Smoking out ‘deniers’ and ‘dissidents’

[Originally published at Spiked on February 19 2009]


In a five-page journal article published online, Martin Dockrell, the policy and campaigns manager for the UK’s main anti-smoking campaign, Action on Smoking and Health (ASH), has launched an extraordinary attack on the journalist and broadcaster Michael Blastland (1). Calling him a ‘conspiracy theorist’ and a ‘dissident’, Dockrell explicitly compares Blastland to the ‘AIDS dissidents’ who disputed the link between HIV and AIDS.

Blastland’s crime was to criticise a study that claimed that the incidence of acute coronary syndrome (ACS) fell by 17 per cent after Scotland’s public smoking ban came into force in 2006. The study then applied a logical fallacy: since the reduction followed the ban, it must have been caused by the ban. Blastland covered the story for the BBC in November 2007, two months after the findings were reported by the international media following a presentation at a tobacco control conference.

Since the paper was, at the time, unpublished, Dockrell accuses Blastland of ‘reject[ing] the research before they had had the opportunity to look at it’. Strangely, Dockrell does not criticise those journalists who unquestioningly reported this unseen study with headlines such as ‘Scottish smoking ban brings big cut in heart attacks’ (2). Nor does he criticise the Scottish government for producing a press release to promote the findings. And he has nothing to say about the report author Jill Pell’s decision to announce the results of a study that had been neither peer-reviewed nor published.

Nor, for that matter, does he criticise his own boss at ASH - Deborah Arnott - for greeting the study with the words: ‘We knew from epidemiological statistics there was a risk from secondhand smoke to cardiovascular health, but not how much of a risk until now.’ (3) For Dockrell, blind faith is the only acceptable response to an unpublished study. Scepticism is not.

Blastland had good reason to debunk the study. Using official data from the Scottish National Health Service (NHS), he could see that the fall in heart attack admissions had been nowhere near 17 per cent: ‘These [data] show a fall in heart attacks for the year from March 2006 - not of 17 per cent, but less than half as much at about eight per cent. What’s more, taking out the recent trend, this is halved again. Heart attacks have been falling steadily for some years now.’

This was the essence of Blastland’s critique. Using official data, rather than the case group selected by Pell, it was plainly obvious that the fall in 2006-07 was an unexceptional extension of an existing downward trend. (For more on Blastland’s article, see Health fears go up in smoke, by Christopher Snowdon).

One of the most puzzling things about the Pell’s ‘StopIt’ study was that she chose to use a sample group when hospital admission data was freely available. Dockrell leaps to her defence, saying: ‘Pell makes no secret of the difference between the data from the StopIt study and the routine discharge data… Although Pell and colleagues had access to the AMI [acute myocardial infarction] discharge data, the StopIt study refers to ACS, a broader measure for heart attacks, verified by assay.’

This is true, but Dockrell fails to mention that Pell had access to the ACS discharge data, too. Everybody does - it is freely available on the Scottish NHS website - and it shows that admissions fell by 7.2 per cent in the first year after the smoking ban and rose by 7.8 per cent in the second year.

Brazenly ignoring the elephant in the room, Dockrell does not mention the rise in admissions in year two, instead pointing out that ‘raw discharge data’ from hospitals is ‘not peer-reviewed’ and suggests that it is not, therefore, reliable. This is not only a ridiculous assertion, it is also a slur on those who compile them. The NHS employs professional statisticians to compile and publish this data. There is no requirement at all for these figures to be peer-reviewed by a medical journal. They are official statistics, reviewed meticulously before being published.

It is hard to believe that Dockrell is seriously suggesting that Pell’s 20-month study of patients in a selection of hospitals trumps a decade of comprehensive data from the Scottish NHS, but that does seem to be the implication.

The news that rates of acute coronary syndrome are now higher in Scotland than they were before the smoking ban was enforced would have been enough to kill off the hypothesis in a less politicised area of research. The Scottish ‘miracle’ has ceased to be. It is no more. It has gone up to join the choir invisible. If Pell hadn’t nailed it to its perch, it would be pushing up the daisies. But instead of quietly backing away from this minor embarrassment, ASH has resolved to defend it at any cost. Left high and dry by the facts, they have resorted to name-calling.

Ad hominem attacks are often used against those who question any aspect of passive-smoking epidemiology. Activists frequently accuse critics of being employees or ‘allies’ of the tobacco industry. Such claims are usually untrue, and certainly are in the case of Michael Blastland. But he writes and broadcasts for the BBC - hardly a pro-tobacco organisation - and is the author of The Tiger That Isn’t, a book which looks at the misuse of statistics. He rarely discusses smoking at all except when, as here, it involves statistical sleight of hand.

Deprived of an opportunity to accuse critics such as Blastland of being in the pay of industry, Dockrell resorts to the slur of saying that: ‘Their position echoes the so-called “AIDS dissidents” who continued to contest that HIV was a causal agent in AIDS long after the scientific debate was over.’

This is a poor argument, particularly coming from a member of ASH. Anti-smoking activists like Dockrell are the first to complain when smokers’ rights groups accuse them of being ‘Nazis’ on the basis that the modern anti-smoking campaign has ‘echoes’ of Hitler’s own efforts to stamp out tobacco.

Comparing critics of these heart studies to AIDS deniers could hardly be more spurious. AIDS deniers, as Dockrell states, protested ‘long after the scientific debate was over’. Debate about studies that purport to show that smoking bans reduce heart attack admissions has barely begun. The first of them only appeared in 2003 and the majority of the other studies have been published in the past two years. Pell’s paper appeared barely six months ago. To compare this slender and recent body of epidemiological evidence to the vast body of scientific evidence about HIV is absurd.

By mentioning the AIDS ‘dissidents’, Dockrell is clearly attempting to persuade the reader that both bodies of evidence are of equal merit, and both sets of detractors are equally deranged. Worryingly, this fallacious argument comes hot on the heels of an article published in the European Journal of Public Health, titled ‘Denialism: what it is and how should scientists respond?’. The article, by the journal’s editor Martin McKee, groups together creationists, AIDS deniers and critics of the Pell study as being peas in the same pod (4).

McKee writes: ‘It took many decades for the conclusions of authoritative reports by the US surgeon general and the British Royal College of Physicians on the harmful effects of smoking to be accepted, while even now, despite clear evidence of rapid reductions in myocardial infarctions where bans have been implemented, there are some who deny that secondhand smoke is dangerous.’

The implication is clear: those who dispute studies such as Pell’s also deny that primary smoking is dangerous. Somewhat inevitably, McKee then introduces the most infamous and most repellent form of ‘denial’: Holocaust denial. ‘This phenomenon has led some to draw a historical parallel with the Holocaust, another area where the evidence is overwhelming, but where a few commentators have continued to sow doubt.’

This goes beyond the pale, but it serves as a reminder of why the word ‘denier’ is becoming so popular amongst those who would prefer to close down debate. It is quite deliberately chosen to bring to mind images of cranks, fraudsters and neo-Nazis. It is, perhaps, the ultimate insult and it is, of course, utterly fallacious.

The evidence for the Holocaust is documented in hours of film footage and is remembered by hundreds of thousands of eyewitnesses. Similarly, the link between HIV and AIDS has been proven by solid biological evidence. What McKee laughably calls the ‘clear evidence of rapid reductions in myocardial infarctions where bans have been implemented’ consists of nothing more than a handful of epidemiological studies of dubious value, created and funded by highly partisan bodies and individuals. Comparing this feeble selection of flawed studies to the thousands of studies conducted into primary smoking, let alone 60 years of evidence for the Holocaust, is obscene.

This kind of abuse ‘echoes’ (as Dockrell might say) the accusation - common in Stalinist Russia - that those who failed to accept the state’s ‘scientific Marxism’ (or the junk science of Lysenko) were either mentally ill or were ‘dissidents’ (Dockrell uses the word dissidents or dissidence seven times in his article). This prevailing view effectively ended scientific and political debate in the Soviet Union in the 1930s just as Dockrell and McKee would like to end the debate over the ‘heart miracles’ today. Both their articles push for a revival of the notion of scientific heresy, rebranded as denialism, something so devilish that it must not be allowed to be heard. It is hard to think of a concept that could be further removed from the scientific method.

Dockrell refers to the famous criteria of causation set out by the noted epidemiologist Austin Bradford Hill - who produced the first, definitive research on smoking and lung cancer in the UK - and claims that the Pell study would pass Hill’s test of strength and consistency. Aside from the fact that the rise in heart attacks in year two of the smoking ban shows this to be sheer nonsense, both he and McKee would do well to remember that neither Hill nor his colleague Richard Doll ever resorted to character assassination when their early studies were contested by other scientists. They might also learn from the example of Albert Einstein, who invited Arthur Eddington to put his ideas to the most rigorous of tests. Or do they believe the findings of Dr Pell to be more robust than the theory of relativity?

Scientific debate should not be reduced to ad hominem attacks. Good scientists are happy to have their theories scrutinised, even when they believe their opponents to be utterly misguided. Good scientists do not announce their findings to the press and then refuse to answer questions. Good scientists do not refuse to release their raw data. Good scientists do not claim that a scientific debate is over before it has been allowed to begin. Above all, good scientists do not slander their critics with barely concealed accusations of madness, corruption or worse.

It is time for the scientific community to speak out about the erosion of scientific discourse and reject the ugly concept of ‘denialism’, censorship and all the twisted reasoning inherent in the rottweiler-style attacks of Dockrell and McKee.



(1) ‘Eye and heart at mortal war: coronaries and controversy in a smoke-free Scotland’, Martin Dockrell, Expert Review of Pharmacoeconomics & Outcomes Research, February 2009

(2) Smoking ban brings big cut in heart attacks in Scotland, study finds, Guardian, 17 September 2007

(3) Heart attacks drop by 17 per cent after smoking is banned, Daily Mail, 17 September 2007

(4) ‘Denialism: what is it and how should scientists respond?’, European Journal of Public Health, 2009, 19 (1): pp.2-4