Ben Goldacre vs. Homoeopathy. A kind of Magic?

Ben Goldacre, autore della serie Bad Science sul Guardian,  ha pubblicato sul Lancet lo scorso 16 novembre un articolo sull’omeopatia, seguito da un editoriale sul Guardian.

The Lancet – “Benefits and risks of homoeopathy”
November 16th, 2007 by Ben Goldacre
This is a piece I wrote in today’s edition of The Lancet. You can also see this article there in a nice Lancet PDF, along with a “world report” on homeopathy, and the references in pleasantly accessible Crossref format. To be honest, it almost feels silly writing about homeopathy in the Lancet.

“Benefits and risks of homoeopathy”

Five large meta-analyses of homoeopathy trials have been done. All have had the same result: after excluding methodologically inadequate trials and accounting for publication bias, homoeopathy produced no statistically significant benefit over placebo.
[1–5] And yet homoeopathy can still be clinically useful.

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.

Similarly, modern medicine can offer little for conditions such as many types of back pain, stress at work, medically unexplained fatigue, and most common colds. Going through a theatre of medical treatment, and trying every drug in the book, will only elicit side-effects. An inert pill in these circumstances seems a sensible option.

However, just as homoeopathy has unexpected benefits, so it can have unexpected side-effects. The very act of prescribing a pill carries its own risks: medicalisation, reinforcement of counterproductive illness behaviours, and promotion of the idea that a pill is an appropriate response to a social problem, or a modest viral illness. Similarly, when a health-care practitioner of any description prescribes a pill which they know is no more effective than placebo—without disclosing that fact to their patient—then they disregard both informed consent and their patient’s autonomy. Some could argue that this cost is acceptable, but such old-fashioned paternalism can ultimately undermine the doctor–patient relationship.

There are also more concrete harms. A routine feature of homoeopaths’ marketing practices is to denigrate mainstream medicine. One study found that half of all homoeopaths who were approached advised patients against the measles, mumps, and rubella vaccine for their children.[7] A television news investigation found that almost all homoeopaths who were approached recommended ineffective homoeopathic prophylaxis for malaria, undermined medical prophylaxis, and did not even give simple advice on bite prevention.[8] Undermining medicine is a wise commercial decision for homoeopaths, because survey data show that a disappointing experience with mainstream medicine is one of the few features to regularly correlate with a decision to use alternative therapies. But it might not be a responsible choice.

Homoeopaths can undermine public-health campaigns; leave their patients exposed to fatal diseases; and, in the extreme, miss or disregard fatal diagnoses. There have also been cases of patients who died after medically trained homoeopaths advised them to stop medical treatments for serious medical conditions.[9,10]

All these problems have been exacerbated by society’s eagerness to endorse the healing claims of homoeopaths, and by the lack of a culture of critical self-appraisal in alternative medicine. Publication bias in alternative therapy journals is high: in 2000, only 5% of studies published in complementary or alternative health journals were negative.[11] To my knowledge, the
ethical issues of autonomy and placebo have never been discussed. Homoeopaths routinely respond to negative meta-analyses by cherry-picking positive studies. An observational study,[12] which amounts to little more than a customer-satisfaction survey, has been promoted[13] as if it trumps a string of randomised trials.

Homoeopaths can misrepresent scientific evidence freely to an unsuspecting and scientifically illiterate public, but in doing so they undermine the public understanding of what it means to have an evidence base for a treatment. This approach seems particularly egregious when academics are working harder than ever to engage the wider public in a genuine understanding of research,14 and when most good doctors try to educate and involve their patients in the selection of treatment options.

Every criticism I have made could be managed with clear and open discussion of the problems. But homoeopaths have walled themselves off from academic medicine, and critique has been all too often met with avoidance rather than argument. The Society of Homeopaths (in Europe) has even threatened to sue bloggers [15] and the university courses on alternative medicine which I and others have approached have flatly refused to provide basic information, such as what they teach and how.[16] It is hard to think of anything more unhealthy.

To ban homoeopathy would be an over-reaction, as placebos could have a clinical role. However, whether the placebo effect is best harnessed by homoeopaths will remain questionable until these ethical issues and side effects have been addressed.

Ben Goldacre
The Guardian, London EC1R 3ER, UK
ben@badscience.net

I am a medical doctor who is also employed by the media as a commentator on pseudoscience and the sociology of medicine.

1 Kleijnen J, Knipschild P, ter Riet G. Clinical trials of homoeopathy. BMJ 1991;
302: 316–23.

2 Boissel JP, Cucherat M, Haugh M, Gauthier E. Critical literature review on the
effectiveness of homoeopathy: overview of data from homoeopathic
medicine trials. Brussels, Belgium: Homoeopathic Medicine Research Group.
Report to the European Commission. 1996: 195–210.

3 Linde K, Melchart D. Randomized controlled trials of individualized
homeopathy: a state-of-the-art review. J Alter Complement Med 1998;
4: 371–88.

4 Cucherat M, Haugh MC, Gooch M, Boissel JP. Evidence of clinical efficacy of
homeopathy: a meta-analysis of clinical trials. Eur J Clin Pharmacol 2000;
56: 27–33.

5 Shang A, Huwiler-Müntener K, Nartey L, et al. Are the clinical effects of
homoeopathy placebo effects? Comparative study of placebo-controlled
trials of homoeopathy and allopathy. Lancet 2005; 366: 726–32.

6 Hempel S. The medical detective. London, UK: Granta Books, 2006.

7 Schmidt K, Ernst E. Aspects of MMR. BMJ 2002; 325: 597.

8 Jones M. Malaria advice ‘risks lives’. Newsnight, BBC2 July 13, 2006. http://news.
bbc.co.uk/1/hi/programmes/newsnight/5178122.stm (accessed Nov 8, 2007).

9 General Medical Council Fitness To Practise Panel. Dr Marisa Viegas. 2007.
www.gmc-uk.org/concerns/hearings_and_decisions/ftp/20070628_
ftp_panel_viegas.asp (accessed Nov 8, 2007).

10 Sheldon T. Dutch doctor struck off for alternative care of actor dying of cancer.
BMJ 2007; 335: 13.

11 Schmidt K, Pittler M, Ernst E. Bias in alternative medicine is still rife but is
diminishing. BMJ 2001; 323: 1071.

12 Spence DS, Thompson EA, Barron SJ. Homeopathic treatment for
chronic disease: a 6-year, university-hospital outpatient observational
study. J Altern Complement Med 2005; 11: 793–98.

13 Grice E. Keep taking the arsenic. Daily Telegraph Nov 25, 2005.
www.telegraph.co.uk/health/main.jhtml?view=DETAILS&grid=
P8&xml=/health/2005/11/25/hhomeo25.xml (accessed Nov 8, 2007).

14 Evans I, Thornton H, Chalmers I. Testing treatments: better research for better
healthcare. London, UK: British Library, 2006.

15 Goldacre B. Threats, the homeopathic panacea. Guardian Oct 20, 2007.
www.guardian.co.uk/science/2007/oct/20/homeopathy (accessed
Nov 6, 2007).

16 Giles J. Degrees in homeopathy slated as unscientific. Nature 2007;

446: 352–53.