E-cigarettes are less harmful – the 95% subjective ranking

I have been guilty of being imprecise on twitter – so I’ll elaborate on word press about my concerns with the e-cigs are 95% less harmful than cigarettes figure.

Firstly allow me to be clear – the public health England report on e-cigarettes is an important document that is excellent bar its reference to and use of the 95% figure. The report was needed to address growing irrational and prohibitionist agenda’s which seem to underlie some public health responses to e-cigarettes. This figure was arrived at after a panel of experts subjectively assigned a level of harm based on different criteria to different substances. Professor Larry Phillips, one of the authors of the study explains it on “More or less” and concedes it is a subjective ranking and that is ok because he asserts all other numbers arrived at in science are just as  “subjective”. This is where I disagree strongly. His throwaway comment when you consider it in detail makes a mockery of science to date. While science and the scientific process hasn’t been perfect it has enabled significant progress and is generally more objective than other processes. The process he used IS much more subjective than other studies used in science. Is he qualified to make this sort of pronouncement about the quality of his method relative to others? He isn’t a scientist. Perhaps it reflects his own profession’s tendency for rubbery figures and very speculative estimates (I’m attempting humour here by creating faux scientist versus economist repartee and making a sweeping generalisation). Whilst I acknowledge that any science involving people will have degrees of subjectivity creeping in – by and large there have been processes and methodologies evolved which do help minimise the subjectivity creeping into estimates.

My concern about the 95% figure is due in part to the below mentioned sort of outcome of discussions about it I’ve had with other people.

I’ve asked several friends, colleagues and acquaintances how they think the 95% less harmful figure was derived (these are people who are not scientists, most not involved in health care as professionals). It’s very unlikely they’ll ever question or look in detail at how the 95% figure was actually derived. Their response, prior to me telling them how the number is derived, is fairly consistently that it’s been derived from a study of health outcomes of real people or experiments/studies on the effects on cells etc or animals. When I explain that it was a ranking done by experts, albeit incorporating different categories of harm, they are dismayed and think it is deceptive and an untrustworthy way of presenting the relative harms or lack thereof.

This figure, the way it has been derived and Professor Larry Phillips assertion, I fear, contribute significantly to mistrust and discrediting of science.

Perhaps his method of assessing a complex issue will in time be another robust method for us but it is currently new, untested & the 95% figure is NOT robust or as equally “subjective” as other scientific methods that have had more road testing. It should not have been referred to in a government report which by this action gives the methodology an aura of credibility & rigour it doesn’t warrant.

I also think the Lancet has been disingenuous in it’s criticism of the report. One industry rep on the panel was not the problem and there is much about the report to support.

Thanks very much to Alan, Lorien and some other vapers who I really appreciate having twitter conversations with and who prompted this blog. I love your consistent careful and respectful questioning of my tweets. I appreciate your dedication and think you are a positive force currently in public health.

I probably have much less conflict of interest than most other people on e-cigs. I’m not making money from them, I don’t need to publish on them and I’m not funded to do tobacco control work. I work on vaccines and immunisation now. My Dad died of lung cancer and I hate the thought of many other people suffering in the same way he did.


5 thoughts on “E-cigarettes are less harmful – the 95% subjective ranking

  1. Nice blog… a couple of further points about this…

    1. The academics involved in the review itself (not the Nutt et al MCDA) have been using the “at least 95% lower risk than smoking” formulation since June 2014. It is grounded in the literature examining the toxicology, chemistry and physics of vapour – and the recognition that most toxic constituents of cigarette smoke are either not detectable or present at concentrations well below 1/20th found in cigarette smoke. They discuss this in their reply to the Lancet editorial. http://www.thelancet.com/pb/assets/raw/Lancet/pdfs/S0140673615000793.pdf

    2. If anything their error was to say “about 95% lower” rather than “at least 95% lower and possibly no mortal risk at all” and to give the appearance of relying on the Nutt analysis, rather than the main reviews of the wider literature and drawing their own expert view. These reviews include:

    3. Many public health people have reacted with indignation at the apparent precision of these number (and I agree the range implied by “at least 95% lower” would be better). However, numbers are widely used in public health risk communication and are always approximations, always carry value laden biases such as an implied risk appetite. Some examples include guidelines for alcohol. salt and sugar consumption… where is the evidence base for these?


    • The real basis for this claim is the absence of harmful agents in the vapour – it is down to chemistry and physics of vapour, not measurements of negative material health impacts, which have so far not been detected. Most informed observers think that a residual 5% of the risk of smoking is excessive (or as PHE would put it) cautious and these products are unlikely to carry any mortal risks – though possibly some risks of chest irritation etc.

  2. Thoughtful analysis, Janine. Thank you. However, as Clive posted above, the 95% figure is highly conservative primarily in light of the overwhelming chemistry and toxicology information. In addition the antis have also been scraping the barrel for 12 years and have so far failed to produce even one single shred of credible evidence with respect to the harms they’ve been hypothesizing for vaping. Put these together, and a risk figure closer to “as safe as breathing purified air” [1] is far more credible than any of the fake concerns emanating from the tax-funded anti-smoker industry.
    [1] http://www.sciencedirect.com/science/article/pii/S0887233315001228

  3. In the 80’s there were many in Public Health who opposed the use of condoms in the fight against HIV/AIDS as they were not deemed 100% safe. Fortunately they were ignored and the numbers of HIV +ve cases started dropping.

    Roll forward 30 years and the same is happening with Ecigs; They are not 100% safe (nothing is, just try drinking 5ltr water in half an hour and see what happens) but they are a SAFER alternative to burning lit tobacco. Public Health (especially in the USA) have pumped millions of dollars into advertising against Ecigs, funding studies that have been proved time and again to be lacking in honesty and truthfulness. Lies, damn lies and statistics. Cherry picking from all over to try and prove their point.

    E cigarettes have been a game changer in the reduction of harm that normal cigarettes cause. The big tobacco and pharma players are scared that their “cash cow” could come to an end and will (are) doing everything in their power to get Ecigs banned, outlawed and demonised without a thought for the health of the people. Many public health professionals are also “cherry picking” data (Japanese report that Ecigs have carcinogens present in larger quantities than normal cigarettes) and misinforming the public. I smoked for 38 years and have been tobacco free for coming up 3 years now and I have not cost the government a penny (except for their lost taxes). I will oppose the banning of Ecigs and flavours for my right to choose a healthier and more enjoyable form of administering nicotine to myself.

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