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Association between electronic cigarette use and changes in quit attempts, success of quit attempts, use of smoking cessation pharmacotherapy, and use of stop smoking services in England: time series analysis of population trends

BMJ 2016; 354 doi: https://doi.org/10.1136/bmj.i4645 (Published 13 September 2016) Cite this as: BMJ 2016;354:i4645

Quality in Research on Electronic Cigarettes:

There is a substantial body of evidence that electronic cigarettes are significantly safer than tobacco smoking. Of course estimates will differ as to exactly how much safer, but few now claim that electronic cigarettes offer anything close to the risks to health inherent in traditional cigarettes, cigars and other forms of combustible tobacco use (eg: Public Health England, 2016).

The study by Beard et al (2016) adds to this literature by highlighting how increases in population use of e-cigarettes also pose no risk in relation to undermining smoking cessation attempts. Indeed, the data suggests a positive association with successful quitting.

Despite this evidence, there remains a significant section of the clinical and academic health community that view electronic cigarettes negatively. The view is reinforced by research often characterised by one (or more) of the following fundamental flaws.

IGNORING RELATIVE RISK
A large amount of research is carried out on the potential risks of electronic cigarettes without comparison to the corresponding risk associated with tobacco smoking. Studies include those that collect case reports of injuries or deaths ‘caused by’ electronic cigarettes (eg: Hue & Talbot, 2016) or lab studies examining physiological changes (usually in mice) after exposure to vapour (eg: Lauterstein et al. 2016). By avoiding any comparison with tobacco smoking, these studies are able to focus attention on the ‘risks’ of electronic cigarettes (no matter how small) and away from their potential for significant risk reduction.

IMPLYING CAUSATION FROM ASSOCIATION
This approach takes advantage of the fact that many factors linked with poorer health outcomes are also associated with (but clearly not caused by) electronic cigarette use. These factors include risk taking behaviour (in an effort to prove that electronic cigarette use ‘causes’ young people to smoke tobacco) and, most recently, alcohol use (Hershberger et al. 2016). The latter study unsurprisingly found that use of electronic cigarette to quit smoking (as opposed to not using electronic cigarettes to quit) was associated with higher alcohol use. This is probably because those choosing to seek to alleviate nicotine cravings with electronic cigarettes would have been higher in nicotine dependence (which in turn is associated with increased alcohol use (Dierker et al 2016). The authors ignored this explanation, however, and boldly claimed in their study title that “Transitioning From Cigarettes to Electronic Cigarettes Increases Alcohol Consumption”.

LABELLING ELECTRONIC CIGARETTES AS ‘TOBACCO’ PRODUCTS
This approach simply involves including electronic cigarettes within products collectively referred to as ‘tobacco products’ despite the fact that they contain no tobacco. A recent example is the study by England et al. (2016) who include electronic cigarettes within a group of “emerging tobacco products”. This link is made in the title and the very first line of the abstract, and as such clearly sets up a spurious association in the mind of the reader between electronic cigarettes and the well-established dangers inherent in tobacco.

The approaches to research described above arguably represent a pattern that has the potential to do harm. If the general public are to come to an informed decision on electronic cigarettes then they require evidence that is balanced, robust and accurate. It is surely incumbent on researchers, as well as research sponsors and academic journal editors to ensure that standards are maintained in this crucial area of work.

References
Beard, West, Michie & Brown (2016) Association between electronic cigarette use and changes in quit attempts, success of quit attempts, use of smoking cessation pharmacotherapy, and use of stop smoking services in England: time series analysis of population trends. BMJ 2016;354:i4645

Dierker, Selya, Rose, Hedeker & Mermelstein (2016). Nicotine Dependence and Alcohol Problems from Adolescence to Young Adulthood. Dual Diagn (Foster City). 2016;1(2).

England,Tong, Koblitz, Kish-Doto, Lynch &, Southwell (2016). Perceptions of emerging tobacco products and nicotine replacement therapy among pregnant women and women planning a pregnancy. Prev Med Rep. 2016 Sep 7;4:481-5.

Hershberger, VanderVeen, Karyadi & Cyders (2016) Transitioning From Cigarettes to Electronic Cigarettes Increases Alcohol Consumption. Subst Use Misuse. 2016 Dec 5;51(14):1838-45

Hue & Talbot (2016) Potential health effects of electronic cigarettes: A systematic review of case reports. Prev Med Rep. 2016 Dec; 4: 169–178.

Lauterstein, Tijerina, Corbett, Oksuz,. Shen, Gordon, Klein, & Zelikoff (2016) Frontal Cortex Transcriptome Analysis of Mice Exposed to Electronic Cigarettes During Early Life Stages Int J Environ Res Public Health. 2016 Apr; 13(4): 417.

Public Health England (2015) E-cigarettes: an evidence update. https://www.gov.uk/government/publications/e-cigarettes-an-evidence-update

Competing interests: No competing interests

28 September 2016
Lisa McNally
Consultant in Public Health
Market Street, Bracknell RG12 1JD