The Prosecutor’s Phallusy

October 28th, 2006 by Ben Goldacre in bad science, statistics | 82 Comments »

Ben Goldacre
Saturday October 28, 2006
The Guardian

There once was a time when your biggest worry, as a paediatrician, was being lynched by a herd of illiterate tabloid readers; but if you’re Professor Sir Roy Meadow you get scapegoated by the innumerate too. First he was struck off by the GMC for giving flawed evidence as an expert witness in the Sally Clark trial. Then he won an appeal. And now, this week, he’s half lost it again.

But what if the flaws in his evidence weren’t his fault alone? In the Sally Clark case, where two children in the same family had died, Meadow quoted “one in 73 million” as the chance of two children in the same family dying of Sudden Infant Death Syndrome (SIDS). This was a problematic piece of evidence for two very distinct reasons: one is easy to understand, the other is an absolute mindbender, but if you can concentrate, for three short minutes on a Saturday morning, I can prove that you are smarter than Professor Sir Roy, the judge in the Sally Clark case, her defense teams, the appeal court judges, and almost all the journalists and legal commentators reporting on the case.

We’ll do the easy problem first: the figure itself is iffy, as everyone now accepts. It was calculated as 8543 x 8543, as if the chances of two SIDS episodes in this one family were independent. This feels wrong from the outset, and anyone can see why: there might be environmental or genetic factors at play, both of which would be shared in the same family. But forget how pleased you are with yourself for understanding that fact. Even if we accept that two SIDS in one family is much more likely – say, 1 in 10,000 – any such figure is still of dubious relevance.

The action is in what we do with this spurious number. Many press reports at the time stated that one in 73 million was the chance that the deaths of Sally Clark’s two children were accidental: that is, the chance that she was innocent. Many in the court process seemed to share this view. The factoid certainly sticks in the mind. But this is an example of a well known and well documented piece of flawed reasoning known as the “Prosecutor’s Fallacy”.

Two babies in one family have died. This in itself is very rare. Once this rare event has occurred, the jury needs to weigh up two competing explanations for the babies’ deaths: double SIDS or double murder. Under normal circumstances – before any babies have died – double SIDS is very unlikely, and so is double murder. But now that the rare event of two babies dying in one family has occurred, the two explanations – double murder or double SIDS – are suddenly both very likely. If we really wanted to play statistics, we would need to know which is relatively more rare, double SIDS or double murder.

Not only was this crucial nuance missed at the time, it was also clearly missed in the appeal: they suggested that instead of “1 in 73,000,000″ Meadow should have said “very rare”. They recognised the flaws in its calculation – the easy problem above – but still accepted it as establishing “a very broad point, namely the rarity of double SIDS.” But that was wrongheaded, and rarity is irrelevant, because double murder is rare too. The appeal court thought Meadow had maybe got the number of millions wrong, when in fact the precise figure was a side issue: and an entire court process failed to spot the nuance of how the figure should be used.

Twice.

If it is true that Meadow should have spotted and anticipated the problems in the interpretation of his number, then so should the rest of the people involved in the case: a paediatrician has no more unique responsibility to be numerate than a lawyer. The Prosecutor’s Fallacy is also highly relevant in, for example, DNA evidence. Anyone who is going to trade in numbers, and use them, and think with them, and persuade with them, and lock people up with them, also has a responsibility to also understand them, and as you’ve just seen it’s hardly rocket science. But paediatricians aren’t just lynched by the illiterate herd: in this case, one was scapegoated by the innumerate.

Another way of looking at this interesting problem is…

Let’s say you come across two arrows stuck in a wall, a millimetre apart. I am standing next to the wall with a bow and arrow looking well pleased with myself. Am I a good archer? Your answer depends on the context. If there is one target drawn on the wall, and it was drawn before I got there, and I fired my two arrows dead into the centre of the bullseye, then there is little doubt that I am a total gangsta.

If, on the other hand, the wall is massive, and filled with tens of thousands of arrows that I’ve been firing into it over the course of many years, then the fact that there are two adjacent arrows here and there is not headline news. If I came along and drew a target around the two that are close together, you wouldn’t congratulate me on my archery skills.

That, I’ll say it again, is the irrelevance of the one in 73 million figure, even if it were a valid estimate.


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82 Responses



  1. Bob O'H said,

    October 28, 2006 at 9:29 am

    This all stirred the Royal Statisical Society into action, writing a letter to the Lord Chancellor, and press release. Oddly enough, the home secretary at the time is a member of the RSS.

    Bob

  2. Dyscolus said,

    October 28, 2006 at 11:25 am

    What is worse, almost every newspaper did something like this:

    “A crucial part of Prof Meadow’s testimony was that the chances of two babies in a family dying of cot death were one in 73m. But he failed to take into account 25 years of research that put the risk at one in 77.”

    www.guardian.co.uk/uk_news/story/0,,1513878,00.html

    “Sally Clark, a solicitor from Cheshire, was jailed largely on the paediatrician’s now infamous assertion that the chance of two babies dying of cot death within an affluent family was one in 73 million.

    The real figure was one in 77.”

    www.telegraph.co.uk/news/main.jhtml?xml=/news/2005/07/14/nmead14.xml

  3. Malcolm the Lurker said,

    October 28, 2006 at 11:31 am

    Ben

    I’m embarrassed that along with the rest of the English legal system I had not worked that one out myself, but I do work in manufacturing, surrounded by dodgy statisticians (Six Sigma Black Belts!). Is Six Sigma as bad science of interest to anyone? I have read quite a few decent debunking articles but the consultants’ gravy train seems to roll on with a statistically illiterate senior management accepting all sorts of nonsense eg we recorded 3.4 ppm defects, therefore our process has a capability of 6 sigma. What!
    Apologies for invading your world from mine, but crap statistics are everywhere.

    Malcolm

  4. Ben Goldacre said,

    October 28, 2006 at 11:33 am

    yeah, one in 77 is obviously ridiculous, but in any case would not be the odds of clark’s innocence. even if one in 73 million were a valid estimate of the risk of two SIDS in one family, it would still be a total red herring of a figure.

    another way of looking at this interesting problem is:

    let’s say you come across two arrows stuck in a wall, a millimetre apart. i am standing next to the wall with a bow and arrow looking well pleased with myself. am i a good archer? your answer depends on the context. if there is one target drawn on the wall, and it was drawn before i got there, and i fired my two arrows dead into the centre of the bullseye, then there is little doubt that i am a total gangsta.

    if, on the other hand, the wall is massive, and filled with tens of thousands of arrows that i’ve been firing into it over the course of many years, then the fact that there are two adjacent arrows here and there is not headline news. if i came along and drew a target around the two that are close together, you wouldn’t congratulate me on my archery skills.

    that is the irrelevance of the one in 73 million figure, even if it were a valid estimate.

  5. RS said,

    October 28, 2006 at 12:02 pm

    I’m amazed you got through that whole article without mentioning the Revd Bayesand the difference between the prior and posterior probabilities. And that is something that has been brought up in court before (e.g w.r.t. DNA evidence), and I think a judge really should know something about it, as should a paediatrician with a forensic role.

  6. billgibson said,

    October 28, 2006 at 12:02 pm

    This all gets even more silly when we involve the article on page 31 (about a national DNA database). The media will often quote evidence from criminal trials, saying that the odds of someone’s DNA matching that found at a crime scene by chance is “millions to one”. It doesn’t take a statistical ninja with extra kung-fu analytical moves to work out that if every bugger in the country has their DNA compared to a forensic sample, you’ll get a fair few matches just by chance.

    And given the abject idiocy Ben was taking about a couple of weeks ago with PCR (www.badscience.net/?p=313), this may all go very wrong indeed.

    Bill

    PS Completely off topic, but I’m waiting for my results for the MRCP. Lots of good vibes from the badscience MBChB crew would be appreciated 8~). If I do pass, I can write it up in an alternative health journal to say it was the vibes which made the difference – it’s about as valid as a trial as the Durham fish saga……

  7. RS said,

    October 28, 2006 at 12:10 pm

    DNA databases are even better than that, at the moment most people on them are criminals, or have had some contact with the police, so they’re already tainted, get a match and you’re screwed.

  8. Dr Aust said,

    October 28, 2006 at 12:26 pm

    bill

    I can think of another interesting Alt study for MRCP pass rates. The Q is, does PRAYING for a pass makea difference? And is there a difference between praying for your own pass, and “being prayed for”…

    …I think we should be told.

  9. james++ said,

    October 28, 2006 at 12:38 pm

    I met a guy the other day who claimed he was Irish.
    ‘Proably a liar’, I thought to myself. There is only a 1 in 750 chance that we was telling the truth.

  10. eponerd said,

    October 28, 2006 at 3:42 pm

    Sorry, Ben, but while I tend to agree that not just Sir Roy was at fault, he has hardly been scapegoated. Surely the point here is that he was asked a question which was outside his remit and should have refused to speculate on the subject. The cobbler, as the saying has it, should stick to his last. The defence is probably also at fault here for not making such an objection at the time (assuming they did not – I have not read the transcript).

    Professor Meadow was called for his expert opinion as a paediatrician, surely, not as a statistician. If it is considered that there was no supporting evidence of abuse, smothering or poisoning or any history of Munchausen by proxy, his ill-advised reply arguably swung the trial in the direction of a guilty verdict and a guilty verdict was the result, based upon entirely speculative and circumstantial grounds (note that I do not dignify such speculation as ‘evidence’).

    Perhaps a further lesson here is that, just as correlation is not the same as causation, the argument that an event is statistically unlikely does not mean that it is impossible. In delicate cases such as this one, such speculative matter should be rigorously excluded in the absence of other forensic evidence.

  11. Teek said,

    October 28, 2006 at 4:10 pm

    good points Ben, many of us are as innumerate as the lawyers and ‘expert witnesses’ in this case but can still work out that even tho the chances of double homicide/double accidental death are rare in the population as a whole, there’s a pretty good chance that in families where two kids have died, it’s because of either of these possibilities.

    thing is, lawyers often do understand numbers, vey well. however, they also understand that Joe Public doesn’t. lawyers all to often spit numbers and probabilities at juries knowing full well that the chosen 12 won’t have a clue… i was on a jury at the Old Baliey two years ago, dealing with a particularly nasty rape case. the prosecution lawyers presented ‘DNA evidence’ showing that the suspects’ DNA matched that found at the scene. problem was, the jury was convinced that this means the suspects were, unequivocally, undoubtedly, guilty. altho we convicted the accused, it took me an hour to explain to the jurors that just because the chances of a match are millions to one, because of the way the DNA fingerprinting works it is by no means failsafe.

  12. Ben Goldacre said,

    October 28, 2006 at 7:52 pm

    “Sorry, Ben, but while I tend to agree that not just Sir Roy was at fault, he has hardly been scapegoated. Surely the point here is that he was asked a question which was outside his remit and should have refused to speculate on the subject.”

    well hang on, he gave a figure which everyone wrongly imagined was pertinent to the case (and he gave it with references, albeit fairly shaky ones). meadow is no more guilty of failing to spot the prosecutor’s fallacy than anyone else involved n the case including the defense. a paediatrician has no special responsibility to know about the prosecutor’s fallacy, in fact he’s far less likely to have encountered it as a problem than people routinely involved in the court process.

    he has been very specifically singled out over this issue, remember, Roy Meadow was struck off the GMC register and forbidden to practise medicine, and it is popularly and incorrectly believed that his flawed evidence was the crucial element that got sally clark out of prison at the appeal.

    in fact this is untrue. the main ground for sally clark’s appeal was the failure by home office pathologist Dr Alan Williams to disclose to the court test results which showed the presence of Staphylococcus aureus in tissue samples from Harry Clark’s body (raising the possibility that he had died from natural causes). Dr Alan Williams was brought up before the GMC but not struck off.

    have you EVER heard of Dr Alan Williams? no. why was Meadow singled out?

    many people think a lot of the groundswell of hatred against him probably has to do with his work on “munchausens syndrome by proxy” (non-accidental injury of children by parents). if you google him you’ll certainly find a lot of negative material directed at him for that.

    it’s a controversial area to work in culturally and personally, i make no comment on the rights or wrongs of anything he’s done in the field (not something i know much about), i just wonder if the hatred directed towards him from his work there bled over into his unique vilification around the Clark trial. otherwise it’s hard to explain.

  13. Moganero said,

    October 29, 2006 at 8:32 am

    Ben said:
    “If there is one target drawn on the wall, and it was drawn before I got there, and I fired my two arrows dead into the centre of the bullseye, then there is little doubt that I am a total gangsta.”

    Or it was a lucky fluke.

    Once while my two drinking companions were at the bar, which was in a different room in the pub, I scored three bulls with three darts. They didn’t believe me, and I don’t blame them, as it was total fluke as my normal hitrate would be about 9 out of 10 – and that’s of the board not the bull!

    Not being any kind of statistician or mathemetician, I wouldn’t be able to define a fluke in those terms – is there a definition of it?

  14. Moganero said,

    October 29, 2006 at 8:33 am

    Ben said:
    “If there is one target drawn on the wall, and it was drawn before I got there, and I fired my two arrows dead into the centre of the bullseye, then there is little doubt that I am a total gangsta.”

    Or it was a lucky fluke.

    Once while my two drinking companions were at the bar, which was in a different room in the pub, I scored three bulls with three darts. They didn’t believe me, and I don’t blame them, as it was total fluke as my normal hitrate would be about 9 out of 10 – and that’s of the board not the bull!

    Not being any kind of statistician or mathemetician, I wouldn’t be able to define a fluke in those terms – is there a definition of it?

  15. doctormonkey said,

    October 29, 2006 at 11:47 am

    i dislike the fact that a paediatrician was struck off not for a flaw in his paediatrics or doctoring but his statistics and statistical analytical abilities. if the defence had called a statistician or even a doctor who specialises in such things as population medicines rather than making babies better they could/should have easily refuted his evidence – why was it unchallenged?

    oh and good luck with the evil MRCP i am waiting a bit before i try it – too evil for me for now!

  16. BrickWall said,

    October 29, 2006 at 11:54 am

    Re posts 10 and 12. Whilst I take your point Ben on comparable treatment of Dr Williams to Prof Meadows. The issue of Prof Meadows screw up is surely that notion of being the “expert” witness that brings him in to starker view. It can’t be excusable in a court of law for someone to give evidence as an expert that they don’t understand and is outside of their specialism, and be excusable because everyone else thought that too (you and I didn’t?), he was representing himself as the expert on that issue.

    Obviously there is the utter failure of the defence counsel to bring in an expert (perhaps yourself Ben?) to counter the prosecution expert that should also be addressed, not to mention the whole court systems dodgy use of paid “experts”. Try joining one of the organisations for expert witnesses, whilst your dead cat might not get in I’m pretty sure Gillian McKeith could!!!

  17. Ben Goldacre said,

    October 29, 2006 at 12:16 pm

    brickwall: we are talking about a piece of flawed reasoning SO tricksy that not only did meadow fail to notice it but the entire court process failed to notice it, and i bet you almost everyone reading my column only noticed it for the first time there. in a sense they all fell for the cognitive equivalent of an optical illusion. that puts it in the category of understandable human cockup, and if you want to strike off all doctors from medical practice for that then you’re going to find a lot of newly rich NHS doctors working in city jobs wondering why they never changed profession earlier.

  18. andrew said,

    October 29, 2006 at 12:38 pm

    “You know, the most amazing thing happened to me tonight. I was coming here, on the way to the lecture, and I came in through the parking lot. And you won’t believe what happened. I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing! ”

    Quote by R. Feynman, (possibly)

  19. BrickWall said,

    October 29, 2006 at 1:11 pm

    Ben,

    Sorry to drag same issue on but the silly stat of 1 in whatever million it was and how it was arrived at wasn’t an optical illusion. And someone of his standing and being prepared to send someone to jail for murder on the basis of it surely should have not let that slip by?

    I guess my thinking would then be that as an expert who did use that daft figure how much thought was then given to what and how it should be used in context – not very much I would suggest.

    I don’t think these issues alone should lead to him being struck off from medical practice ~(was anything else considered by the GMC?) but they should raise questions about him standing in court as an expert. Surely one aspect of being good at what you do (an expert indeed) is to be aware of what you don’t know and be prepared to say so. I wonder if this could be taken on as a further stream of enquiry for you – the regulation (or lack there of) of expert witnesses. A field where our public, lay perception would like to believe an expert standing in court is just that and perhaps it is this perception that led to no one in the court system being adequately equipped or prepared to challenge at the time?

  20. Dr Bollocks said,

    October 29, 2006 at 4:50 pm

    Ben,

    Good article with excellent points.

    However, for the benefit of BrickWall and many others: the issue of SIDS was entirely irrelevant to the case. A diagnosis of SIDS can only be made when there is an absence of pathological findings. In the Clark case, there were several abnormalities at the autopsies. Obviously, the significance of those findings was the subject of much dispute and formed the basis of her, ultimately successful, appeal. Neither prosecution nor defence argued that SIDS was the cause of death.

    The now notorious SIDS statistics should never have been raised. If I recall correctly, the judge at the original trial instructed the jury to ignore this particular issue.

  21. kim said,

    October 29, 2006 at 9:00 pm

    Surely one of the problems with the Sally Clark case is that SIDS is, almost by definition, a death for which there is no explanation. A baby dies of no obvious cause such as (say) illness or suffocation and we call it SIDS.

    My memory of the particular context of the case is this. For a few years before the Clark case researchers had been working on the belief that there was a genetic component to SIDS. An American woman had lost seven babies to SIDS, suggesting a strong genetic basis, and prompting researchers to look for the link. It turned out, however, that she had actually murdered the children, which prompted a backlash against the genetic theory and made people start wondering whether other supposed SIDS cases were actually murders. Roy Meadows was clearly influenced by that change in thinking.

    My own view, FWIW, is that he was so taken by this idea that SIDS victims had actually been murdered by their parents that he no longer weighed the evidence up in a proper scientific manner, ie he saw murder everywhere and was willing to distort the evidence to suit his particular prejudice. The Clark case wasn’t the only case where he did that. For that reason, I do think he was culpable because he failed to give a balanced view. In an area such as SIDS, which is fraught with doubt and disagreement, that seems highly reprehensible.

  22. Michael Harman said,

    October 29, 2006 at 11:39 pm

    kim is right – Meadows stopped taking an objective view and became convinced that his view was right. After all, his attitude was summed up in what has become generally known as the eponymous ‘Meadows’ law’ – ‘one cot death is tragedy, two is suspicious and three is murder, unless proven otherwise’.

  23. john souray said,

    October 30, 2006 at 10:16 am

    Two other points: Suppose for a second that the 73 million calculation had been correct. The world’s population is about 6.5 billion. Even allowing for the probability that many of those live with judicial systems that are not that bothered, or even no judicial system at all, still it seems clear to me that this unlucky 1 in 73 million chance must come up several times in each generation (somewhere in the world), just as though the odds of winning the lottery are 14 milion to one, nevertheless one or more people win it nearly every week.

    The proper question for the jury would have been, colloquially: “Yeah, yeah, we understand why they are here facing a trial. But now that you’ve got them here what evidence have you got that ths isn’t an instance of that 73 million to one chance?”.

    73 million is just not that big a number.

    I’m glad too to see “Meadow’s law” quoted, as I couldn’t quite remember the wording. This too is clearly specious reasoning that you don’t have to be a statistician to see through.

    Where three children in the same family die, I’m not aware that it has ever happened that all three die on the same night. So before three children can die, then first two (suspicious) and before that one (tragedy) must happen. But the claim usually made is that all three were murdered. Clearly then, if this “law” is taken seriously Meadow must admit that he has been misidentifying causes of death, as the initial “tragedy” is reclassified in the light of subsequent events. Of course, this theory could be preserved by claiming that what’s actually happening is that the idea of killing the third child is planted in the mind of the parent by the terrible tragtedy of the first. What about the second? Well, er, I suppose sometimes it’s one, sometimers it’s the other. But I don’t think it’s necessary to go further, as the absurdities lurking within this reasoning are becoming clear.

    There is a common theme to both these points (the long odds, and the three times is murder). Both might be legitimate grounds for prompting an investigator to look more closely. But the reason the investigator should look more closely is in order to find forensic evidence that is relevant to the case and which could be put in front of a court. The staistical causes of these suspicions are in themselves worthless, and should never have been allowed in the court at all.

  24. eponerd said,

    October 30, 2006 at 11:29 am

    Okay, Ben, maybe I am prepared to agree he was witch-hunted out of the profession. Whether it was because of his Munchausen work I am not qualified to speculate.

    I tend to agree with doctormonkey that his being struck off for this was harsh, but he set himself up as an expert in the matter and arguably should have been more cautious.

    Can I make a plea for a legal system which is based upon evidence and not speculation? The problem here, of course, is that once a spurious but entirely ‘scientific’-sounding piece of bollocks like this has been uttered in court it is difficult to unsay it. The jury will often then be swayed by it, even in the face of admonishments by the judge that it is irrelevant. Unfortunately, both defence and prosecution will often introduce said bollocks because it favours their case.

    Unfortunately, these days even that which many people regard as ‘hard’ evidence is subject to a ‘statistical’ approach: both DNA and fingerprint evidence is often used on the basis of a certain number of ‘points of comparison’, as a full and unambiguous match is unavailable. In these cases there is always a statistical chance (however small it might be) that the apparent match to a suspect is erroneous. That being said, these techniques are arguably still less suspect and more reliable than Roy Meadow’s statistics.

    Oh well, at least we are not yet in the realms of Philip K. Dick’s ‘Minority Report’… Pre-crime, anyone?

  25. hyperdeath said,

    October 30, 2006 at 11:50 am

    The police should crack down on the so-called “winners” of the National Lottery. The probability that they won by chance is only one in fourteen million, and so they must be guilty of fraud.

  26. Dr Aust said,

    October 30, 2006 at 12:48 pm

    Nice one, Hyperdeath. Great analogy, almost exactly analogous to the Meadow one, in fact.

    Would make a great “teaching example” of why his logic, and that of the people relying on his view (or at least their interpretation of it) was flawed.

  27. billgibson said,

    October 30, 2006 at 1:35 pm

    People have a tendency to make connections and links, and assume unrelated things are connected. A good example is the Chip-and-Pin card.

    Imagine you apply for two credit cards – maybe you’ve overspent on omega-3 in Holland and Barrat – and when they arrive they have identical PINs. I think a large proportion of the general public would be worried by this and phone the bank, assuming some fraud or error. In fact the chance of two cards having the same 4-digit pin is only 10,000:1 against, and is bound to come up fairly regularly in a large enough population.

  28. simongates said,

    October 30, 2006 at 1:58 pm

    Re post 24: the Campbell Collaboration are working for evidence based justice – see www.campbellcollaboration.org/CCJG/index.asp

    Also woefully inadequate guidance from the Crown Prosecution Service on the prosecutor’s fallacy:
    www.cps.gov.uk/legal/section13/chapter_f.html#_Toc7839912

    It seems to me that an expert witness like Sir Roy has an obligation to ensure that what he or she says in court is correct, as the consequences of getting it wrong can be pretty catastrophic, although not usually for the witness. I believe it’s correct to say that medical expert witnesses are also paid for their services (can anyone confirm?), which makes sloppiness even more inexcusable.

  29. billgibson said,

    October 30, 2006 at 2:03 pm

    My neighbour the forensic pathologist calls expert witnesses “liars for hire”. They aren’t independant, each one is paid by one side to give an opinion.

  30. Dr Aust said,

    October 30, 2006 at 6:03 pm

    Quite so, Bill

    This is of course one of the downsides of the adversarial judicial system used in the UK and US, rather than the “investigating magistrate” system the French use.

    The prosecutors want to convict. The defence want to get their client off. Both will have a major interest in sourcing “expert opinion” that will support their overall objective. Medical negligence cases often feature “experts for hire” who make a decent living delivering these opinions.

    Of course, all experts are not equal. The value for the prosecution in a criminal trial of producing an expert titled “Professor Sir Something Something” giving an expert opinion doesn’t just lie in the opinion. It also lies in the perceived eminence of the expert witness, and thus the reliability / weight the jury tends to place on his/her evidence. Under these circumstances the defence needs not just an expert to dispute the first expert’s view, but probably someone of equal “credentialled-ness”. In effect, the jury are often going to be basing their view on the expert, not the evidence.

    Of course, if the expert makes clear errors, then the defence lawyers (and presumably their experts) SHOULD spot them, and could then use them in cross-examination of the expert to rebut the expert’s testimony, or in their own arguments. As I read Ben’s article he was pointing out that this hadn’t happened in the Sally Clark trial, even though the statistical errors in Sir Roy’s evidence were fairly straightforward.

    Of course if the experts are not challenged expertly the cases can seem to come down to exactly which experts, saying what, the jury hear. Several of the recent high-profile cases have featured conviction based in part on expert medical testimony, and then later a campaign based on other experts saying “but there could have been other explanations….” (see e.g. the salt poisoning case against Ian and Angela Gay).

    The question is who you blame for the jury not hearing these other expert views at the trial. Not a simple question to answer.

  31. Andrew Clegg said,

    October 30, 2006 at 6:43 pm

    John Souray sayeth:

    “Two other points: Suppose for a second that the 73 million calculation had been correct. The world’s population is about 6.5 billion. Even allowing for the probability that many of those live with judicial systems that are not that bothered, or even no judicial system at all, still it seems clear to me that this unlucky 1 in 73 million chance must come up several times in each generation (somewhere in the world), just as though the odds of winning the lottery are 14 milion to one, nevertheless one or more people win it nearly every week.”

    Surely, you shouldn’t be comparing the 73 million to the 6.5 billion, but to the number of parents who have more than one child, or something like that?

    Andrew.

  32. Andrew Clegg said,

    October 30, 2006 at 6:44 pm

    … or even the number of parents with more than child who’ve suffered more than one infant death..?

  33. Gleamhound said,

    October 30, 2006 at 6:45 pm

    Badscience aside, if Sally Clarke’s defence (or the judge) had done their job and taken Meadow up in the court room about his statistical howler, then their would have been some red faces and it would have been forgotten 5 minutes later. It is interesting that no-one seems to have thought of disciplining Clarke’s council for incompetence.

  34. Ben Goldacre said,

    October 30, 2006 at 7:21 pm

    it’s been very interesting to watch wealthy lawyers fall over themselves to criticise medical expert witnesses in the wake of this shared error. there was one on the radio this morning talking about how medical expert witness activity should be some kind of compulsory part of doctors’ NHS work as it’s a public service. personally i’d like to see the legal profession nationalised, it’s a huge dent in the nation’s resources that’s often quite unnecessary, and it would be much more efficient: the huge drop in their salaries and far bigger workload would more than make up for any public sector management failings.

  35. RS said,

    October 30, 2006 at 7:23 pm

    Lawyers have retained self regulation to an even greater degree than doctors.

  36. john souray said,

    October 30, 2006 at 7:24 pm

    Andrew Clegg says: “Surely, you shouldn’t be comparing the 73 million to the 6.5 billion, but to the number of parents who have more than one child, or something like that?”

    But the number of parents who have more than one child is a subset of the 6.5 billion, and my point is that though I wouldn’ t know where to begin in accurately estimating exactly how many there are, it is going to be a large subset, and certainly much bigger than 73 million.

    In any case, I’m most explicitly not attempting to produce an accurate probability to lay in front of a court. My whole point was that the very character of this probabilistic evidence is not fit to be put in front of a jury.

  37. superburger said,

    October 30, 2006 at 10:07 pm

    don’t let me be the first to say it.

    “There’s lies, damned lies and there’s statistics”

  38. wewillfixit said,

    October 31, 2006 at 9:29 am

    And 87.32% of statistics are made up on the spot.

  39. Evil Kao Chiu said,

    October 31, 2006 at 11:24 am

    “Personally i’d like to see the legal profession nationalised, it’s a huge dent in the nation’s resources that’s often quite unnecessary, and it would be much more efficient: the huge drop in their salaries and far bigger workload would more than make up for any public sector management failings.”

    God, I hate it when humanities grads trespass on areas they don’t really understand. Oh, wait. I meant ‘science graduates’.

  40. hyperdeath said,

    October 31, 2006 at 11:40 am

    “And 87.32% of statistics are made up on the spot.”

    And 78.4569291% of statistics are quoted to a greater degree of accuracy than can be justified by the methodology used.

  41. Jonny said,

    October 31, 2006 at 12:32 pm

    Has anyone pointed out the inherent contradiction yet in the phrase ‘illiterate tabloid readers’? No? Just me then. Apologies for being such a pedant, but as so many of your very useful articles highlight daft things said by others, I think it’s important that you don’t say anything daft yourself.

  42. jdc325 said,

    October 31, 2006 at 1:16 pm

    Doesn’t it depend on your definition of literacy? As I understand it, different societies may have different definitions – for example, literacy may be defined as:
    “The ability to read and write and use numeracy, to handle information, to express ideas and opinions, to make decisions and solve problems, as family members, workers, citizens and lifelong learners.”

  43. Dr Aust said,

    October 31, 2006 at 2:20 pm

    Re. lawyers…

    Problem is, since going to law is the “final recourse” in all sorts of areas of life, the law is, as Al Pacino’s character puts it in the wonderful “The Devil’s Advocate”, “the ultimate backstage pass”…so lawyers are inescapable.

    Plus in most scenarios related to the organisations /businesses non-lawyers work in, m’learned friends are acting as “external consultants” , and are billing by the hour. In contrast, if it is (for instance) a student and their family sueing the University, the plaintiffs give their time, the unfortunate organisation on the receiving end gives its employees’ time, all for no recoverable money (except in the case of a large judgement at the end). But the lawyers get theirs…. ker-ching.

    Now, to some extent this is a function of the way the system is constructed: that people can sue each other, or organisations, is part of having a legal system to govern society. But the sight of lawyers making a lot of money “off the top” of everyone else’s struggles to make a living (or at least the preception that this is what many of them do) does clearly stick in people’s craw.

    For an obvious recent example see Nick Freeman, aka “Mr Loophole”, the lawyer beloved of all celebs facing speeding bans or other driving convictions.

    www.guardian.co.uk/transport/Story/0,,1695965,00.html

  44. ed26h said,

    October 31, 2006 at 5:52 pm

    Fallacy Files posted about this yesterday.

  45. Andrew Clegg said,

    October 31, 2006 at 6:58 pm

    Dr Aust. — funny you should mention Nick Freeman — he’s just been arrested on suspicion of conspiracy to pervert the course of justice!

    news.bbc.co.uk/1/hi/england/manchester/6100970.stm

    Andrew.

  46. kay said,

    October 31, 2006 at 7:11 pm

    I suspect when Ben used the phrase “illiterrate tabloid readers” he was not being inherently contradictory but referring to the abuse metered out to some paediatritions as certain members of the tabloid readership did not know the difference between a paediatrtion and a paodophile.

  47. kay said,

    October 31, 2006 at 7:13 pm

    yes, I know it’s spelt with an e

  48. kim said,

    October 31, 2006 at 9:13 pm

    I think the single incident that involved a paediatrician being hounded by tabloid readers has been blown out of proportion, hasn’t it?

  49. pv said,

    October 31, 2006 at 10:06 pm

    “I think the single incident that involved a paediatrician being hounded by tabloid readers has been blown out of proportion, hasn’t it?”

    No, it hasn’t. Not for the paediatrician concerned, not as far as the intelligence of the NoTW readers is concerned and not in respect of the idiotic, fake moral outrage of the tabloid press in general.

  50. tjb said,

    November 1, 2006 at 2:09 pm

    The irony is that the retelling of this story has itself become an exercise in tabloid style exaggeration, though the original incident was doubtless extremely unpleasant for the victim.

    At least if

    news.bbc.co.uk/1/hi/magazine/4719364.stm

    is to be believed.

  51. kim said,

    November 1, 2006 at 5:50 pm

    There was one incident. It was six years ago. We don’t even know that the people concerned actually confused paediatrician and paedophile: that was the best guess of the paediatrician concerned. For all we know it may have been a case of mistaken identity. (See news.bbc.co.uk/1/hi/wales/901723.stm for more details.)

    But then, the incident gives lots of people the opportunity to feel smug and morally superior to tabloid readers, and I guess that’s all that matters.

  52. doctormonkey said,

    November 1, 2006 at 7:18 pm

    going all the way back to #34 and #35…

    not only have lawyers maintained their self-regulation but one of the cornerstones of the attacks on the medical profession’s professionalism has been from the (lawyer) at the head of the Shipman Inquiry (Dame Janet Smith) who appears to have gone on a self-appointed, government funded witch hunt/jihad. the thought that occurs is sort your own mess out legal-types!

    in terms of expert witnesses, particularly if you pay, i think you can find an “expert” who would say almost anything: historians who deny the Holocaust, scientists who deny evolution etc

    and on a more topical note, it is nice to see the loophole-lawyer (Nick Freeman) get nicked, even if he hasn’t done anything, just on as a point of principle (and well done the psychic Dr Aust)

    #43 Dr Aust comments that lawyers get paid irrespective of the outcome of a case but for their time – so do doctors, we are not ill, we do not care (personally) for the patient, we attend because we are paid to. i have heard stories of medicine from China where doctors were paid only when patients got better but this may be apocryphal (certainly scary for palliative care doctors…)

  53. Dr Aust said,

    November 1, 2006 at 7:49 pm

    Hi Dr M.

    I think Drs being paid for time (cf lawyers) is a fair analogy with PRIVATE medicine, where the Dr is billing separately for every consult. Then it clearly does resemble the lawyers’ set-up, as the patient (or insurance) is charged for every last bit, more service (no matter how small), more money. For instance, when I had a minor op privately a few yrs back the general surgeon’s fee for the initial

  54. Dr Aust said,

    November 1, 2006 at 7:58 pm

    Oops… dunno what happened to the rest of that post…

    …fee for initial (well under 10 min) consultation was £ 130, fee for a look-see a week after minor op to chek healing £ 70 for under 2 min. All plus the operation cost.

    Being a 9-5 salaried lifer is a bit different.

    What I was really getting at was that, in e.g. a negligence case, only the lawyers were being paid for every service delivered – per hr worked, per letter sent etc. More tiem into it, more pay. The Dr being sued and anyone else making witness statements would be just adding it to their regular work.

    For instance, last time Mrs Aust was involved (giving a statement) in a medical negligence case she spent a good 10 hrs reviewing notes and documents, clarifying and explaining terms and matters of medicine (for the lawyers), making a statement, correcting statement etc etc. All at home, all for no payment, she hadn’t worked for the Trust in the case for several years. All done as “professional courtesy”. Would have been even more time had the case gone to court.

  55. Dr Aust said,

    November 1, 2006 at 8:03 pm

    A further thought:

    Surely the people MOST analogous to lawyers in terms of their “hired gun” role vis-a-vis most of us are those 90s-and-noughties uber-successes the (management) consultants?

    External to the organisation, charge by the hour, large rates, everything is chargeable (to the last lunch/paperclip/taxi), make you spend your time explaining your job to them (with the meter running) so that they can tell you (based on their larger brain power and “blank sheet of paper” approach) how you SHOULD be doing it etc etc.

  56. doctormonkey said,

    November 1, 2006 at 8:16 pm

    Dr Aust:

    just had an interesting evening with a small group of other intelligent West London private school educated, masters graduates about management consultancy as many of our friends are such creatures. on balance they are about as bad as the lawyers from our year at school too. i am the only medic in the group (the others all took longer over their courses or gap years or both).

    i agree that the analogy to medicine is more that of private medicine than NHS although could the NHS be compared to the CPS (agghhh God NOOOOoooooo……) or the american style state defenders? buying doctor or lawyer time collectively. another group that occurs are the Treasury Solicitors who are the civil service/government lawyers.

    i do think that it is disgusting the amount of effort that people have to put in when there are cases, such as the one you mention Frau Doctor Aust beinginvolved in, when they are not paid for it – curious what would happen if a doctor attempted to bill the lawyers or their clients directly? i suppose the question would be which to bill but you could always bill both if it is a statement (both will use it) or the ones who ask for an opinion (as only one will use it) and bill by the hour (1 hour minimum).

    i may start to look at law conversion degrees… self regulation and seemingly a license to print money although would lose some benefits like ability to stab people (with a needle) with less chance of police coming after me!

  57. Dr Aust said,

    November 1, 2006 at 10:29 pm

    Yes, converting to become a lawyer is something I hear a lot of my medical acquaintances joke about, although I have only known one doctor who actually did it. He was a surgeon, BTW, so for him to jump ship the potential financial rewards of lawyering must have looked seriously Big League (slight joke).

    Even Mrs Dr A has muttered occasionally about doing the law conversion thing, with the usual bitter gags about reading the case notes just the same as now but being able to bill the reading time at £ 150 / hr.

    A more serious point about this is, I guess, the one about the death of the old “professionalism” which these sorts of discussions raise. This applies to many many public sector jobs – medicine, teaching, academia, social work etc. People used to feel it was part of the “unspoken contract” to go the extra mile, work 90 min past the shift end or handover, read stuff in the evenings, do out of school clubs, and so on. But with the rise of the centrally-imposed targetting, and the nitpicking clipboard-toting oversight bureaucracy that goes with it, people increasingly take the view that if you want extra hours done you can !*!”ing well pay for them.

  58. doctormonkey said,

    November 1, 2006 at 11:48 pm

    re: professionalism (#57) and slightly off topic

    i think i lost the inclination to “go the extra mile” when working rotas that were borderline illegal or dubious in their “banding” (banding is the supplement paid to account for the length of or anti-social nature of extra hours over a normal working week of Monday to Friday, 8-7) and so i felt that if they wanted to abuse me like this then they (they = “management”) would not get extra work out of me if they were avoiding paying me for this time/work

  59. elder_pegasus said,

    November 2, 2006 at 9:49 am

    dragging right back to the original point, I’ve dug out the bmj article on the original decision to strike him off…

    worth noting… “Mary Clark-Glass, chair-woman of the GMC’s fitness to practise panel, told him he had undermined public confidence in doctors who play a pivotal role in the criminal justice system as expert witnesses.” – it seems entirely fair that he was accused of this given that he not only produced the irrelevant and dodgy statistics himself, he seemed to have made no effort to retract them (anyone able to contradict that, please do)

    The article also notes (annoyingly without details or source) “that a cot death is more likely than murder” – if that’s true, there’s the relevant statistic.

    Although the whole notion of convicting or otherwise based on statistical probability seems somewhat incompatable with “beyond reasonable doubt” anyway…..

  60. stever said,

    November 2, 2006 at 9:34 pm

    All very interesting.

    My recolection – no doubt twisted by crap media reporting was that Meadows saw the news story on Tv and approach the police of his own volition saying he was convinced it was mnurder, with no evidence beyond the TV story. i thought that was why he got struck off.

  61. Alvin said,

    November 3, 2006 at 8:26 am

    Ben, thank you for the nice discussion on this topic and your input. Though I agree with you that indeed the should also be shared by the judge, lawyer, jury, and Meadows himself, I do not think that Meadow was the scapegoat in this situation. Sir Roy Meadow was hired as an expert witness to this case. His credibility is based on his expertise in this area and when asked a question in the case, he is expected to give valid information. When he quoted the “1 in 73 million” figure, he is idirectly giving false information to the case and in turn affected the outcome of the case. Because he is an expert int his area and his expertise was relied on heavily for the conviction of Sally Clark, he should hold full resonsibility for his action. Had he not quoted that figure, the outcome of this case could have been different.

  62. petey said,

    November 3, 2006 at 9:22 am

    Ben said “But now that the rare event of two babies dying in one family has occurred, the two explanations – double murder or double SIDS – ”

    There are another 2 scenarios – one murder and one SID, either one being the first event.

  63. Alvin said,

    November 3, 2006 at 9:34 am

    Quote “29 billgibson said:
    October 30, 2006 at 2:03 pm
    My neighbour the forensic pathologist calls expert witnesses “liars for hire”. They aren’t independant, each one is paid by one side to give an opinion.

    ———–

    Though I do see that there is potential for expert witnesses to give biased opinions, one may also say that both sides can get their own expert witness. Moreover, the court could also be hiring its own witness for the case to make sure the information is valid. Being an expert witness also mean that your expertise is your credibility and qualifies you to give your testimony in the court. If one fails to do that or give biased opinions they will be punished legally and loses their credibility as an expert witness – an example would be Sir Roy Meadow.

  64. apothecary said,

    November 3, 2006 at 10:39 am

    Lots of medics/pharms/nurses are innumerate. Big Pharma is another player that makes hay with this – quoting eg relative risk reductions in its marketing. Doing a brief presentation to some SpRs and consultants, pointing out that for any relative risk reduction, the absolute risk reduction depends on the baseline risk (durr!) it was truly frightening how many had never thought about that before.

    But as RS said back at 5, we need to be a lot more Bayesian. At best, that is what a criminal trial should be – lots of small pieces of evidence which, on their own, may not have huge positive or negative likelihood ratios, but put together give us a pretty good negative or positive predictive value. Omitting evidence like the possibility of infection – which would have had a reasonably strong negative likelihood ratio wrt foul play – was IMVHO at least as bad as attempting to quantify a risk far better expressed as “very rare”.

  65. Dr Aust said,

    November 3, 2006 at 3:15 pm

    stever wrote:

    “My recollection – no doubt twisted by crap media reporting was that Meadow saw the news story on Tv and approach the police of his own volition saying he was convinced it was murder, with no evidence beyond the TV story. i thought that was why he got struck off.”

    You’re confusing Roy Meadow with Professor David Southall, who is the paediatrician this story applies to, steve – see:

    news.bbc.co.uk/2/hi/health/3538320.stm

    bmj.bmjjournals.com/cgi/content/extract/329/7462/366-a

    Southall was not struck off, but was reprimanded and had restrictions placed on his work.

  66. RS said,

    November 3, 2006 at 4:50 pm

    “…we need to be a lot more Bayesian. At best, that is what a criminal trial should be”

    Although you want to avoid one of the majore flaws in Bayesian reasoning, the use of arbitrary subjective probabilities, which are particularly open to abuse, as in:
    en.wikipedia.org/wiki/Regina_versus_Denis_John_Adams#Use_of_Bayesian_analysis_in_the_court

  67. Dr Aust said,

    November 3, 2006 at 6:12 pm

    Of course, one can view both Meadow and Southall as cautionary tales; gifted people who did important work but became so wrapped up in their theories that they could not be objective about them, and ultimately were unable to accept that they might ever be mistaken…. a very dangerous frame of mind for an expert witness.

    In Southall’s case he was/is famous for his work using covert video recording in a group of children who had a history of “unexplained life-threatening events” and where the doctors suspected the parents might be responsible. In a celebrated study Southall showed using the video surveillance that in a number of these cases a parent was indeed harming the child.

    pediatrics.aappublications.org/cgi/content/abstract/100/5/735

    The upshot of this work was that no matter how unthinkable it was that parents might intentionally harm their own small children, to the point of suffocating them, it clearly did occur.

    Of course, that it CAN happen, and sometimes does, doesn’t tell you HOW LIKELY it is to be occurring. Southall and his co-workers made this point very explicitly at the time, although you might conclude later events showed he lost sight of this.

    So we are back to the begining with the questions “What are the real relevant statistics?” and “Who should be capable of working out how they are derived?”

    PS It’s amazing what you can find on the net – the full High Court Judgement on Professor Southall vis-a-vis the Clark case is at:

    www.bailii.org/ew/cases/EWHC/Admin/2005/579.html

  68. doctormonkey said,

    November 4, 2006 at 5:05 pm

    #67 – wow Dr Aust, a magnificent link to the full High Court Judgement, I have just taken the time to read it in full and feel that it is definitely worth reading.

    it has changed my understanding of the role of the GMC and such professional bodies in general which as a member of the medical register is quite important!

  69. Robert Carnegie said,

    November 5, 2006 at 2:31 pm

    Message 62, Petey – Natural death of a child and child murder are both rare in the English middle class, both are somewhat liable to be repeated for siblings for various reasons, and they’re probably more-or-less independent. So it’s more likely – I don’t want to try to say -how- much more – that two child deaths in a family are both due to the same one of these causes, than that they are one of each. That’s as a probability exercise – which is not necessarily directly convertible to the legal principle of “beyond reasonable doubt”. Back to the lottery, if I buy a ticket is it beyond reasonable doubt that I haven’t won the jackpot, and, that being the case, why did I buy the ticket… And in a murder case or a lottery, in fact it either was or wasn’t. (Leaving aside that “murder” gets slippery when you claim “diminished responsibility”, but I suppose we hear that claimed much more than it’s allowed.)

    And the disgrace of Professor Sir Roy Meadows does not mean that Sally Clark was not charged with a crime that she had committed. For that matter, I gather that Dr WIlliams’s final opinion was that one of the Clark children was shaken to death and one was smothered, the former being the case with the mishandled evidence of infection. That view – for whatever it’s worth – doesn’t support a similar genetic or accidental cause for both deaths,

    As for future inquiries and which set of other cases should be used for any comparison… I think the set of parents with multiple infant deaths will include multiple child murderers as well as multiple natural death victims, so you couldn’t tell the difference, whereas the set of families with one death will proportionately include fewer murderers – I assume that overall there are fewer murderers – and there wouldn’t be much difference between parents who have had one child, and parents who, due to a death, have had one child at a time. But I expect families of more than one child at one time to have measurably different outcomes. Of course that will partly because, purely statistically, these children were lucky enough to be born without either a disease or a murderous parent that would do them in before the second child arrived.

    I also think that parents are not from their own birth either evil people who will inevitably murder their child or normal people who will certainly not do so. Caring for an infant is incredibly stressful, women typically also have a hormone roller-coaster to deal with, and your sanity is under terrible pressure. When and whether this should or should not be a valid defence against a charge of harming a child, I consider to be lower on the agenda than arranging as much support as possible for the family so that these tragedies don’t happen.

  70. apothecary said,

    November 5, 2006 at 6:14 pm

    >>it has changed my understanding of the role of the GMC and such professional bodies in general which as a member of the medical register is quite important!

    Must just share this www.blacktriangle.org/blog/?p=1485 re my own professional regulatory body.

  71. apothecary said,

    November 6, 2006 at 4:39 pm

    re 70. Just re-reading that, I want to make clear that black triangle is not my blog, I am not Antony Cox and was never intending that anyone would think I was. I’m 99% certain no-one would have made that misinterpretation, but just to be certain…

  72. Dr Aust said,

    November 6, 2006 at 7:00 pm

    Re post 69:

    Interesting points about parents, Robert.

    if you take Southall’s Pediatrics paper at face value, the majority of the parents who his video surveillance found physically harming children were diagnosed (subsequently) by psychiatrists as having “personality disorders”, although this is a pretty catch-all term (includes a wide range of things, and of varying degrees of severity). From the histories given it seems clear many of these parents themselves had grim childhood personal histories, perhaps not unexpectedly.

    I do agree with you generally about the strain that having kids put on everyone, though. Given the pressures I am never that surprised that some parents do hit children. The tragedy is that most parents who don’t cope well could probably be helped effectively – when one watches the TV shows like “Little Angels” and “House of Tiny Terrors” that (child psychologist) Tania Byron does, the results do seem to be quite startling, and show what a bit of good advice and support can do for parents who often appear to be at their wits’ end. As a society I think we in the UK are not very good at supporting parents, and the ones that most need the support probably are the hardest to reach, for all sorts of reasons including social exclusion.

    Dealing with the kinds of cases described in some of the published papers on parents harming kids really must be a truly awful job. I have one friend who is a senior child protection social worker, and another who is a community pediatrician, and I wouldn’t do either of their jobs for any money there is.

  73. Dr Aust said,

    November 6, 2006 at 7:10 pm

    Re post 69:

    Interesting points about parents, Robert.

    if you take Southall’s Pediatrics paper at face value, the majority of the parents who his video surveillance found physically harming children were diagnosed (subsequently) by psychiatrists as having “personality disorders”, although this is a pretty catch-all term (includes a wide range of things, and of varying degrees of severity). From the histories given it seems clear many of these parents themselves had grim childhood personal histories, perhaps not unexpectedly.

    Of course, the kind of serious premeditated life-threatening harm his paper was discussing is a long way from (e.g.) a mum-at-end-of-tether slapping a screaming two yr old in a flash of anger after four sleepless nights. The abuse in the Southall paper’s cases was implied to be repeated, was rather deliberate, and was not associated with any triggering event (like screaming).

    I do agree with you generally about the strain that having kids put on everyone, though. Given the pressures I am never that surprised that some parents do hit children. The tragedy is that most parents who don’t cope well could probably be helped effectively – when one watches the TV shows like “Little Angels” and “House of Tiny Terrors” that (child psychologist) Tania Byron does, the results do seem to be quite startling, and show what a bit of sensible advice and support can do for parents who often appear to be at their wits’ end. As a society I think we in the UK are not very good at supporting parents, and the ones that most need the support probably are the hardest to reach, for all sorts of reasons including social exclusion.

    Dealing with the kinds of cases described in some of the published stuff on parents harming kids really must be a truly awful job. I have one friend who is a senior child protection social worker, and another who is a community pediatrician, and I wouldn’t do either of their jobs for any money there is.

  74. Dr Aust said,

    November 6, 2006 at 7:13 pm

    PS Oops – sorry, two versions of the same post there, blame uploading problems. If anyone is in charge you can delete # 72.

  75. doctormonkey said,

    November 6, 2006 at 8:30 pm

    clearly no one is in charge – all hail discordia, long may chaos rule (if #72 is deleted, delete this too!)

  76. Skindoc said,

    November 10, 2006 at 12:53 am

    Ben,I wish I’d joined this discussion a few days ago but it has been a salutary lesson that my distaste for the Left wing politics of the Guardian has deprived me of the opinion of someone who is clearly on the side of the truth rather than that of expediency. The Truth is not what the Courts of this country are searching for but rather Justice, and there is something to be said for that. The Court has already said that it would be better to allow a child murderer to go free rather than risk the conviction of a loving parent for the murder of her child.Roy Meadow was one of the first to realise than the mother, who was his natural ally in the fight for her child’s life, might be the agent of his distress.He has been hounded, vilified and humiliated by scientifically and medically illiterate journalists and by the vilest of the legal profession who more properly deserve the title of ‘professional liers’ than do the medical experts alluded to by an earlier commment.BBC journalists transposed words blatently to further their lies and even today, with the latest Appeal by the GMC, reputable jounalists repeat the lie that Meadow was responsible for the incarceration of Sally Clark for the murder of her babies, Christopher and Harry, when, as you correctly say, it was the failure of a pathologist to put before the court pathological results which he thought were irrelevent but were not within his discretion to withhold.That these results could then be exploited to suggest that a baby who is feeding happily whilst sitting in a bouncy chair should, in the space of a few minutes whilst one parent was out of the room, succumb to an infection whose very nature is its slow malevolence, a little child with muliple injuries including bleeding into the brain and spine ,is to realise that our system, whatever else it does, does not speak for the baby whose last minutes might not have been spent in the tender care of its mother but in dreadful pain at her hands.Sally Clark was convicted of murder on the evidence before the jury of damage to both her dead children.The evidence of Meadow, the infamous evidence of Meadow, the evidence used by the egregious lawyers to attempt the liberation of any convicted of murder to whom could be linked his name was of no importance, because, as you have already said, it was irrelevent to the case and was only introduced because the Defence were assumed, erroneouly, to be basing their case on the supposition that the deaths were SIDS.Any competent Defence team would counter with an immediate question as to the likehood of double murder or even have introduced their own expert but they didn’t because they had decided that the deaths could not possibly be so classified.They were not Meadow’s statistics but the results of the statistician’s analysis of the nationwide survey into cot deaths over many years.What these figures show is that if you are a middle class affluent family who don’t smoke, and are of a certain age, then your chance of having two cot deaths is very very rare indeed.I haven’t been able to find any such cases in the last decade and more, so we are getting to the time when Meadow’s(the survey’s) figures may well be more accurate than his detractors might wish .He certainly was inept with his colouful metaphors to exlain probability to the jury but to have struck him off was an act of consumate cruelty made by a Fitness to Practise Committee who I ,and many of my colleagues in Medicine, thought deeply shameful.I asked that Mrs Clark-Glass and the others castigated for their incompetence by Judge Collins in Meadow’s appeal should resign from any futher practise that might allow then to sit in judgement of their betters.They declined to do so.We still have reports that Sally Clark was’wrongfully’ found guilty when she was quite properly found guilty by a jury on the evidence of the circumstances of the deaths of the children and the nature of their injuries.Her second Appeal was allowed because of missing pathology reports which were used as the basis of a medically preposterous suggestion that a healthy baby up and died from an infection in the space of a few minutes.The allowing of an Appeal does not carry with it a presumption of innocence. Children are killed by their parents.They always have been and they always will be.Someone has to speak on their behalf . Meadow did and look where it got him.

  77. biker said,

    November 12, 2006 at 6:24 pm

    Wow! All that without drawing breath! And, may I say, totally missing the point. (#76)

    My twopenneth, which I’ve thought since first following the trial, is that Prof Meadows is guilty of serious misconduct and should be struck off..
    Whether his “evidence” was crucial or irrelevant is not the point. Neither is the accussed’s guilt or otherwise. Nor the incompetence of the defence in not questioning the testimony.
    He was in a position of authority, intended to be trusted by the jury as such. He had a duty to be sure he knew what he was talking about, yet he clearly did not. Forget even the prosecutor fallacy; what he asserted was clearly wrong to anyone with an O level in maths. If he did not understand basic statistics, as he clearly did not, then he had no right to quote them, indeed he has a duty NOT to. In short, he strayed outside his area of expertise, but allowed others to believe he had not done so, whilst giving potentially crucial testimony. THAT is what is unforgivable.
    The blatant error which was obvious to me from the start is that, in the real world, outside theoretical coin tosses etc, the fact that someting has occurred once, can strongly influence the chance of it happening again, (whether because of genetic factors, environmental causes, a child murderer living next door, etc ). Prof Meadows has to assume SIDS is a totally random event in order to ignore these factors, in order to draw his conclusions. (Unless we now know definately, irrefutable and without exception, the cause of SIDS. And unless you doctors are keeping it to yourselves, I don’t think we do, do we?)
    If the statistic was supplied by a statistician, then it is surely his role as an expert witness, to factor in the real world to the analysis, not to ignore it. This is a schoolboy error and is frankly, inexcusable.

    (I should add that everything I know about the case comes from news reports, so if I myself am talking B*****s about the detail, I stand to be corrected)

    BTW, fascinating original article. The “Prosecutors Fallacy” had never occurred to me before. (Unless I’ve just described it in a different way above. But I don’t think I have…)
    Keep up the good work, Ben. I’m right behind you all the way, even if this – my first – posting is actually disagreeing with you about the scapegoating aspect. But then, I’m not a doctor :-)

  78. Dr Aust said,

    November 14, 2006 at 10:00 pm

    If anyone is not completely fed up with this subject there is what seems to me to be a a mostly sensible account covering Roy Meadow and his expert witness work, including the Clark case, on wikipedia:

    en.wikipedia.org/wiki/Roy_Meadow

    There is also a press release issued after Sally Clark’s first (failed) appeal trial by the Royal Statistical Society, commenting on evidence consisting largely or entirely of statistics:

    www.rss.org.uk/docs/Royal%20Statistical%20Society.doc

    Finally, for a recent medical take (not too hard to read) on the whole issue of child protection, which sheds light on why many paediatricians have some sympathy with Roy Meadow, see the review in the Journal of the Royal Society of Medicine at:

    www.jrsm.org/cgi/content/full/99/1/6

  79. Steiny said,

    November 18, 2006 at 9:02 pm

    Hi Ben,

    I had such a good time chatting last night that I thought I’d pay you the highest form of compliment I am capable of, namely by reaching down from my ivory tower to attack you for promoting the sort of myth you so rightly scorn when done by others.

    The crime of which you are accused is in the very first line of the above article:

    “There once was a time when your biggest worry, as a paediatrician, was being lynched by a herd of illiterate tabloid readers”

    A good introductory gag, no doubt. Made me smile, in fact. But it is a gag based on a story which has done a good bit to fuel the idea the that once someone is accused of pedophilia the average British community will always hound them to their dooms, no matter how absurd or false the accusation. One gold star for a good choice of investigative topic for Brendan O’Neill, one trip to stand in the naughty rumour circulating corner for Ben :)

    news.bbc.co.uk/2/hi/uk_news/magazine/4719364.stm

    ta ta,

    Tom

  80. Ben Goldacre said,

    November 18, 2006 at 10:23 pm

    fly moves steinberg. not only do i know brendan’s article, i half-heartedly tried to track down yvette coete, the doctor, for an interview, through a mate on a paeds rotation out west, sadly without success. she was a paeds SpR, i think, not a consultant, if i can lower myself even further into glorious pedantry and gently chide brendan in turn. so guilty as charged, i propagated it knowingly, as an in joke with myself, and for that reason i specifically said it was a worry, not a fact, because of course spreading fear is our business.

  81. Geoff_S said,

    November 24, 2006 at 11:06 pm

    There’s an interesting lecture by Peter Donelly on the Technology Entertainment design (TED) site in which he gives a very good explanation of statistical errors in the prosecution’s arguments in the Sally Clarke SIDS case.

    Look here:
    www.ted.com/tedtalks/index.cfm?flashEnabled=1

    There’s lots of other interesting stuff there too.

    Geoff

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