Ann McNeill and colleagues reply to Martin McKee and Simon CapewellBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h5010 (Published 24 September 2015) Cite this as: BMJ 2015;351:h5010
All rapid responses
We read with interest the letter (1) by McNeill and colleagues regarding McKee and Capewell’s response (2) to the Public Health England evidence update on e-cigarettes. Although the issues debated are contentious and McNeill stated that they found McKee and Capewell’s response offensive, we as Public Health colleagues all essentially want to achieve the same goal. That is, better health for our population. We would like to encourage people to stop-smoking, without increasing other health-risks as much as possible. McNeill states in the response that ‘discouraging smokers from using e-cigarettes (ECs) is irresponsible, however much the safe sounding “precautionary principle” is invoked.’ Yet, McKee and Capewell in their own response agreed that ECs are safer than combustible cigarettes and this is not in dispute.
We agree that the issue is not whether ECs are better than combustible products, but rather that appropriate safeguards must be installed in order to prevent people from using ECs in ways other than their intended purpose as an aid to smoking cessation. For this reason, we would like to reiterate our argument for the safe sounding “precautionary principle”. The evidence base is evolving constantly and that is why a cautious approach to the way that ECs are regulated, advertised and recommended within society is necessary to protect the health of the nation.
A paper in the recent issue of Pediatrics (3) found that ECs are being used by high school children to vaporise cannabis. In the USA, EC use had tripled among high school students from 4.5% in 2013 to 13.4% in 2014 and is now surpassing all other tobacco use. It has become apparent that ECs can be modiﬁed to provide an efﬁcient way to vaporise cannabis in the form of highly concentrated liquid hash oil, highly concentrated waxy forms of ∆-9- tetrahydrocannabinol (THC) or dried cannabis buds or leaves. THC is the primary psychoactive ingredient in cannabis and when it is vaporised, is present at concentrations 4 to 30 times that of dried cannabis. Vaporising cannabis produces a less pungent odour than combustible cannabis and therefore is less conspicuous and harder for police and parents to detect (3).
The authors examined lifetime rates of using ECs to vaporise cannabis in 3847 students from 5 high schools in Connecticut in 2014. The mean age was 16 years and 51.7% were female. 27.9% of the total sample had tried e-cigarettes and 29.2% of the total sample had tried marijuana/hashish. They found that 5.4% of the total sample had used ECs to vaporise cannabis and 18% of those who had used ECs had used them to vaporise cannabis. Lifetime EC users, lifetime cannabis users, male students, and younger students were more likely to use ECs to vaporise cannabis than their respective counterparts were.
This study was based in a small number of schools in Connecticut, United States, and may not be generalizable to the UK. However, it does demonstrate that ECs are being used to vaporise cannabis and there is evidence emerging that using cannabis in this form causes greater subjective tolerance and dependence (4), which is most likely due to the increased concentration of THC. There is a potential for an increase in cannabis vaporisation with increasing use of ECs.
Finally, it is notable that the U.S. Preventive Services Task Force (USPSTF) (5), after reviewing the evidence for EC use for smoking cessation, found only 2 randomised control trials that evaluated the effect of ECs on smoking abstinence in adults and found mixed results. Overall, the USPSTF found the evidence on the use of Electronic Nicotine Delivery System as a smoking cessation tool in adults, including pregnant women, and adolescents to be insufﬁcient and did not recommend the use of ECs as a smoking cessation tool.
In summary, smoking cessation is an essential part of improving the health of the nation, but the plea for caution in the regulation and recommendation of ECs and how they are portrayed to the public remains.
1. McNeill, A. (2015) Ann McNeill and colleagues reply to Martin McKee and Simon Capewell. British Medical Journal, Vol. 351. doi: http://dx.doi.org/10.1136/bmj.h5010
2. McKee, M. and Capewell, S. (2015) Electronic cigarettes: we need evidence, not opinions. The Lancet, Vol. 386. doi: http://dx.doi.org/10.1016/S0140-6736(15)00146-4
3. Morean, M. E., Kong, G., Camenga, D. R., Cavallo, D. A. and Krishnan-Sarin, S. (2015) High School Students' Use of Electronic Cigarettes to Vaporize Cannabis. Pediatrics, Vol. 136. doi: 10.1542/peds.2015-1727 http://pediatrics.aappublications.org/content/early/2015/09/01/peds.2015...
4. Loflin, M. and Earleywine, M. (2014) A new method of cannabis ingestion: the dangers of dabs? Addict Behav., Vol. 39, pp. 1430-1433.
5. Siu, A. L. (2015) Behavioral and Pharmacotherapy Interventions for Tobacco Smoking Cessation in Adults, Including Pregnant Women: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine, Vol. 163 (8), doi:10.7326/M15-2023 http://annals.org/data/Journals/AIM/0/0000605-201510200-00450.pdf
Disclaimer: The views expressed above are solely those of the authors in their private capacity and do not in any way represent the views of Suffolk County Council.
Dr Eleanor Joy Delport, Foundation Year 2 Doctor,
Dr Padmanabhan Badrinath, Consultant in Public Health Medicine
Public Health Suffolk, Suffolk County Council, Endeavour House, Ipswich, IP1 2BX, UK
Competing interests: No competing interests