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Ben Goldacre’s March 1st Bad Science piece for the Guardian, Don’t laugh, sugar pills are the future, in which he comments on the latest research to show that SSRIs are not much more effective than placebo in treating depression is, as usual, a bit thin on the ground with the actual science itself, even if his title might turn out to be remarkably prescient. And, wonder of wonders, I even agree wholeheartedly with a substantial amount of his earlier piece on February 27th, based on the same study, A quick fix would stop drug firms bending the truth. But far more interesting is the piece by Clive Cookson in the FT, Is there an ethical way to fine-tune the placebo effect?
Evidence-based medicine is a worthy objective. According to the Oxford-based Centre for Evidence Based Medicine, “Evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.”
The present campaign against homeopathy and other complementary therapies makes extensive use of these aims to justify calls for these therapies’ exclusion from the NHS on the grounds that there is “no evidence” for their efficacy. I’ve gone into the evidence question in relation to homeopathy in other posts. This one looks at the evidence base for biomedical treatment. After all, if biomedical treatment is to be so clearly preferred over the complementary therapies which presently lack the robust evidence base being demanded, then one would assume that biomedical treatments have a clear advantage here.
One would assume wrongly.
A lot of hot air has been expended on homeopathy’s apparent inability to “prove” itself in clinical trials. Many people, many of whom call themselves scientists, seem only to need this fact, plus the therapy’s apparent implausibility, to jump to the conclusion the whole thing is nonsense on stilts, and work themselves up into lathers of righteous indignation about the fact that it continues to be practiced. I’ve gone into this a couple of times in the comments to posts on this blog, but this question really does deserve detailed examination, because the issue is not at all as simple as it might seem.
The presupposition of clinical trials is that there is a stable, locally active cause that is only active in the treatment group, irrespective of blinding and the circumstances of the trial or any changed clinical context as a result of the trial. In plain English, this means that the whole basis of clinical trials is predicated on the assumption that the bulk of the treatment effect resides in the physical substance that’s being trialed. It’s a localist hypothesis, proceeding — in homeopathy’s case — from the following logic:
While musing on the nature of evidence, and what is or is not considered ‘evidence’ in all the various contexts evidence is used, I came across this excellent rapid response in the BMJ back in 2004 by Clifford Miller, “a practising English lawyer, graduate in physics and a sometime examining lecturer on law, standards and ethics (particularly, the law of evidence) to Masters student technologists at the Imperial College of Science Technology and Medicine”.
He writes, in the context of the imputed association between MMR vaccination and the onset of autistic states, on “The Unreliability of Scientific Papers as Evidence”:
“Reliable evidence is that which is authentic, accurate and complete. In short, scientific evidence is incomplete if used for purposes outside the strict confines of science because it fails to take account of evidence of lay witnesses of the facts and is hence only applicable to the narrow and specific confines of scientific enquiry and not the broader ones found in other fields of human endeavour.
So now we have another prominent ‘scientist’ joining the chorus. Sir David King, the government’s chief scientific advisor, speaking to MPs on the innovation, universities and skills select committee about his role, laid into sections of the media (for their “campaigns” against GM foods and the MMR vaccine) and the Department of Health over its decision to allow homeopathic remedies to be licensed by the Medicines and Healthcare Products Regulatory Agency, the public body that licenses drugs.
“How can you have homeopathic medicines labelled by a department which is driven by science?” said King. “There is not one jot of evidence supporting the notion that homeopathic medicines are of any assistance whatsoever.”
Make no mistake, this “not one jot of evidence” is nothing more than a mantra which those continually repeating it seem to hope will eventually become accepted as some sort of “truth” merely through repetition. In no sense does it bear any relation to the actual state of the evidence base for homeopathy. It is, quite simply, a lie.
This is the second paragraph from Ben Goldacre’s recent comment piece Benefits and risks of homeopathy in The Lancet’s November 17 edition.
During the cholera epidemic in the 19th century, death rates at the London Homoeopathic Hospital were three times lower than those at the Middlesex Hospital. (6) The reason for homoeopathy’s success in this epidemic is even more interesting than the placebo effect. At the time, nobody could treat cholera, and while medical treatments such as blood-letting were actively harmful, the homoeopaths’ treatments were at least inert.
(6) Hempel S. The medical detective. London, UK: Granta Books, 2006
Notice how Goldacre doesn’t give us the actual figures. (And this is The Lancet, not the Guardian.) Neither does he clarify that his reasoning is speculation, not established fact. The actual mortality percentages would allow readers to make some kind of sensible judgement about his conjecture that medical treatments exacerbated mortality while homeopathic treatment equated to no treatment at all.
OK. Enough is enough. Everyone’s entitled to their own opinions, but when they start claiming their opinions are ‘scientific’, write comments in learned journals quoting published papers in support of their arguments which don’t actually support their arguments at all, misrepresent statistics and generally twist things so far around their little fingers it defies belief, then if you’re a scientist, a homeopath, both or neither, it’s time to put the record straight.
Dr Ben Goldacre, junior doctor and journalist for the UK Guardian, has been adopting a high profile of late. His attacks on alternative therapies, and homeopathy in particular, have reached such a fever pitch it resembles more of a witch-hunt than a scientific debate. Of course all spindoctors know that if you repeat something often enough, sooner or later people start to believe it, whether it’s true or not. Goldacre’s writings, featuring a persuasive mix of jocular sarcasm, apparent scientific plausibility and fearmongering, would have you believe there’s now scientific consensus from unanimous evidence proving that homeopathy is no more than placebo. It’s one thing to publish that in the popular press, another entirely when it appears in The Lancet.
There is, in fact, no factual basis for these assertions. The evidence Goldacre cites doesn’t back up his claims and the ‘science’ he claims to champion is little more than opinion and spin. Of course I don’t expect you to believe me just because I said so, or even because I include citations (1) of papers published in peer reviewed journals in my footnotes. I’m not even asking you to believe me. I’m asking you to look at the actual scientific proof itself, and to do so with a thorough and critical eye.