127.
34. Summers JA, Ait Ouakrim D, Wilson N, Blakely T. Updated Health and Cost Impacts of Electronic Nicotine Delivery Systems, Using Recent Estimates of Relative Harm for Vaping Compared to Smoking. Nicotine Tob Res. 2022;24(3):408-12.
35. Levy DT, Tam J, Sanchez-Romero LM, Li Y, Yuan Z, Jeon J, et al. Public health implications of vaping in the USA: the smoking and vaping simulation model. Popul Health Metr. 2021;19(1):19.
36. Mendez D, Warner KE. A Magic Bullet? The Potential Impact of E-Cigarettes on the Toll of Cigarette Smoking. Nicotine Tob Res. 2021;23(4):654-61.
37. Therapeutic Goods Administration. Authorised Prescribers of unapproved nicotine vaping products. 2022. [accessed 19 November 2022]. Available from: https://www.tga.gov.au/resources/resource/guidance/authorised-prescribers-unapproved-nicotine-vaping-products
38. Mendelsohn C. How many adult Australians vape? 2022. [accessed 19 November 2022]. Available from: https://colinmendelsohn.com.au/number/