95% Less Harmful – the Story of a Statistic

When Public Health England (PHE) published their recent report on e cigarettes, the statistic to hit the headlines was the claim that the electronic variety were ‘95% less harmful’ than standard cigarettes. It’s a figure that will have entered the collective consciousness of journalists and vaping enthusiasts, and I can guarantee that we will hear it quoted again and again in coming months and years.

The question is: where has it come from, and what does it mean?

The first question is easy to answer: the 95% figure does not come from PHE. Their report simply quotes the estimates made by another group of experts published by Nutt et al in European Addiction Research. Simply put, PHE have said: ‘other experts have guessed that e cigarettes are 95% less harmful than standard cigarettes, and that seems about right to us.’

The over reliance on the findings of another group of experts has received some very public criticism – most notably in an editorial in The Lancet when it emerged that the findings of this group had been funded by an organisation with links to industry, and that three of its authors had significant financial conflicts of interest. These are valid points, although they may have been made better if The Lancet had included the author’s name and declaration of interests alongside the editorial.

The second question is harder to answer, and here is my main concern with how the 95% figure has been presented. What does ‘95% less harmful’ actually mean?

If I were a smoker, wondering whether to switch to vaping, I would primarily be interested in one thing: how harmful are they to me. In other words – am I less likely to die or get ill if I switch to e cigarettes?

Well, the PHE report would seem to answer this question – in the forward to the full report the authors state that e cigarettes are ‘95% less harmful to your health than smoking.’ The trouble is that the report where they obtained the 95% figure looked at far more than just the effects of smoking on the health of an individual.

The piece of work by Nutt and colleagues involved a group of experts being asked to estimate the harm of a range of nicotine products against 12 different criteria – these included the risk to individual health, but also other societal harms such as economic impact, international damage and links with crime. The 95% figure was only achieved after all 12 factors were weighted for importance and then each nicotine containing product was given a composite score.

Now the propensity for a commercial product to be linked with criminal activity may be very important to PHE, but it wouldn’t influence my individual health choice, nor the advice I would want to give to patients.

Moreover, the work by Nutt and colleagues includes this statement: ‘Perhaps not surprisingly, given their massively greater use as compared with other products, cigarettes were ranked the most harmful.’ So the research was greatly influenced by the extent to which products are used. On this basis you could conclude that drinking wine is more harmful than drinking methylated spirits – on a population basis this is true, but it would be a poor basis for individual advice. 

In response to the criticism in The Lancet, PHE produced a subsequent statement in order to try to achieve some clarity over the 95% figure – only to muddy the waters further by claiming that the figure was linked to the fact that there are 95% fewer harmful chemicals in e cigarettes than standard cigarettes. This may well be true – but it is not the reason why they gave the 95% figure in the first place. It also assumes a linear relationship between the amount of chemical and the degree of harm – 5% of the chemical might only cause 1% of the harm, or it could be 50%.

One of the main problems I have with the 95% statistic, therefore, is one of principle – I just don’t like being duped by the misuse of statistics.

My second issue, however, is more pragmatic: the statistic does not help us with some of the key questions we need to answer.

That e cigarettes are safer than standard cigarettes is not much in doubt – mostly on the basis that smoking is so bad for health that it isn’t hard to beat. There is clearly much to be gained by smokers switching to the electronic variety. The next question concerns what smokers should do next.

Much is said about e cigarettes being an aid to quitting, but what is unique about them is that people often stay with them for the longterm, in a way that they would never consider with something like a nicotine patch. This may be their greatest strength – people may be able to quit who could never do so before – but it is also a new phenomenon as longterm nicotine substitution becomes the norm.

Are e cigarettes so safe that once smokers move over to them they can consider the job done? Many vapers talk about it in these terms. For the short term, it seems they are safe. They have been in common use for 5-8 years and there have been no major concerns so far (although acute poisoning is a new problem with liquid nicotine) – but then the same is true for cigarettes where it is use over decades that is the problem. For me, the 95% figure is too questionable to be able to help here.

There are more dilemmas I face as a doctor since I need to know how to interpret the health risks of someone who uses an electronic cigarette. When it comes to cardiovascular risk, should I consider them a smoker, a non-smoker, or something in between? If they have a persistent cough, do I suggest a chest x-ray early on the grounds that they are at increased risk, or can we watch and wait for a while?

We are a long way from being able to answer questions like this, and I would have preferred a little more honesty from PHE about what we don’t yet know, a little less reliance on the opinions of experts, and only to be presented with a figure like 95% if it is based on hard, objective evidence.

I haven’t Been Paid to Write This

There were two items in the news last week that created an interesting juxtaposition on the issue of transparency.

The first concerned the new guidelines for Vloggers – those entrepreneurial YouTubers who have managed to create a following by recording short video clips of their lives, hoping to earn a few pounds along the way.

Some, it seems, have been earning extra money by being paid to recommend products to their viewers – Oreo biscuits being the most high profile example – and such is their influence that new rules have been established to make sure the unsuspecting public know money has changed hands. In short, they can recommend anything they like, but must make a clear declaration if they’ve been paid to do so.

The BBC news cheerfully put together item where three young female Vloggers dutifully explained the new rules, gaining some useful exposure for their own YouTube channel along the way.

You can hardly object to the rules; transparency is important and the consuming public should not be misled.  These young women hardly seemed to be a major threat to society, though, and you couldn’t help thinking that the establishment had come down hard on some enterprising young people who had found a way to start saving for a mortgage.

The second item concerned e cigarettes. Public Health England had produced a report stating that e cigarettes are ‘95% less harmful’ than standard cigarettes and suggesting that they should be prescribed on the NHS in the future.

The report is not a new study, but the opinion of a group of experts who have looked at all the evidence that is out there and given us the benefit of their combined wisdom.

Now, when a Vlogger declares one brand of biscuit to be superior to another, we have a right to know whether or not they have any financial incentive to say so; as Shahriar Coupal, director of the Committee of Advertising Practice says: ‘it’s simply not fair if we’re being advertised to and are not made aware of that fact.’

So what if a scientific expert declares one type of cigarette to be safer than another? Do we not have the same right to know whether the expert has had any financial dealings with the makers of cigarettes? Good medical practice would certainly say so, but the practical reality is often very different.

I have looked at the report in detail. The names of the authors are clear, but nowhere in its 111 pages can I find any declaration of interests; I have no way of knowing whether or not these authors have been paid by the makers of e cigarettes.

Which is more important? The type of biscuit someone may buy after watching a video on YouTube, or the health advice given to the nation by Public Health England on something as topical as e cigarettes?

I’m not stating that the authors do have any conflict of interests – they may well be entirely free from such ties – but the issue is that I cannot tell. If they have no such links, then tell me – I will be far more willing to trust the opinion of these experts if that is the case. If, on the other hand, they have received money from industry, then I have both a right and a need to know – for the sake of my patients and the advice I may pass on to them.

The authors may have made declarations of interests elsewhere, but this is no good to me since I don’t know where to look, and anyway, why should I be required to hunt for them? The Vloggers have to make a declaration on the page where they advertise the product, it should be no different for Public Health England.

Why are these declarations so often absent in reports like this? Is it thoughtlessness, laziness, or something more sinister? I don’t know, but it should be different. We need a culture change until it becomes unthinkable to publish such a report without them. We need a media that will focus the story on the lack of such a declaration rather than on the report itself – which is, after all, meaningless without it.

So what do I think of the report itself? Sadly, until I know if I can trust its authors I just don’t think I can make a judgement.


As you will be able to see from the comments below, Public Health England have amended the report to include full DOI on pages 90 and 91 which is great news!

Plain Cigarette Packaging – Does the Government Really Care About Health?

So today is the Queen’s Speech, and the promised legislation on plain packaging for cigarettes has been shelved – put on hold, maybe, hopefully, but probably left to flounder in the long grass until it is somebody else’s problem.

I have no doubt that it takes great courage to take on the might of the tobacco industry – but Australia has paved the way for the rest of the world to follow, it has taken the hit of lengthy legal battles and proved victorious. Our own Government just needs to follow in this lead, and that it has refused to do so does not show a lack of political mettle, but a fundamental problem with political ideology: When it comes to the health of the nation or the health of business, business wins every time.


This decision makes a mockery of Government rhetoric on health – promises such as:

These are worthy goals, and it is good to hear the Government talking about them – but they have shown no willingness to play their part in tackling these problems. All of these health outcomes are closely linked to smoking. In response to a recent report on international mortality data, Jeremy Hunt derided the UK health service for ‘shocking underperformance.’

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers – cancer, heart disease, stroke, respiratory and liver diseases. He will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year.

I have blogged my views on this report, and Hunt’s response to it, elsewhere, and so won’t repeat them here. It is not good enough, however, to tell local health commissioners to do better if the Government is not willing to play its part. Many of the biggest health benefits in the history of medicine have come in the area of public health – vaccination, health and safety at work, sanitation and the smoking ban to name a few. Plain packaging could have been the next big public health policy to have an impact. I don’t believe anyone thinks it would be bad for the health of our nation to move to plain packaging; undoubtedly most smokers won’t care what the packet looks like, but it is hardly likely to increase smoking rates.

There are arguments being made against, of course – from the ludicrous notion that small shops will implode because of the extra time it might take shop-keepers to find the right packet, to more reasonable concerns about job losses and counterfeit packets. Suzie Gage has looked at the (lack of) evidence for some of these claims – and as for job losses, well wouldn’t that apply to any strategy to reduce smoking? What should really worry us are the conflicts of interest behind the scenes that may be influencing decisions – like ministers enjoying hospitality from tobacco companies and lobbyists failing to declare their links to the industry.

Instead of doing what it can to prevent disease in the first place, the Government prefers that we wait for it to happen, and then catch it in its earliest stages through screening. This is the thinking behind the NHS Health Check (about which I have blogged here), a hugely expensive programme which may have benefits for a few individual, but where the evidence that it will improve the health of a population is very limited indeed.

And the most frustrating aspect of the whole thing is that the Government’s favoured statistic for measuring our health will actually be best improved by encouraging smoking and then screening for disease. Again, I have already blogged about the unhealthy obsession with 5 year survival data. The truth is that you don’t improve 5 year survival by reducing the number of smokers – because you can’t survive something like lung cancer if you don’t get it in the first place. No, far better to keep people smoking, scare them about cancer enough so that they undertake one of our screening programmes and then cure them – that way we can really make a difference to the statistics and give ourselves a lovely congratulatory slap on the back.

To patch or not to patch? The latest on Nicotine Replacement Therapy

It is an inevitable consequence of the headline-driven world we live in that the newsworthiness of any health story will always be measured by its ability to generate a good strap line on a popular subject with a high level of public interest, rather than its actual value to the health of the nation. I can’t say that I mind this – as someone who enjoys a catchy headline as much as anyone I suspect it would be terribly dull if it were not so.

Nevertheless, the inevitable consequence of this approach is to elevate some stories somewhat above their station, as was the case with last weekend’s headline: ‘Nicotine patches no better than will power to quit smoking‘. I can’t blame the Daily Telegraph for this somewhat misleading conclusion – after all, the Today Programme on Radio 4 said much the same thing, and it is rather more attention grabbing than ‘Ex-smokers relapse at the same rate regardless of how they quit’, or even ‘quite a lot of people who have recently quit smoking actually succeed’ – both of which are more true to the facts, but would never help me to get a job in journalism.

The reports related to a study on the outcomes for people in the USA who had recently quit smoking which was published recently in the Journal Tobacco Control. I have no problems with the paper – it is well conducted study with honest intentions, and has added something to our understanding of smoking relapse. It does not, however, tell us about whether or not nicotine patches help smokers to quit – since it only looked at relapse rates of those who have already quit, either with the help of Nicotine Replacement Therapy (NRT) or without it.

The researchers conducted telephone interviews in 2001-2002 to make contact with 4991 people who were current smokers, recent quitters (those who had quit in the last 2 years) and young adults (who were thought more likely to take up smoking). They then phoned these people again at 2 and 4 years to review about their smoking habits. Of those who managed to quit, about 30% had started again at 2 years, and a further 30% of the remainder had started again at 4 years. Put it another way, 70% were not smoking at 2 years and 70% (so 49% of the original number) of these were still not smoking at 4 years – good for them! If 50% of people who manage to stop smoking are still ex-smokers at 4 years that is something to celebrate in my book.

The study then went on to look at any factors that might predict why a person would relapse – age, sex, ethnicity, educational attainment, level of smoking, duration of quitting at the time of the research and use of NRT were all studied. The problem with looking at so many variables is that the numbers start to get quite small when you break it down – so there were only just over 50 users of NRT in the entire study (compared with over 400 who had quit without using NRT). They found that the only factor that could predict whether or not someone might relapse was if they had already quit for longer then 6 months – when relapse fell from the baseline of 30% to around 17%, a figure that reached statistical significance.

So, if you quit using NRT then this (now quite small) study suggests that you are no less likely to relapse than someone who has not used NRT. Well that is not a finding that knocks me over! Why would we expect NRT to make a difference to relapse rates months later? There is no reason for it to have a prolonged effect – the key question is, does it make you more likely to quit in the first place? If I am twice as likely to quit by using NRT and I have the same relapse rate, then I am still twice as likely to become an ex-smoker in the long term. If NRT had double the relapse rate then we might have a problem, but that is not what this research has shown.

The considered opinion on the effectiveness of NRT from the meta-analyses of all the Randomised Controlled Trials (the major ones of which are actually quoted in this paper) is that the quit rate with NRT is somewhere between 1.5 and 3.1 times the rate with placebo. So NRT does work. It might not suit everyone, and is no substitute for a good dose of will power, but we should not throw it out of the smoker’s armoury just yet.

The right not to be lectured to

I recognise the signs now. They vary, of course. Sometimes it is the slight drop of the shoulders, the hangdog expression, the look of learned helplessness and defeat. Or it might be the just opposite – the set jaw and steely look in the eye that says: ‘Go on, then! Just you try, I’m ready for you!’

It usually happens in the second half of the consultation. We have talked about the problem, looked at the offending body part that has caused the symptoms and begun to skirt around the cause or hint at solutions, but we both know it is coming. There is no way around it – we are going to have to talk about weight. The best thing we can do is get it over with as quickly and as painlessly as possible.

I feel for my overweight patients. You can lie to me about how much you drink and admit to only half the cigarettes you smoke. You can even claim to actually get your money’s worth from your gym subscription and I will happily believe you, but you cannot leave your weight at home when you visit me or pretend it isn’t there. You know your heartburn/diabetes/foot pain/arthritis is largely down to your weight and all you can do is steel yourself for a lecture while you sit in the waiting room.

And now the Government tells me we have to have this conversation every time you come to see me.  You might come about a cough, a cold or a wart on your finger and I am to talk to you about your weight. Burst into tears with depression,    troubled with your periods, stressed at work or worried about your elderly demented mother – if it looks like you might tip my scales then I am to make every contact count and talk about your weight. And while we are at it, what about your smoking, drinking and that underused gym subscription…?

The Government has accepted in full the recommendations of the NHS Future Forum which includes the concept of making every contact count – that all health professionals, whether GPs, pharmacists, dentists, nurses or anyone else that has a professional contact with patients, should promote healthy lifestyle measures every time they see someone, whatever the reason for the contact. What is more, the recommendation is that: ‘To emphasise the importance of this responsibility, the Secretary of State should seek to include it in the NHS Constitution.’

The NHS Constitution is a list of the rights and responsibilities of patients and professionals with respect to the NHS. It is an important and helpful document that shapes health policy rather like the Human Rights Acts shapes legal judgements. I don’t deny that there is a responsibility of health professionals to promote health and well-being, as well as to diagnose and treat ill-health and disease. However, where, alongside this responsibility and the patient’s right to receive lifestyle advice, is the patient’s equally important right not to be lectured to?

Like all GPs, I regularly talk to patients about their lifestyle – where it is appropriate. The idea that GPs should promote good health has been enshrined in the very fabric of the GP consultation since at least the 1970’s. I am not afraid to confront quite forcefully when it is needed, and I know it can make a huge difference to a patient who is ready to change. I will always remember seeing a man in a hospital clinic many years ago who had recently had a stay in hospital with his first episode of angina. ‘Can you thank that young doctor who admitted me?’ he said. ‘She so frightened me about my smoking that I handed her my packet of cigarettes and haven’t touched one since!’  I was only too pleased with the result, and to pass on his thanks. What I decided not to tell him, however, was that rather than waste his cigarettes she had smoked every one!

However, there is a major difference between challenging a patient when they are ready to consider change, and lecturing, nagging and bullying patients when they are not. The latter is not only irritating and stressful for the patient, but also counter productive in terms of psychological theory – one of the basic premises of which is that if someone is not receptive to change then you should stop pushing (you can find out more about this by reading about Motivational Interviewing if you are interested). If I have not seen someone for a while then it may well be worth raising the issue of smoking even if they have come in for a quick chat about something else – maybe they are ready and I can strike while the iron is hot – but many of my patients I know better than that. We will have talked about smoking, or weight, or whatever, many times before and sometimes they just need to know they can have a break – permission to see me without being told off, without feeling guilty.

I don’t think this paper will change anything at the moment, but I worry about where the Government will go with it. Once they start to enshrine it in the NHS Constitution it is only a step away from red tape and performance targets – nurses spending yet more time away from the patient while they tick the box marked ‘Making Every Contact Count’, GPs being paid according to how often they raise lifestyle issues regardless whether the patient wants it, pharmacists being incentivised to talk about lifestyle rather than actually answering the patient’s queries – and patients being afraid to come near us all for fear of yet another lecture.