Wednesday, 29 October 2014

The risks of drinking

There's a nice illustration of the gulf between 'public health' and reality in BMC Medicine this month in an essay entitled:

Why does society accept a higher risk for alcohol than for other voluntary or involuntary risks?

When the authors (some Canadian folk who credit temperance stalwarts Ian Gilmore and Tim Stockwell for providing 'helpful comments') say 'society' they really mean 'the government', but their question becomes much easier to answer if it is framed properly as:

Why do people accept a higher risk for alcohol than for other voluntary or involuntary risks?

The answer, quite obviously, is that drinking is highly enjoyable, the benefits are large and the risks are small to non-existent for moderate drinkers and tolerable for heavier drinkers.

Remarkably, this answer barely occurs to the authors. Instead they point the finger at things like alcohol's "cultural acceptance among elites in most western societies". They suggest that "the risks of alcohol may not be fully understood by the general public" and that "the addictive properties of alcohol cloud the consumers’ ability to assess information and make a free choice" And, inevitably, they blame "the strong political influence of global alcohol producers".

The methodology employed in this paper is rather odd. The whole article seems designed to revive the old temperance belief that there is no such thing as a safe drink and it hinges on this graph, which purports to show the absolute risk of dying as a result of alcohol consumption before the age of 70.

This graph bears no resemblance to the actual relationship between alcohol and all-cause mortality which, as regular readers will know, is a J-curve. (Note that one drink is about 15 grammes of alcohol.)

Their assertion that drinking just over one drink a day gives you a one in 100 chance of dying from an alcohol-related disease before the age of 70 flies in the face of so much evidence that there is little point in continuing. Nevertheless, this is how they proceed:

How do these risks compare to other acceptable risks in society? Many of the fully involuntary risks, such as unsafe water provided to a household, have risk thresholds set at one in one million. Indeed, the one in one million has become something of a gold standard of acceptable risk for involuntary exposure and has been used in different areas such as water safety in Australia and the US, or for increases of exposure to carcinogens in air, sediment or soil. 

Fine. It makes sense to be highly risk averse when it comes to water pollution or carcinogen exposure so long as there are low-cost ways to eliminate risk and there are no benefits lost by doing so. Nobody wants to drink unclean water. Lots of people want to drink alcohol.

Involuntary risks are associated with activities, conditions or events to which individuals might be exposed without their consent. Examples of involuntary risks include the risks of natural disasters (earthquakes, floods, and so on), or technology-related risks such as bad air quality or contaminated water.  

People who live on fault-lines and flood plains are exposed to earthquakes and flood with their consent. Millions of people live in California with the sure knowledge that the Big One will come sooner or later. The benefits they enjoy from living in California (God knows what they are) outweigh the risk of having their home razed to the ground and the possibility of being killed.

It should be noted that other standards have been used, and sometimes we see ranges, such as one in a million to one in 100,000. Starr found that the public seems to be willing to accept voluntary risks roughly 1,000 times greater than involuntary risks. By this standard, an acceptable risk for voluntary risks experienced by the drinkers themselves is one in 1,000 deaths for the pattern of behaviour over a lifetime. 

Do you know what else Starr said in his classic 1969 essay? He said this:

In the case of "voluntary" activities, the individual uses his own value system to evaluate his experiences. Although his eventual trade-off may not be consciously or analytically determined, or based upon objective knowledge, it nevertheless is likely to represent, for that individual, a crude optimization appropriate to his value system...
"Involuntary" activities differ in that the criteria and options are determined not by the individuals affected but by a controlling body.  

He was right. Involuntary risks that affect whole populations may require action by 'a controlling body'. Voluntary risks, like drinking, don't.

They continue:

If we accept the stated acceptable risk of one in 1,000 deaths, drinking 20 g pure alcohol per day (equivalent to 1.5 to 2.5 standard drinks dependent on the national standard drink: 8 g pure alcohol per drink in the UK, between 10 and 14 g in other European countries) exceeds this threshold ... drinking 20 g pure alcohol per day seems to exceed a threshold of one in 100 for death on a lifetime basis

Firstly, drinking 20g of alcohol per day does not exceed that 'threshold'.

Secondly, drinking 20g of alcohol every day for decades is not a single action. It is many thousands of individual actions over a course of a lifetime.

Thirdly, insofar as the one in a thousand shot is a meaningful threshold, it applies to voluntary behaviour and is therefore a matter for individuals, not 'a controlling body'.

To put this in perspective, the average level of daily consumption in EU countries in 2012 was about 31 g pure alcohol per day among drinkers, entailing a mortality risk beyond this threshold. This level of drinking has led to a situation where every seventh death in men and every 13th death in women before age 65 in the EU is caused by alcohol. Clearly, this level of risk is not acceptable by usual standards. 

This is willfully misleading. Aside from the fact that the statistics are questionable, the reference to average consumption of 31g of alcohol clearly aims to reinforce the false impression that this is a dangerous amount to be drinking. In fact, alcohol-related deaths before the age of 65 are dominated by liver cirrhosis—which requires a much, much larger alcohol intake than that—and various causes such as suicide, drink-driving and violence which tend to be the result of acute intoxication, not persistent but moderate consumption.
Only at the very end of the article do we get this brief, bewildered acknowledgement:

Or may the actual or perceived pleasurable effects of alcohol consumption (that is, benefits) be so high that the informed choice of a mortality risk in the 1:100 range is seen as “reasonable risk”, so that there is no pressure from the public for government action, and governments are dissuaded from effective alcohol policies such as raising taxes?

That's exactly what it is. Well done. Even if drinking at that level led to a 1 in 100 risk of premature death rather than - as is actually the case - a reduction in the risk of premature death, it would be entirely reasonable for people to do it if they enjoy it. See also driving a motorbike, going skiing, climbing mountains, eating cream buns or any of the other comparable activities that are brought into these debates.

If, however, someone doesn't feel that the benefits are worth it—either because they don't really enjoy drinking or because they are particularly neurotic about their health—then they are free to abstain. What they don't do, unless they work in public health, is demand "government action" and higher taxes for people who don't share their preferences.

Tuesday, 28 October 2014

Dead rock stars

Chuck Berry: fading away, not burning out

As covered in the Daily Mail and elsewhere, a study has come out of the University of Sydney which concludes that rock stars tend to die younger than the general population.

Well, duh, you might say. And rightly so. A cursory knowledge of music history tells us that rock stars are more likely to die from drug overdoses, plane crashes, suicide etc. and this is confirmed in the study.

But I was startled to find that the author has also attempted to compare rock stars' longevity to the average.

Longevity was determined by calculating the average age of death for each musician by sex and decade of death. These averages were then compared with population averages by sex and decade for the US population (per 100,000).

And she has come up with this graph...

You see the problem here, I expect. Rock stars didn't exist until the 1950s and since many of them are still alive, we don't know what their average age of death is. It wouldn't be at all surprising if they die earlier on average, but the graph above tells us very little about whether this is so. When Chuck Berry (aged 88), Jerry Lee Lewis (aged 79) and Little Richard (aged 81) pop their clogs, the average is going to go up, especially if they keep breathing for another twenty years.

And, who knows? They might. Perhaps the higher risk when young is counter-balanced by the boost to longevity of having lots of money and the best healthcare in old age?

Be that as it may, you clearly can't work out the average lifespan of a rock star until at least the first generation of rock stars are dead.

I can't find the study, so I apologise to the author if I am misrepresenting her work, but somebody raised this question with her in the comments and her reply was not very convincing.

There is a small amount of survivor bias at work here, ie. the rock stars have to live to be in their twenties (generally) before they become rock stars. That probably isn't a big issue when so few people die before the age of 20. The real problem here is a sort of reverse survivor bias, sort of like immortal time bias, but not quite either of those.

So, my question is: does this fallacy have a name?

Monday, 27 October 2014

Health über alles

During the closing overs of the farcical WHO conference in Moscow (COP6) delegates agreed to something called the Moscow Declaration. In keeping with the fog of secrecy that surrounded this covert meeting of unelected tax-spongers, the text of this declaration has not been released, but I've seen a draft. It contains some delusional prohibitionism (eg. "The desired goal of tobacco control measures at the international and national levels is complete victory over tobacco"), but there is also this striking assertion:

The right to enjoyment of the highest attainable standard of health, guaranteed by international law and national legislation of the vast majority of States, takes precedence over any laws related to tobacco use. There is no fundamental right to tobacco use.

Leave aside the question of whether it is really a fundamental right to have ‘the highest attainable standard of health’ in the sense that such a right could ever be asserted in court. Leave aside the fact that in a free society you don’t need a specific right to smoke; if it hasn’t been explicitly forbidden you have the right to do so. Leave aside the fact that this 'right' can, it seems, not be revoked by smokers even though it's their body; the WHO wants to enforce it without their consent. And leave aside the fact that the WHO has no democratic legitimacy and that this quote comes from a meeting held in Russia from which the public and the media were banned.

Instead, look at what is being said here, namely that the supposed right to perfect health takes precedence over democratically decided laws and other written or unwritten rights; that the pursuit of health is the highest priority, trumping all other concerns.

This is obviously untrue. Obvious, because not a single person lives their life as if longevity was the only, or even main, goal. If people wanted to attain the highest standard of health at the expense for all else, they would behave as if they did. They would sacrifice earthly pleasures and there would be no need for a public health movement. The very fact that a public health movement exists is proof that people don’t want it. What is not true for the individual cannot be true for the collective.

Faced with the awkward fact that people are free to live a life of purity but prefer to make trade-offs between health and other goals, the 'public health' lobby has come up with a range of ad hoc explanations which amount to a revival of the concept of false consciousness: that people buy products because they’re too cheap, or advertised too much, or too readily available.

These arguments cannot be supported by empirical evidence, personal experience or logical deduction. In reality, people offset costs against benefits, risk against pleasure, quality of life for longevity. The fatal conceit of the public health movement is it portrays one important, but narrow, goal as if it were the only thing that matters.

Carl Philips explained this very nicely in a blog post that should be read in full:

I recall a conversation with a fellow economics-trained assistant professor of public health. I forget the specific trigger for our observation, but it came after a meeting of faculty, when we both realized that we were surrounded by idiots. The issue was public-health-based policy recommendations and their absurd implicit objective function. Our observation was that in economics we often lean on the convenient myth that people’s goal is to maximize their lifecycle welfare, and that social policies should be based on that. It is easy to demonstrate that this is an oversimplification of behavior, and to argue from an ethical standpoint that there should be some departures from this in policy. But at least our simplified fiction is basically sound, both practically and ethically: Trying to maximize their welfare is roughly what people do, and there is an obviously defensible case to be made that trying to assist with such maximization is an important ethical goal — if not the ethical goal — of public policy.

We observed how sharply this contrasted with the implicit objective function in almost every public health policy discussion, which is basically “maximize longevity at any expense, and everything else be damned.” The economists who study medical care at least interject into this the caveat that some financial expenditures are too much to pay for the tiny bit of extra longevity they provide. But to the public health people, all other costs and benefits are trumped by the one objective. Economists’ objective function, we agreed, was not quite right, but at least it was generally defensible. The public health view, on the other hand, was utterly absurd. No one wants to live their life according to such an objective. Not even close. And therefore there is no possible way to justify it as an ethical goal for public policy.

The core belief behind 'public health' movement, as it is today, is so ridiculous that it can never be said out loud. Even the Moscow Declaration only hints at it.

As Carl points out in his post, the public healthists are not always consistent with their 'health über alles' mentality. They do not recommend that women have as many children as they can from a young age to reduce their risk of breast cancer, despite childlessness being a risk factor. They will not tell teetotallers to start drinking, despite teetotallism being a risk factor for heart disease. With some exceptions, they won’t support the use of e-cigarettes. But this only demonstrates how many moral zealots work in public health industry.

The public health industry is not a single entity. It is partly made up of those who have a connection with the medical establishment but who have taken the whole thing too far by ignoring trade-offs between longevity and other goals. And it is partly made up of moral entrepreneurs, puritans, and other single-issue cranks who, in the absence of a 'public health' movement to latch on to, would be campaigning under a placard outside some town hall or other.

It is hardly surprising that old school fanatics have been drawn to a movement that has more credibility and—crucially—more money than the impecunious moral reform groups of earlier eras. Once the public health lobby decided that a single objective trumps all other concerns, they became fanatics by definition and other fanatics were drawn in like moths to a headlight.

Friday, 24 October 2014

The great British booze rip off

From the Morning Advertiser:

UK consumers currently pay about 40% of the entire level of alcohol duty across the whole European Union.

This is a striking claim. I had heard that the British pay 40 per cent of all the beer tax in the EU, but I didn't realise that the same was true of all other alcoholic drinks.

Nevertheless, a check of the numbers in this EU document shows that it is true. The figures break down like this:


EU total: €14.5 billion
UK total: €3.7 billion
UK percentage: 25%


EU total: €6 billion
UK total: €4 billion
UK percentage: 67%


EU total: €10
UK total: €4 billion
UK percentage: 40%

Sparkling wine

EU total: €1 billion
UK total: €460 million
UK percentage: 43%

Intermediate ('alcopops')

EU total: €700 million
UK total: €406 million
UK percentage: 58%

All alcohol

EU total: €31.2 billion
UK total: €12.5 billion
UK percentage: 40%

This is a rip off of British drinkers on an epic scale. The UK—which drinks less than the EU average—has 12 per cent of the EU population but pays 40 per cent of alcohol taxes. Pound for pound, we are paying more than three times as much alcohol duty than the EU average.

The exploitation of wine drinkers is particularly ruthless (most EU countries don't levy alcohol duty on wine at all), but every type of drink is subject to exceptionally high rates of tax. No wonder the European Commission thinks the British government can afford to give it another £1.7 billion.

Couch potatoes

From the Telegraph:

Couch potato lifestyles could kill the welfare state, landmark report warns

Couch potato lifestyles have left the UK with one of the lowest levels of activity in the western world, and without change, the welfare state could collapse, health officials have warned.

If the welfare state is so fragile that it can be brought down by people sitting about, perhaps we need a better system?

The welfare state won't be brought down under the weight of couch potatoes, however. This is just the latest scare story about obesity/smoking/drinking etc. bringing the NHS to "the brink of collapse". As I'm sure you know by now, obese people have lower heathcare costs than non-obese people.

At least Public Health England—for it is they—are talking about physical inactivity.

Officials warned that the UK population is now 20 per cent less active than it was in the 1960s...
The report by Public Health England says the typical lifestyle in Britain, with long hours spent in desk jobs, high levels of car travel and evenings spent watching TV or playing computer games is endangering the health of most of its population.
It warns: “Social, cultural and economic trends have removed physical activity from daily life. Fewer of us have manual jobs. Technology dominates at home and work, the two places where we spend most of our time. It encourages us to sit for long periods – watching TV, at the computer, playing games or using mobile phones and tablets. Over-reliance on cars and other motorised transport is also a factor.”

Indeed. I have been saying this recently on this blog and in an IEA report. If Public Health England conceded that calorie consumption has also been falling, we might get closer to understanding the real cause of the obesity 'epidemic'.

Michael Blastland gave a superb talk at the Battle of Ideas on Sunday in which he questioned why 'public health' folk tend to focus on diet, but not on exercise. He concluded that it is because there is no industry to attack and no legislation to campaign for. This, I think, is absolutely true. The public health lobby are one club golfers. If they can't blame industry for all the troubles of the world, they don't know what to do.

On a slightly related note, I am reminded of an anecdote in the great Petr Skrabanek's The Death of Humane Medicine which illustrates the yearning of epidemiologists to explain every premature death by reference to lifestyle.

When death strikes 'before its time', the victim's lifestyle becomes the subject of scrutiny. Death does not just happen. Something or somebody must be blamed. Obituarists casually search for snippets from the dead person's way of life which would 'explain' the timing and the mode of death.
When a 33-year-old friend of an epidemiologist suddenly died of a heart attack, without having any 'risk factors', the epidemiologist was greatly puzzled and so were his medical colleagues. 'The heart attack should not have occurred in this patient', was the verdict of experts. But it did. It was not fair. Was he a secret smoker? Had he used too much salt at home, even though he appeared to be shunning it in the hospital canteen? Then, finally, one doctor solved the mystery - the young man was a 'couch potato'.

All of Skrabanek's excellent books can be downloaded free here.

Thursday, 23 October 2014

Good cop/bad cop - how the BBC frames the debate on sugar

The BBC wants to know when if you've stopped beating your wife.

Last night the BBC broadcast Trust Me, I'm a Doctor. It featured a segment about sugar that was a nice example of how the media can narrow the terms of a debate while pretending to be neutral.

It started by showing some of the hysterical claims about sugar being 'the new tobacco' before declaring that it would be presenting the views of two scientists who held wildly differing opinions about the subject.

"To find out more, I've invited a couple of leading experts whose research has led to contradictory headlines..."

One of these experts was Simon Capewell of the anti-sugar pressure group Action on Sugar.

The other was Mike Rayner from the, er, anti-sugar pressure group Action on Sugar.

Only Capewell (bad cop) was introduced as being from Action on Sugar and it is simply not true that their research "has led to contradictory headlines". Both of them think that sugar is the leading cause of obesity, both of them think that the government should intervene in people's diets and both of them want sugar taxes. Rayner's research focuses on what a jolly good thing it would be if we taxed sugar and fizzy drinks. Capewell entirely agrees.

The main differences between the two is that Rayner (good cop) believes he is doing the Lord's work and he would like to broaden food taxation to go beyond sugar to deal with the whole diet:

"I don't care whether it's hot or cold, whether you got it from a takeaway or a shop - I'd like us to tax all unhealthy foods from butter to biscuits."

You can watch extended interviews of Capewell and Rayner by clicking on the links. Rayner certainly comes across as the saner and more thoughtful of the pair—and so he is—but this is because he rejects the garbage about sugar being addictive and/or toxic (which Capewell virtually admits he has to spout in order to get the attention of politicians).

Only in the fruity world of 'public health' can this be considered a meaningful difference. From Rayner's perspective, it is more reasonable to tax calories as calories rather than demonise sugar per se, but that is still a patently extreme point of view. And yet this guy is being wheeled out as the voice of reason!

I won't fisk Capewell's interview, although I am tempted. I hope that anyone who watches it will spot his duplicity and evasiveness when answering questions, as well as the eagerness of the presenter to help him out (to a laughable degree when the topic turns to addiction). Rayner got a slightly rougher ride, but there was no acknowledgement of the role of physical inactivity in causing obesity, nor was there any recognition of the fact that per capita sugar consumption is the same today as it was a hundred years ago. Both sides agree that sugar is the villain and the government needs to act, preferably with taxes.

By only showing us the devil and the deep blue sea, the BBC managed to make Rayner look like the good cop and Capewell the bad cop, but it was like a debate between a Marxist-Leninist and a Maoist, or a Hayekian against a Friedmanite. The shades of disagreement might seem significant to those who have already picked a side, but they are meaningless for those who want to see the bigger picture.

The effect—and, I assume, the intention—was to shift the debate from 'what's going on?' to 'what shall the government do?'

Monday, 20 October 2014

Heart miracles: Is the truth emerging?

If there is one pseudo-scientific claim that illustrates the credulity of the media and the duplicity of the public health movement better than any other, it is the idea that smoking bans lead to dramatic reductions in heart attack incidence.

It is now ten years since the British Medical Journal published Stanton Glantz's notorious 'Helena Miracle' study which claimed that the heart attack rate fell by 40 per cent after a small town in Montana banned smoking in pubs and restaurants. Numerous copycat studies followed, typically involving thinly populated towns and regions which, because of the small number of heart attacks that take place each month, are given to large fluctuations in hospital admissions.

From the outset, the most plausible explanation for the heart miracle phenomenon was that activist-researchers were scouring hospital records for unusual declines in heart attack admissions that roughly coincided with 'smokefree' laws. With so many smoking bans being enacted, it was inevitable that they would coincide with a blip in admissions now and again.

But when whole nations bring in smoking bans, the rate of decline has typically been zero or in the low single digits, ie. in line with the long term trend. (The most notable exception was a study of Scotland which claimed a 17% decline—a finding that is totally inconsistent with official NHS data.)

Having written about this for the five years, I was pleased to see some sanity rear its head in the American Journal of Medicine in January. A study by Basel et al.—which I have only just become aware of it thanks to Klaus in Denmark—looks at rates of acute myocardial infarction (heart attacks) in Colorado after a statewide smoking ban went into effect in 2006. This is of particular interest since two widely touted heart miracle studies have involved small pockets of Colorado. A 2006 study of Pueblo, Colorado claimed that there was a 27% decline in heart attacks when it went 'smokefree' in 2003 and a 2006 study of Greeley, a small town in Colorado, also claimed a 27% decline.

The researchers looked at the data for the whole of Colorado before and after its strict statewide smoking ban came into force. They looked first at total admissions for acute myocardial infarction and then they excluded the eleven towns and counties that already had smoking bans in place. In both instances, they found no effect from the ban.

We did not observe a significant decrease in acute myocardial infarction hospitalization rates in Colorado after enactment of a comprehensive statewide smoking ordinance. Even after removal of geographic regions where preexisting smoking ordinances were under enforcement, no statistically significant reduction in acute myocardial infarction hospitalizations was detectable. This contrasts with a number of prior studies, including local smoking ordinance studies in Pueblo and Greeley, Colorado, and adds to a growing literature that the cardioprotective effect of smoking bans may be less than initially suggested.

This finding is important and telling, but the study is also worth reading for its discussion of the existing literature. It is clear that heart miracles are confined to small, obscure towns in a way that can only be described as suspicious. (I have inserted hyperlinks to each study mentioned below.)

Overall, a review of published research shows that acute myocardial infarction RR reduction appears inversely related to sample size. For example, small studies in Bowling Green, Ohio, and Helena, Montana, found dramatic RR reductions (39% and 40%, respectively) but also had few acute myocardial infarction counts (58 acute myocardial infarctions in Bowling Green, 64 acute myocardial infarctions in Helena) and relatively small study populations (30,052 and 68,140, respectively). Studies in Greeley and Pueblo, Colorado, and Graubünden, Switzerland, found less dramatic RR reductions (27%, 27%, and 22%, respectively), corresponding to somewhat larger study populations (∼86,000, 147,751, and 188,000, respectively).

As the authors note, these large declines in small communities (which are not just implausible, but mathematically impossible), contrast sharply with evidence from large communities and whole nations. national study used Medicare Provider Analysis and Review files and national death records; a nonsignificant reduction in acute myocardial infarction-related (RR, −4.1; 95% CI, −9.4 to 1.3) and all-cause (RR, −0.7, 95% CI, −2 to 0.6) mortality was observed 1 year after smoking ordinance enactment. In this study, researchers evaluated all possible pairs of ordinance and nonordinance hospitals and recorded the change in acute myocardial infarction incidence post-ordinance. They found that RR reductions of 10% or greater were common, but that RR increases of 10% or greater were equally as common; taken in aggregate, the mean was near zero.

Another study examined 74 cities geographically distributed across the United States that were affected by smoke-free legislation. Individual cities showed wide variation in acute myocardial infarction incidence after ordinance enactment, with risk ratios ranging from −36% to +54%; however, the mean risk ratio for the 74 cities was 0.97 (95% CI, 0.96-1.02).

... A study performed in Christchurch, New Zealand after a countrywide smoke-free ordinance, found a 0% RR reduction in acute myocardial infarction with an approximate population size of 350,000. Countrywide studies with larger population bases provide concordant findings. In England, a 2.4% RR reduction was observed (population of 50 million). In Italy, a 4% RR reduction was observed (population of 58 million). In France, a 0% RR reduction was observed (population of 63 million). Finally, in a study examining the US Medicare population in states with a smoke-free ordinance versus those without, a 0% RR reduction was demonstrated (population of 30 million).

In the case of the English study, the heart attack rate fell at exactly the same rate after the smoking ban as it had been doing before the smoking ban. After dressing this up with some superficial computer modelling, Anna Gilmore—for it was her—relied on nothing more than a post hoc ergo propter hoc assumption. A similar claim, though never published, was made about Wales.

The authors attribute much of the heart miracle phenomenon to publication bias. That is likely to be a part of it, although I think that researcher bias and selection bias played more of a part.

These analyses support the hypothesis that small study populations may be more likely to find dramatic changes in acute myocardial infarction incidence, whereas increasing the study sample size attenuates the magnitude of the reduction. Also, review of the studies in aggregate reveals data asymmetry that suggests the potential for publication bias or heterogeneity not entirely explained by a random-effects meta-analysis. The presence of publication bias may explain why small sample size studies have tended to report large decreases in acute myocardial infarction incidence, whereas relatively few small sample studies have shown no effect.

The whole heart miracle scam has, in my view, been built on two simple tricks:

Firstly, dredging the data for any town that saw a large decline (in percentage terms) in heart attacks at around the time of a smoking ban. Nobody decided to do a study of Helena, Montana or Bowling Green, Ohio before the bans took place. The decision to focus on such obscure places came about only once it was clear that they were anomalous (not unlike Derren Brown's horse-racing trick). They were then presented to the media with the implication that they had been randomly selected.

Secondly, although less frequent, studies of larger populations have portrayed rather small declines in the heart attack rate as being the result of a smoking ban, without acknowledging that that there had been a secular decline of the same magnitude long before the ban was enacted. As the authors of the above study note, the secular decline is simply ignored in such cases.

That's really all there is to it. The 'public health' lobby has been selling this lemon to the public for ten years while describing sceptics, such as Michael Blastland (the creator of BBC's excellent More or Less series), as 'denialists' and 'dissidents'. The American Journal of Medicine study won't be enough to set the record straight in the public's mind—it received no media coverage, naturally—but it is further ammunition for those who do not believe in the 'noble lie'.