Download Lectures on Biostatistics (1971). Corrected and searchable version of Google books edition
Download review of Lectures on Biostatistics (THES, 1973).
Low back pain
Of all types of alternative medicine, acupuncture is the one that has received the most approval from regular medicine. The benefit of that is that it’s been tested more thoroughly than most others. The result is now clear. It doesn’t work. See the evidence in Acupuncture is a theatrical placebo.
This blog has documented many cases of misreported tests of acupuncture, often from people have a financial interests in selling it. Perhaps the most egregious spin came from the University of Exeter. It was published in a normal journal, and endorsed by the journal’s editor, despite showing clearly that acupuncture didn’t even have much placebo effect.
Acupuncture got a boost in 2009 from, of all unlikely sources, the National Institute for Health and Care Excellence (NICE). The judgements of NICE and the benefit / cost ratio of treatments are usually very good. But the guidance group that they assembled to judge treatments for low back pain was atypically incompetent when it came to assessment of evidence. They recommended acupuncture as one option. At the time I posted “NICE falls for Bait and Switch by acupuncturists and chiropractors: it has let down the public and itself“. That was soon followed by two more posts:
NICE fiasco, part 2. Rawlins should withdraw guidance and start again“,
and
“The NICE fiasco, Part 3. Too many vested interests, not enough honesty“.
At the time, NICE was being run by Michael Rawlins, an old friend. No doubt he was unaware of the bad guidance until it was too late and he felt obliged to defend it.
Although the 2008 guidance referred only to low back pain, it gave an opening for acupuncturists to penetrate the NHS. Like all quacks, they are experts at bait and switch. The penetration of quackery was exacerbated by the privatisation of physiotherapy services to organisations like Connect Physical Health which have little regard for evidence, but a good eye for sales. If you think that’s an exaggeration, read "Connect Physical Health sells quackery to NHS".
When David Haslam took over the reins at NICE, I was optimistic that the question would be revisited (it turned out that he was aware of this blog). I was not disappointed. This time the guidance group had much more critical members.
The new draft guidance on low back pain was released on 24 March 2016. The final guidance will not appear until September 2016, but last time the final version didn’t differ much from the draft.
Despite modern imaging methods, it still isn’t possible to pinpoint the precise cause of low back pain (LBP) so diagnoses are lumped together as non-specific low back pain (NSLBP).
The summary guidance is explicit.
“1.2.8 Do not offer acupuncture for managing non-specific low back 7 pain with or without sciatica.”
The evidence is summarised section 13.6 of the main report (page 493).There is a long list of other proposed treatments that are not recommended.
Because low back pain is so common, and so difficult to treat, many treatments have been proposed. Many of them, including acupuncture, have proved to be clutching at straws. It’s to the great credit of the new guidance group that they have resisted that temptation.
Among the other "do not offer" treatments are
- imaging (except in specialist setting)
- belts or corsets
- foot orthotics
- acupuncture
- ultrasound
- TENS or PENS
- opioids (for acute or chronic LBP)
- antidepressants (SSRI and others)
- anticonvulsants
- spinal injections
- spinal fusion for NSLBP (except as part of a randomised controlled trial)
- disc replacement
At first sight, the new guidance looks like an excellent clear-out of the myths that surround the treatment of low back pain.
The positive recommendations that are made are all for things that have modest effects (at best). For example “Consider a group exercise programme”, and “Consider manipulation, mobilisation”. The use of there word “consider”, rather than “offer” seems to be NICE-speak -an implicit suggestion that it doesn’t work very well. My only criticism of the report is that it doesn’t say sufficiently bluntly that non-specific low back pain is largely an unsolved problem. Most of what’s seen is probably a result of that most deceptive phenomenon, regression to the mean.
One pain specialist put it to me thus. “Think of the billions spent on back pain research over the years in order to reach the conclusion that nothing much works – shameful really.” Well perhaps not shameful: it isn’t for want of trying. It’s just a very difficult problem. But pretending that there are solutions doesn’t help anyone.
Follow-up
In July 2008 I wrote an editorial in the New Zealand Medical Journal (NZMJ), at the request of its editor.
The title was Dr Who? deception by chiropractors. It was not very flattering and it resulted in a letter from lawyers representing the New Zealand Chiropractic Association. Luckily the editor of the NZMJ, Frank Frizelle, is a man of principle, and the legal action was averted. It also resulted in some interesting discussions with disillusioned chiropractors that confirmed one’s worst fears. Not to mention revealing the internecine warfare between one chiropractor and another.
This all occurred before the British Chiropractic Association sued Simon Singh for defamation. The strength of the reaction to that foolhardy action now has chiropractors wondering if they can survive at all. The baselessness of most of their claims has been exposed as never before. No wonder they are running scared. The whole basis of their business is imploding.
Needless to say chiropractors were very cross indeed. Then in February 2009 I had a polite email from a New Zealand chiropractor, David Owen, asking for help to find one of the references in the editorial. I’d quoted Preston Long as saying
"Long (2004)7 said “the public should be informed that chiropractic manipulation is the number one reason for people suffering stroke under the age of 45.”
And I’d given the reference as
7. Long PH. Stroke and spinal manipulation. J Quality Health Care. 2004;3:8–10
I’d found the quotation, and the reference, in Ernst’s 2005 article, The value of Chiropractic, but at the time I couldn’t find the Journal of Quality Healthcare. I did find the same article on the web. At least the article had the same title, the same author and the same quotation. But after finding, and reading, the article, I neglected to change the reference from J Quality Health Care to http://skepticreport.com/sr/?p=88. I should have done so and for that I apologise.
When I asked Ernst about the Journal of Quality Healthcare, he couldn’t find his copy of the Journal either, but he and his secretary embarked on a hunt for it, and eventually it was found.
|
It turns out that Journal of Quality Healthcare shut down in 2004, without leaving a trace on the web, or even in the British Library. It was replaced by a different journal, Patient Safety and Quality Healthcare (PSQH) A reprint was obtained from them. It is indeed the same as the web version that I’d read, and it highlighted the quotation in question. The reprint of the original article, which proved so hard to find, can be downloaded here. |
|
The full quotation is this
"Sixty-two clinical neurologists from across Canada, all certified members of the Royal College of Physicians and Surgeons, issued a warning to the Canadian public, which was reported by Brad Stewart, MD. The warning was entitled Canadian Neurologists Warn Against Neck Manipulation. The final conclusion was that endless non-scientific claims are being made as to the uses of neck manipulation(Stewart, 2003). They need to be stopped. The public should be informed that chiropractic manipulation is the number one reason for people suffering stroke under the age of 45."
I have often condemned the practice of citing papers without reading them (it is, of course, distressingly common), so I feel bad about this, though I had in fact read the paper in question in its web version. I’m writing about it because I feel one should be open about mistakes, even small ones.
I’m also writing about it because one small section of the magic medicine community seems to think they have nailed me because of it. David Owen, the New Zealand chiropractor, wrote to the editor of the NZMJ, thus.
|
The quote [in question] is the public should be informed that chiropractic manipulation is the number one reason for people suffering stroke under the age of 45. Long PH. Stroke and Manipulation. J Quality Health Care. 2004:3:8-10 This quote actually comes from the following blog article http://www.skepticreport.com/medicalquackery/strokespinal.htm [DC the URL is now http://skepticreport.com/sr/?p=88] I have attached all my personal communications with Colquhoun. They demonstrate this is not a citation error. Prof Colquhoun believes the origin of the quote doesn’t matter because Long was quoting from a Canadian Neurologists’ report (this is also incorrect). As you can see he fails to provide any evidence at all to support the existance [sic] of the “J Quality Health Care.” Colquhoun ‘s belief that my forwarding this complaint is me “resorting to threats” is the final nail in the coffin. If he had any leg to stand on where is the threat? This may seem pedantic but it surely reflects a serious ethical breach. Is it acceptable to make up a reference to try and slip any unsupported statement into a “scientific” argument and thereby give it some degree of credibility? Incidentally, at the end of the article, conflicts of interest are listed as none. As Colquhoun is a Professor of Pharmacology and much of his research funding no doubt comes from the pharmaceutical industry how can he have no conflict of interest with therapies that do not advocate the use of drugs and compete directly against the billions spent on pain medications each year? If I may quote Colquhoun himself in his defence of his article (Journal of the New Zealand Medical Association, 05-September-2008, Vol 121 No 1281) I’ll admit, though, that perhaps ‘intellect’ is not what’s deficient in this case, but rather honesty. David Owen |
Financial interests
Well, here is a threat: I’m exposed as a shill of Big Pharma. ". . . much of his funding no doubt comes from the pharmaceutical industry". I can’t count how many times this accusation has been thrown at me by advocates of magic medicine. Oddly enough none of them has actually taken the trouble to find out where my research funding has come from. None of them even knows enough about the business to realise the extreme improbability that the Pharmaceutical Industry would be interested in funding basic work on the stochastic properties of single molecules. They fund only clinicians who can help to improve their profits,
The matter of funding is already on record, but I’ll repeat it now. The media ‘nutritional therapist’, Patrick Holford, said, in the British Medical Journal
“I notice that Professor David Colquhoun has so far not felt it relevant to mention his own competing interests and financial involvements with the pharmaceutical industry “
To which my reply was
” Oh dear, Patrick Holford really should check before saying things like “I notice that Professor David Colquhoun has so far not felt it relevant to mention his own competing interests and financial involvements with the pharmaceutical industry”. Unlike Holford, when I said “no competing interests”, I meant it. My research has never been funded by the drug industry, but always by the Medical Research Council or by the Wellcome Trust. Neither have I accepted hospitality or travel to conferences from them. That is because I would never want to run the risk of judgements being clouded by money. The only time I have ever taken money from industry is in the form of modest fees that I got for giving a series of lectures on the basic mathematical principles of drug-receptor interaction, a few years ago.”
I spend a lot of my spare time, and a bit of my own money, in an attempt to bring some sense into the arguments. The alternative medicine gurus make their livings (in some cases large fortunes) out of their wares.
So who has the vested interest?
Does chiropractic actually cause stroke?
As in the case of drugs and diet, it is remarkably difficult to be sure about causality. A patient suffers a vertebral artery dissection shortly after visiting a chiropractor, but did the neck manipulation cause the stroke? Or did it precipitate the stroke in somebody predisposed to one? Or is the timing just coincidence and the stroke would have happened anyway? There has been a lot of discussion about this and a forthcoming analysis will tackle the problem of causality head-on,
My assessment at the moment, for what it’s worth, is that there are some pretty good reasons to suspect that neck manipulation can be dangerous, but it seems that serious damage is rare.
In a sense, it really doesn’t matter much anyway, because it is now apparent that chiropractic is pretty well discredited without having to resort to arguments about rare (though serious) effects. There is real doubt about whether it is even any good for back pain (see Cochrane review), and good reason to think that the very common claims of chiropractors to be able to cure infant colic, asthma and so on are entirely, ahem, bogus. (See also Steven Novella, ebm-first, and innumerable other recent analyses.)
Chiropractic is entirely discredited, whether or not it may occasionally kill people.
Complaint sent to UCL
I had an enquiry about this problem also from my old friend George Lewith. I told him what had happened. Soon after this, a complaint was sent to Tim Perry and Jason Clarke, UCL’s Director and Deputy Director of Academic Services. The letter came not from Lewith or Owen, but from Lionel Milgom. Milgrom is well known in the magic medicine community for writing papers about how homeopathy can be “explained” by quantum entanglement. Unfortunately for him, his papers have been read by some real physicists and they are no more than rather pretentious metaphors. See, for example, Danny Chrastina’s analysis, and shpalman, here. Not to mention Lewis, AP Gaylard and Orac.
|
Dear Mr Perry and Mr Clark, I would like to bring to your attention an editorial (below) that appeared in the most recent issue of the New Zealand Medical Journal. In it, one of your Emeritus Professors, David Colquhoun, is accused of a serious ethical breach, and I quote – “Is it acceptable to make up a reference to try and slip any unsupported statement into a “scientific” argument and thereby give it some degree of credibility?” Professor Colquhoun is well-known for writing extensively and publicly excoriating many forms of complementary and alternative medicine, particularly with regard to the alleged unscientific nature and unethical behaviour of its practitioners. Professor Colquhoun is also a voluble champion for keeping the libel laws out of science. While such activities are doubtlessly in accord with the venerable Benthamite liberal traditions of UCL, I am quite certain hypocrisy is not. And though Professor Colquhoun has owned up to his error, as the NZMJ’s editor implies, it leaves a question mark over his credibility. As custodians of the college’s academic quality therefore, you might care to consider the possible damage to UCL’s reputation of perceived professorial cant; emeritus or otherwise. Yours Sincerely Dr Lionel R Milgrom |
So, as we have seen, the quotation was correct, the reference was correct, and I’d read the article from which it came I made a mistake in citing the original paper rather than the web version of the same paper..
I leave it to the reader to judge whether this constitutes a "serious ethical breach", whether I’d slipped in an "unsupported statement", and whether it constitutes "hypocrisy"
Follow-up
It so happens that no sooner was this posted than there appeared Part 2 of the devastating refutation of Lionel Milgrom’s attempt to defend homeopathy, written by AP Gaylard. Thanks to Mojo (comment #2) for pointing this out.
Peter Dixon is a chiropractor. He is chair of the General Chiropractic Council (GCC). He was also a member of the hotly-disputed NICE low back pain guidance group that endorsed (you guessed it) the use of chiropractic, a decision that has led to enormous criticism of the standards of the National Institute of health and Clinical Excellence (NICE).
As a consequence largely of the decision of the British Chiropractic Association (BCA) to sue Simon Singh for defamation, there has been an unprecedented interest taken in the claims made by chiropractors in general.
Peter Dixon has a problem because something like 600 individual complaints about unjustified health claims have been sent to the GCC. Even when a web site does not claim to be able to benefit things like asthma and colic, a phone call may reveal that claims are made in private (one of the many complaints to the GCC concerns such behaviour by two practices belonging to, ahem, Peter Dixon Associates).
The crucial question is, as always, one of evidence. The BCA claim to have a plethora of evidence for their claims, but they have been strangely reluctant to produce it. In fact evidence is cited on the “Your first visit” page on Dixon’s site.
At the bottom we see “How effective is Chiropractic?”.
That sounds very impressive indeed: . ” . . . patients who received chiropractic treatment improved by 70% more than those given hospital out-patient.”
But hang on. If we look at the paper, Meade et al., 1990 [download reprint], we see that Figure 2 looks like this.
Several things jump out. First, the Oswestry disability index scale runs for 0 to 100, but scores are plotted only from 0 to 35, so the size of the effects are exaggerated. Second, there are no error bars on the points. Third there is essentially no advantage for chiropractic at all when all patients are taken together (top graph). Fourth, and most important, the patients who were followed up for two years (bottom graph) seem to show a slight advantage for chiropractic but on average, the effect is 7 percent (on the 100 point scale, NOT 70 percent as claimed on the web site of Peter Dixon Associates.
What sort of mistake was made?
The abstract of the paper itself says “A benefit of about 7% points on the Oswestry scale was seen at two years.” How did this become “improved by 70% more”?
It could have been simple a typographical error, but that seems unlikely, Who’d boast about a 7% improvement?
Perhaps it is a question of relative versus absolute change. The Figure does not show the actual scores on the 100 point scale, but rather the change in score, relative to a questionnaire given just before starting treatment. If we look at the lower part of the Figure, restricted to those patients who stayed with the trail for 2 years (by this time 28% of the patients had dropped out), we see that there is a reduction in score (improvement) of about 10 points on the 100 point scale with hospital treatment (not a very impressive response). The improvement with those sent to private chiropractic clinics was about seven points bigger. So a change from 10 to 17 is a 70 percent change. What’s wrong with that?
What’s wrong is that it is highly misleading, as relative changes often are. Imagine that the hospital number had been 7 points and the chiropractic number had been 14 (both out of 100). That would mean that both treatments had provided very modest benefits to the patients. Would it then be fair to describe the chiropractic patients as have improved by 100 percent more than the hospital patients, when in fact neither got much benefit? Of course it would not. To present the results in this way would be highly deceptive.
Put another way, a 70% increase in a trivial effect is still pretty trivial.
That isn’t all either. The paper has been analysed in some detail on the ebm-first site. The seven point difference on a 100 point scale, though it may be real, is too small to be ‘clinically significant’ In other words the patient would scarcely notice such a small change. Another problem lies in the nature of the comparison. Patients were, quite properly, allocated at random to chiropractic or to to hospital treatment. BUT the comparion was very from blind. one group was treated in hospital. The other group was sent to private chiropractic clinics. The trivial 7 point difference could easily be as much to do with the thickness of the carpets rather than any effect of spinal manipulation.
What this paper really tells you is that neither treatment is very effective and that there is little to choose between them.
It is really most unfortunate that the chairman of the GCC should show himself to be so careless about evidence at a time when the evidence for the claims of chiropractors is under inspection as never before. It does not add to their case for criticising Simon Singh and it does not add to one’s confidence in the judgement of the NICE guidance group.
Follow-up
The Pain Society revolt. A letter has been sent from several distinguished members of the British Pain Society to its President and Council.
“We, the undersigned, call upon the President of the British Pain Society to issue a statement to NICE and to the press condemning outright the conclusions of the recent UK National Institute for Health and Clinical Excellence (NICE) guidelines . . .”
The sigificance of this letter is that the present president of the British Pain Society is Professor Paul Watson who was a member of the NICE guidance group that produced the recommendations which have engendered such criticism. He was clinical advisor to the guidance group. There is a video of Paul Watson talking about back pain, that seems to me to illustrate very well the problem with the guidance. He says it is a huge problem (everyone knows that) and that something must be done, but he doesn’t say what. There is no admission that, in very many cases, nobody knows what to do. It is exactly this sort of hubris that that makes the NICE report so bad,
One caustic comment on the letter says
“We are led by a physiotherapist! A Professor who cannot even interpret straight forward evidence when it is presented to him on a plate.
Who’s going to be the next BPS President? A Hospital Porter?”