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Smoking ban health miracles

By Guest
April 15th, 2013 at 10:00 am | 7 Comments | Posted in health, pseudo science

Earlier this year a paper was published in a peer reviewed journal that was so contrived and so flawed that I had hoped it would convince any doubters that the evidence for miraculous immediate health effects from smoking bans is entirely the figment of activist’s febrile imaginations. Sadly, it appears that I was wrong and that true believers including David Cameron still cling to the notion that smoking bans “have had a pretty dramatic health effect”.  This delusion is shared by Anna Soubry who unforgivably and untruthfully claimed reductions in heart attacks and childhood asthma admissions as a result of the English smoking ban in evidence that she gave to the House of Lords (page 11).  The fact that she was standing next to the less than impartial Andrew Black at the time is no excuse as only someone without interest in truth or reality would take anything Black says at face value.

The “growing body of peer reviewed evidence” used to justify these counter-intuitive claims is an indictment of public health industry ethics and medical journal standards. This recent contribution claiming a 12% reduction is asthma admissions as a result of the smoking ban originates from Imperial College London which is cause for further concern because Imperial is a top UK research establishment and as such charges young people a small fortune to be educated by what one would hope are top academics.

The culprits behind this affront to science are Stanton Glantz and Christopher Millett. In case anyone is labouring under the illusion that these two are objective scientists, Glantz is a well-known anti-tobacco activist who together with Millett holds extreme views on smoking in movies. Glantz was recently mentioned in the US congress in relation to a $680,000 grant that he used to make the bizarre claim that the Tea Party was created 25 years ago by big tobacco. It is extraordinary that we ban tobacco company funded research on the basis of scientific objectivity but, by a widely accepted double standard, treat the output of blatantly biased activist obsessives as “scientific evidence” fit for Prime Ministers.

This paper is yet another example of torturing numbers to fit a theory. The authors produce a lot of complex statistical waffle to obscure the deception but their essentially simplistic claim can be illustrated using annual data for childhood asthma admissions from the same NHS source they use. In the figure below the blue bars are years pre-ban and the orange ones the year of the ban and one year later. The solid red line is a simple linear fit to the pre-ban data.

asthma 2002 2009

The claim that the ban reduced asthma admissions depends on showing that admissions rates were increasing pre-ban and that after the ban admissions were lower than predicted had that trend continued along the path illustrated by the dashed red line.  Millett uses the period 2002-2007 to model the “rising trend” in admissions but the NHS data goes back further and if we use all the available data the “trend” changes somewhat.

asthma 1998 2009

Cherry picking time periods is a common deception practiced by the public health industry together with taking advantage of coincidental variations in data series that happen to fit a theory or policy.

Those desperate to believe might argue that I am being too simplistic in that the “experts” took a more sophisticated approach and used monthly data. A 12% fall in admissions should not need sophisticated techniques to be apparent but it is true that 2007-08, the year of the ban, saw a big fall in admissions compared to the previous year. However, a look at NHS data for monthly admissions covering three years around the ban serves only to illustrate how the second element of the trick works.  asthma 2005 2008

If I asked a group of seven year olds which of the lines on the chart above was the odd one out, I would expect the majority to say the orange one. The orange line represents monthly admissions for the year before the ban. We can align the data on the month of July which was when the ban came in but it makes little difference. Admissions were low in the year the ban came into force but not unusually so. Both the alleged upward trend before the ban and the apparent fall in the year it was enacted work for the activists only because peak season admissions were unusually high in the year before the ban. That stroke of fortune combined with the cherry picked time frame form the basis of the deception.

This peer reviewed paper appears to be nothing more than a cheap trick, an abuse of academic freedom for political purposes. The authors admit to some of its flaws but this did not prevent them from issuing a carefully worded press release that inevitably led to a misleading claim being widely broadcast by a gullible and uncritical media. It even made BBC TV news! This is not an isolated incident. It forms part of a body of highly publicised but fundamentally flawed “research” that has led some politicians and at least one national leader to erroneously believe in unlikely health miracles associated with interventions such as smoking bans. This might well influence opinions when reviewing existing or considering additional interventions, which one can argue is the main purpose behind such publications and their attendant publicity.

Of course, those politicians obsessed with public health are never slow to accept even the most unconvincing “evidence” if it suits their prejudices. Despite widespread incredulity over the facile “evidence” underpinning the implausible notion that smoking bans produce big falls in heart attacks, Sarah Wollaston of minimum alcohol pricing fame has claimed that the UK smoking ban:

“…was a very good example of evidence-based policy. If you look at what has happened in terms of deaths of cardiac disease, it has been staggering. There’s been a huge drop … It surprised even the health experts.”

Wollaston exhibits blind faith in “evidence” that is of no better standard than the article reviewed here. Her need to believe does not make it true, or a good basis for policy.

I have contacted Pediatrics and asked how something so obviously contrived as the Millett paper could survive peer review. I was informed that it was reviewed by people who are “experts in their field”.  I wasn’t told what field, but expertise in either mathematics or ethics was apparently not considered necessary in this case. There are reasons why political stunts like this usually appear in medical journals rather than elsewhere in the literature and it is remarkable just how low some set the peer review bar. Peer review is supposed to be a minimum requirement able to identify fundamental methodological errors or false claims. Every time an article such as this is published in a “peer reviewed” journal, respect for this gold standard and science in general declines a little bit further. The collective damage is becoming significant and the implications extend way beyond smoking.

I have also contacted Imperial College press office but they have declined to comment on why they inflicted this press release on the general public. From direct experience I know that Imperial College employs many excellent lecturers and research scientists but based on this output I think that we should question what exactly young people are being taught for £9,000 a year and who is doing the teaching. Honesty, integrity and academic excellence are qualities that I would expect to see in those who benefit from the fees young people are now being asked to pay. I appear to be in a minority.

By Chris Oakley. Chris’ previous posts on Liberal Vision include: Minimum pricing – policy based evidenceAlcohol is Old News – Minimum Pricing for Digestives is the “Next Logical Step” , Soviet Style Alcohol Suppression Campaign Called for By Public Health Activists , Alcohol Taxation: The truth, the whole truth and nothing but the truth Lies, damn lies, statistics &… , The Department of Health is Watching You! , New bounty on smokers helps GPs balance their books.

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Minimum pricing – policy based evidence

By Guest
November 28th, 2012 at 9:42 pm | No Comments | Posted in BBC, health, pseudo science

Based on the output of the English media, one could be forgiven for not having noticed that Scottish ministers appear to have shelved minimum alcohol pricing ostensibly due to legal challenges. It will be unfortunate if minimum pricing is shelved solely on the basis of illegality because the lessons to be learned from the attempts to justify it via policy based evidence will then once again go unheeded.

We hear much talk of evidence based public health policy these days but what we actually get is “evidence” concocted to suit policy. The public health industry seems utterly incapable of delivering honest, objective, scientific evidence and the media contributes to the problem through lazy uncritical reporting combined with establishment bias. This was typified by the BBCs response to being caught out making wild claims about the number of lives minimum pricing would “save” amongst pensioners.  Rather than investigate the obviously questionable reliability of its source, the BBC simply accepted a lower but no more credible number.

The BBCs source was The University of Sheffield, which has now received involuntary taxpayer funding from two governments and a public broadcaster. On each occasion the motive has been the gathering of policy based evidence and it appears that neither the politicians nor the media appear to care how dubious the quality of that evidence is provided that it suits their purpose.

Petr Skrabanek in his 1994 work The Death of Humane Medicine cited Nobel laureate Irving Langmuir from 1953 when making a case against the “science” that underpins public health. He wrote that it “accepts evidence not according to its quality but according to its conformity with a foregone conclusion”. It seems that his wise observations have been ignored because the ersatz science that provides the “evidence” for policy interventions is nowadays more prevalent than ever. The University of Sheffield study provides a classic  example of this anti-science in which every supportive scrap of data, however poor in quality  is treated as “conclusive” or adding to a “growing body of evidence” and every contradictory piece as “flawed”, “controversial” or “in need of further research”.  Evidence at odds with the authors’ predetermined conclusions is often simply ignored. Take for example evidence statement 13:

“There is consistent evidence to suggest that alcohol consumption is associated with substantially increased risks of all-cause mortality even in people drinking lower than recommended limits, and especially among younger people. High levels of alcohol consumption have detrimental effects. The evidence is more equivocal, however, where it relates to establishing cut-off points for lower risk versus harmful levels of consumption. There is an ongoing controversy as to whether or not there are beneficial (cardio-protective) effects at low levels of alcohol consumption.”

This statement is an extremely misleading interpretation of the available evidence. There is no excuse for this form of words appearing in a document paid for by public funds and intended to guide politicians who are not versed in the subtleties of public health disingenuity. Hiding behind theoretical and contestable risk factors, the authors peddle the scientifically improbable but politically powerful concept of “no safe level” whilst ignoring a large body of evidence showing teetotallers to have lower life expectancy than moderate drinkers.  I could write extensively about the “controversy” they refer to but Christopher Snowdon already covered it in some detail.

Unfortunately this is not an isolated example in a production that goes to extraordinary lengths to provide policy based evidence.  The other “evidence” statements display a similar lack of objectivity and, despite using the Household Survey data provided by the ONS as a basis for much of their modelling, the authors ignore it when considering consumption at the population level.  They open their section on areas for possible future research (and of course more taxpayer funding) with the typically convoluted sentence:

Given the trends in consumption over the past ten years it is unlikely that a ‘do nothing’ policy would result in no change to the consumption of alcohol in the population.

It is hard to tell, but I think that they are trying to say that consumption is trending up so government MUST act. This is a remarkably inept statement to make in the middle of a trend that, according to the ONS has seen household consumption decline by 20% in a decade without any significant government intervention.

I find it hard to understand why politicians continue to pay homage to what Skrabanek described as healthism despite the huge flaws in the “evidence” that underpins it being repeatedly exposed. Perhaps Skrabanek gives some insight into the reasons when he writes:

Politicians find the facile rhetoric of healthism rewarding. It increases their popularity at no cost, and it enhances their power to control the population. It meets no resistance from the opposition, who promise to improve the ‘health of the nation’ even more.

Robin Fox, former editor of The Lancet describes Skrabanek as a “humorous man of immense culture and learning” in the Preface to The Death of Humane Medicine and despite not completely agreeing with Skrabanek’s pessimism, goes on to add that he “speaks many truths that we should heed”. I cannot help but feel that the world would be a better place if politicians, journalists and others did heed the words of this humorous, cultured medical man above the strident clamour of the health zealots. After all, without aggressive healthism there would be no need to insult our intelligence with pseudo-scientific policy based evidence and I sincerely doubt that the public would bemoan redundancies amongst the social “scientists”, non-practicing medics and psychologists who contribute to its socially divisive message. I doubt that these commenters on the BBC’s umpteenth plug for minimum pricing would mind at all:

For anyone who empathizes with Bauer and /or who is interested in a more liberal and less miserable future I recommend reading Skrabanek’s book which can be downloaded for free here.

By Chris Oakley. Chris’ previous posts on Liberal Vision include:  Alcohol is Old News – Minimum Pricing for Digestives is the “Next Logical Step” , Soviet Style Alcohol Suppression Campaign Called for By Public Health Activists , Alcohol Taxation: The truth, the whole truth and nothing but the truth Lies, damn lies, statistics &…

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Minimum Pricing– autocratic, badly researched, regressive & unchallenged by liberals.

By Guest
October 12th, 2012 at 3:31 pm | 4 Comments | Posted in Policy, pseudo science

It seems that the increasingly weak case for minimum pricing for alcohol is being promoted mainly on the basis of “something must be done and this is the something makes us look best” by those to whom gesture politics is second nature. Sadly that category appears to include allegedly liberal democrats.

As someone who prefers to drink alcohol socially rather than at home I have to admit to having been intrigued and initially quite positive about the concept. It was only after reading most of the 500 plus pages of poorly explained, opaque gibberish produced by the University of Sheffield on the subject that I came to realise how bad an idea it actually is

The theory that has been heavily sold to the public by politicians and the public health industry, supported by the BBC , can be summarised as follows:

  • Alcohol is price elastic so increasing the price of alcohol reduces consumption and small acceptable changes produce big effects.
  • At risk groups including heavy drinkers, binge drinkers and young drinkers tend to consume lower cost products.
  • Increasing the price of lower cost products therefore targets “problem” drinkers
  • As only lower cost alcohol is affected the impact on moderate drinkers is minimal
  • It’s all good so people will support the idea.

The problem is that it isn’t this simple as I will attempt to illustrate using examples from the Sheffield Study. The Sheffield team admit that one weakness in their analysis is that there is very little UK data to work with. However, amongst the few studies that they cite are two that appear to undermine the price elasticity theory that is the basis for their model:

“Reviews of demand models from 1989 and 1990 in the United Kingdom found that the demand for beer, wine, and spirits was generally price-inelastic, with the demand for wines and distilled spirits being more responsive to prices than the demand for beer (Godfrey 1989 1990).”

It is logical that at some point, price affects behaviour but the idea that small changes will have big effects is extremely suspect unless you ignore common sense and evidence to the contrary:

“Chaloupka and Wechsler (1996) used a questionnaire approach to explore likely reactions to a tenfold increase in the tax on beer and found it would reduce binge drinking by young women by about 20%, but would have no effect on young men.”

They concluded:

“A substantial tax increase is thus required to achieve modest reductions in binge drinking by female students.”

 With respect to minimum pricing targeting “at risk” groups:

“Wagenaar (2008) found in his meta-analysis that price/tax also significantly affects heavy drinking (p<.01), but the magnitude of effect is smaller than effects on overall drinking.”

Manning et al (1995) derived a price elasticity response function with respect to drinking quantile, indicating that moderate drinkers are the most price elastic”

“One study found that modest increases in levels of taxes have no effect on the number of drinks consumed or on binge drinking (6 or more drinks on one occasion) (Gius, 2002)”

And from Gallet (2007)

“Moreover, if we are particularly concerned with teenage drinking, since we find that teens are least responsive to price, then perhaps the best approach to reducing teen alcohol consumption should involve alternatives to taxation, such as education campaigns.”

So there is some evidence from the Sheffield study suggesting that price increases do not target the groups the politicians say that they do and that it is somewhat speculative, without the benefit of hard evidence, to claim that because those groups currently consume a disproportionate amount of the cheapest alcohol that increasing bottom end prices will change their behaviour.

The Sheffield team do acknowledge some quite significant discrepancies between their model and previous work. Faced with the fact that their methodology produces results inconsistent with other findings for price elasticity in heavier drinkers they do provide an analysis that is consistent with the literature…

“To enable more direct comparability with the estimates in the literature we have also generated elasticity estimates for total alcohol purchasing from the EFS, shown in Table 11. These are in broad agreement with the literature, showing that  - at the highest level of aggregation – hazardous and harmful drinkers (combined elasticity of -0.21) are less price elastic than moderate drinkers (elasticity of -0.47).”

….but then ignore it.

 “Note that these high-level estimates are provided for reference only and are not included in the model.”

This is an extremely important aspect of the whole exercise because if price elasticity is lower for people who are heavy consumers, the result of minimum pricing will not be a reduction in their consumption but a significant increase in the amount they spend with attendant social consequences for them and their dependants.

The high level analysis suggests that heavy drinkers are less than half as likely to change their habits as a result of price increases but even that may be misleading because the Sheffield team lump “hazardous” and “harmful” drinkers together in the analysis placing a man who drinks a couple of pints each evening in the same category as one who consumes a bottle of brandy a day.

“Hazardous” and “harmful” together with “moderate” are entirely arbitrary non-evidence based definitions that are used in rather cavalier fashion throughout the Sheffield study and apparently in subsequent media interviews. According to the BBC:

“This would reduce levels of alcohol consumption by 10.3% among harmful drinkers – those who drink above the recommended limit of 4 units per day for men or 3 units per day for women”

It appears that either an error prone BBC journalist or the Sheffield team themselves have chosen to broaden the definition of “harmful” to include “hazardous” drinkers. It should be pointed out to those unfamiliar with bizarre WHO definitions that the inappropriately named “hazardous” group is defined by the absence of any symptoms /ill effects making it very different from the “harmful” group.

I believe that there is strong evidence to suggest that the neat analysis presented by politicians and the public health industry is extremely questionable and that the claims made for minimum pricing are based not on evidence but on speculation. Furthermore, I believe that there is credible evidence that minimum pricing is a regressive tax that will impact lower income consumers of alcohol at any level and will have potentially serious impact on families of heavier drinkers on low incomes.

The politicians have certainly failed to convince the public on this subject.  A perusal of comments on even left wing media such as the Guardian and BBC shows consistent public antipathy towards the idea. It is a heavy handed statist solution to what most people view as a social problem that is more in keeping with soviet style government than liberal democracy. I am not surprised that it is advocated by the Marxist public health industry and most ardently supported by those on the far left such as Nicola Sturgeon and Kevin Barron, but I am amazed and disappointed by the absence of either a social or classical liberal political challenge to an illiberal regressive law that like many similar interventions is doomed to failure and unforeseen negative consequences.

Dodgy expenses are not the only reason why people don’t trust politicians.

By Chris Oakley. Chris has previously posted on Liberal Vision:  Smokers-State Approved hate and Intolerance is UK policy,   Alcohol is Old News – Minimum Pricing for Digestives is the “Next Logical Step” , Soviet Style Alcohol Suppression Campaign Called for By Public Health Activists , Alcohol Taxation: The truth, the whole truth and nothing but the truth , A Liberal Tolerant nation?What hope is there for liberty if truth becomes the plaything of political lobbyists , Public Health Success? & Lies, damn lies, statistics &….

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Lies, damn lies, statistics & meta-analysis – their contribution to the weak case for minimum pricing

By Guest
October 3rd, 2012 at 4:57 pm | 10 Comments | Posted in pseudo science

Few days go by without the public being subjected to some health scare or miracle cure delivered to them by an ill-informed but very enthusiastic media. Generally, these stories refer to “a new study” or “latest research” implying that “scientists”, “doctors” or “experts” have actually performed a novel experiment that has scientifically demonstrated something new and potentially useful.

In the vast majority of cases, this isn’t true. What has often happened is that a special interest group has reviewed some historical data, re-analysed it, applied a bit of spin in support of their case, published it somewhere not over insistent on scientific rigour such as a medical journal and issued a press release usually full of impressive sounding numbers.

These reviews appear in many formats but all suffer from the fundamental problem that they tend to conclude whatever the authors want them to. The most advanced form of this data manipulation epidemic is the meta-analysis, which can be viewed as a sort of amplifier. The idea is to take a number of studies that may be individually insignificant or even contradictory and combine them in a way that enhances consistencies.

Two major limitations of the approach as identified by numerous academic sources are publication bias and agenda bias. These factors are especially problematic in public health which is observably doctrinaire.

Publication bias normally refers to the tendency for positive results to be more likely to be published than those that support the null hypothesis thus distorting collective analysis of outcomes. Public health publications are often policy driven rather than objective or evidence based and the dogmatic nature of this approach fuels a more extreme form of publication bias caused by suppression of non-conformist ideas.

The depth of this problem was exposed in 2003 when the BMJ published Enstrom and Kabat whose work suggested that passive smoking appeared to be less lethal than previously claimed. The authors were set upon by the public health industry and The BMJ itself was subject to attack for its heretical challenge to public health orthodoxy. The vast majority of critics didn’t even address the content of the paper. The unsavoury incident led Ungar and Bray to write Silencing Science in which they conclude that an intelligent debate on the effects of passive smoke has become impossible. Irrespective of the debate over its content, the reception of the BMJ paper serves to illustrate the extreme extent of publication bias in public health.

Public health also suffers from agenda bias. The bedrock of science is sceptical objectivity and this is particularly important with meta-analysis because freedom to choose which studies to include, how to weight them and how to interpret the results introduces a degree of subjectivity.  In science the tendency to use this freedom to engineer favourable outcomes is usually offset by the value placed on scientific /academic integrity. Such ethical considerations are less restraining in public health where the discourse is dominated by policy driven orthodoxy rather than a desire for genuine discovery and the adversarial exploration of competing hypotheses.

In public health the authors of meta-analyses are all too often wishful thinking medics or public health activists who exhibit a depressing tendency to make the data fit the theory. Attempts to justify smoking bans by claiming dramatic post-ban falls in heart attacks have unsurprisingly produced some of the most unconvincing meta-analyses including this from Stanton Glantz a man obsessed by his personal war against tobacco and this produced by a cardiologist from Kansas

The outcomes of these meta-analyses are pre-determined by biased study selection. The authors chose to ignore the poor quality, methodological weaknesses and arguably fraudulent nature of the selected studies highlighting another weakness of meta-analysis. The authors should have been exposed by the “success” of their efforts which imply that 15-20% of heart attacks are caused by passive smoking. This is implausible to the point of being ridiculous but amazingly, their output is still referenced.

The dubious use of meta-analysis is not confined to tobacco control. Many of us have been left scratching our heads by claims made for minimum alcohol pricing. The notion that a modest financial measure that would not inconvenience the majority could have a significant impact on problem drinking and youth drinking appears counterintuitive and depends on some odd assumptions about price elasticity and behaviour.

The politician’s claims are based on the work of Petra Meier who derives much of her theory from meta-analyses. Based on Gallet’s 2007 interpretation of 132 studies dating back to 1945 she concludes “if the price of beer is raised by 10%, beer consumption would fall by 3.5%; if the price of wine was increased by 10%, wine consumption would fall by 6.8%; and if the price of spirits increased by 10%, spirits consumption would fall by 9.8%.”

In some ivory towered fairyland perhaps but in real life here in the UK, the leap from Gallet’s findings to “A 50p limit should cut alcohol consumption among moderate drinkers by about 3.5%, or half a unit for women and two-thirds of a unit for men” together with rest of the hyperbolic nonsense in this fabulously biased BBC article is hard to understand or justify.

I can imagine the Scottish government falling for this on the basis that any data however ridiculous is an improvement when you are used to your health secretary simply making up the numbers to support her agenda, but surely David Cameron should be better advised than this?

Reading Craig Gallet’s 2007 paper on which Meier relies heavily and being mindful of her claims with respect to targeting young drinkers, I was struck by a line in the conclusion:

“… if we are particularly concerned with teenage drinking, since we find that teens are least responsive to price, then perhaps the best approach to reducing teen alcohol consumption should involve alternatives to taxation, such as education campaigns.”

This is not the only inconsistency in this classic case of torturing the numbers to fit pre-determined policy.

By Chris Oakley. Chris has previously posted on Liberal Vision:  Smokers-State Aprroved hate and Intolerance is UK policy,   Alcohol is Old News – Minimum Pricing for Digestives is the “Next Logical Step” , Soviet Style Alcohol Suppression Campaign Called for By Public Health Activists , Alcohol Taxation: The truth, the whole truth and nothing but the truth , A Liberal Tolerant nation?What hope is there for liberty if truth becomes the plaything of political lobbyists and Public Health Success?

Note from Editor

You might also find the following posts interesting:

BBC And Guardian Played Like Fools On Minimum Alcohol Pricing by Dick Puddlecote 3/10/2012

A black market in booze fearmongering by Chris Snowdon for Spiked! 3/10/12012

Lies, Damn lies and Sheffield University by The Pub Curmudgeon 3/10/2012

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Epidemiology – Splitting the atom with a breadknife?

By Guest
August 30th, 2012 at 8:58 am | 1 Comment | Posted in health, pseudo science

“If your experiment needs statistics, you ought to have done a better experiment” – Ernest Rutherford

Statistics are so ingrained in so many aspects of our lives that it is sometimes hard to believe that the statistical approach is a relatively new phenomenon which is far from beyond criticism. It has dominated medical research and practice only since the mid-20th century but is now the principle means by which new pharmaceuticals are judged and the basis for many public health claims.

One major problem with over reliance on the statistical approach is that it fails to adequately take into account our individuality and diversity. Human beings vary enormously in both nature and biology. Our individual biology dictates how we respond to drugs and our individual nature determines how we respond to public health initiatives.

Liberals question the statistical approach to public health because it often seems clumsy and heavy handed, offering poorly defined benefits to the few at the expense of the freedoms of the many.

Medics question the value of new drugs whose efficacy is judged by small statistical effects in large scale clinical trials because whilst these drugs may benefit some patients, the chances are that in many cases they will have no significant effect.    

In recent years, growing investment in personalized medicine has begun to challenge the dominance of the statistical approach. The idea is to treat patients as individuals based on their unique genetic make-up and thus offer “the right treatment to the right person at the right time”. As we move further down the personalized medicine path it is likely that medics will further challenge the value of the statistics based approach to their profession. One medic who certainly does is James Penston, author of stats.con

Penston believes that the statistical approach to medicine is flawed and uses both epidemiology and randomized control trials to illustrate his point.  His chapter on epidemiology subtitled The Study of Scare Stories is particularly damning. He concludes:

“People are right to be sceptical about medical research. Cohort and case-control studies, and those who promote them, deserve the scorn heaped upon them. A sensible approach to epidemiological studies would be to ignore the results altogether.”

A bit extreme perhaps but he does make a coherent case based on essential weaknesses in the approach and the tendency to place far too much emphasis on very small effects derived using imprecise methods.  The reality is that aside from establishing a link between smoking and lung cancer 60 years ago, epidemiology can claim very few successes but this has not deterred the media or the public health industry from bombarding us with statistics and exaggerated claims. It is difficult to take seriously risk factors calculated to x decimal places that are based on individuals responses to questionnaires. Do people really tell the truth about their lifestyles? Can they remember what they did 10 years before their illness began? Are these precise claims really justifiable?

The frequent misuse of the epidemiologist’s efforts by others contributes to epidemiology’s poor reputation as does its coverage in the media.  For example, this BBC article claims to report Tim Key’s study on lifestyle factors and circulating sex hormones in post-menopausal women. Key observed that elevated hormone levels, which are one risk factor for breast cancer, are more closely associated with obesity than other lifestyle factors such as smoking and alcohol. The BBC article is so poorly written that the reader is likely to be misled into believing that obesity is the major cause of breast cancer “shortly followed” by alcohol and smoking. That is not what Key studied but many more people will have read the BBC article than will have read the original paper. This is unfortunate because the contrast between Key’s carefully worded conclusions and the journalist’s interpretation is important.

Bearing in mind the large sums of research funding at stake, the constant meddling of politicians, the evangelical fervour of pressure groups and the ignorance of the media, it is perhaps not surprising that the importance of small epidemiological effects is often exaggerated for public consumption. 

One very common method used to achieve impact far greater than the actual significance the data merit is to emphasize changes in relative rather than absolute risk. Using relative risk makes headlines but is often fairly meaningless at the individual level. For example, if a person’s  risk of contracting cancer A is 0.01% and a study shows that eating bacon increases that risk by 20%, then the bacon eater increases his actual risk of developing cancer A to 0.012%. The 20% headline is eye catching but most people would not give up bacon based on these odds.

Penston highlights cohort size as another factor misused by statistics adherents. It is an indication of just how dominant the statistical approach has become that we tend to be impressed by studies involving large numbers of people when the real benefit of such numbers is to achieve statistical significance for effects that are otherwise too small to be meaningful.

In a society that allegedly values individual freedoms should we really be basing policy on data that is all but meaningless to the individual and effects that require tens of thousands of subjects to achieve even the smallest significance?

Although I respect the work of some epidemiologists I have to ultimately agree with Dr Penston’s criticism of their collective output because the exaggerated, over-precise claims made by the media and public health industry contrast so sharply with the bluntness of the tools at the epidemiologist’s disposal that they can be reasonably equated to claiming to have split the atom with a breadknife.

By Chris Oakley. Chris has previously posted on Liberal Vision:  Smokers-State Aprroved hate and Intolerance is UK policy,   Alcohol is Old News – Minimum Pricing for Digestives is the “Next Logical Step” , Soviet Style Alcohol Suppression Campaign Called for By Public Health Activists , Alcohol Taxation: The truth, the whole truth and nothing but the truth , A Liberal Tolerant nation?What hope is there for liberty if truth becomes the plaything of political lobbyists,  Public Health Success? and Could the increasing popularity of harm reduction products impact cigarette consumption?

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