Whenever I give a public lecture about homeopathy, I explain what it is, briefly go in to its history, explain what its assumptions are, and what the evidence tells us about its efficacy and safety. When I am finished, there usually is a discussion with the audience. This is the part I like best; in fact, it is the main reason why I made the effort to do the lecture in the first place.
The questions vary, of course, but you can bet your last shirt that someone asks: “We know it works for animals; animals cannot experience a placebo-response, and therefore your claim that homeopathy relies on nothing but the placebo-effect must be wrong!” At this stage I often despair a little, I must admit. Not because the question is too daft, but because I did address it during my lecture. Thus I feel that I have failed to get the right message across – I despair with my obviously poor skills of giving an informative lecture!
Yet I need to answer the above question, of course. So I reiterate that the perceived effectiveness of homeopathy relies not just on the placebo-effect but also on phenomena such as regression towards the mean, natural history of the condition etc. I also usually mention that it is erroneous to assume that animals cannot benefit from placebo-effects; they can be conditioned, and pets can react to the expectations of their owners.
Finally, I need to mention the veterinary clinical evidence which – just like in the case of human patients – fails to show that homeopathic remedies are better than placebos for treating animals. Until recently, this was not an easy task because no systematic review of randomised placebo-controlled trials (RCTs) of veterinary homeopathy was available. Now, I am happy to announce, this situation has changed.
Using Cochrane methods, a brand-new review aimed to assess risk of bias and to quantify the effect size of homeopathic interventions compared with placebo for each eligible peer-reviewed trial. Judgement in 7 assessment domains enabled a trial’s risk of bias to be designated as low, unclear or high. A trial was judged to comprise reliable evidence, if its risk of bias was low or was unclear in specified domains. A trial was considered to be free of vested interest, if it was not funded by a homeopathic pharmacy.
The 18 RCTs found by the researchers were disparate in nature, representing 4 species and 11 different medical conditions. Reliable evidence, free from vested interest, was identified in only two trials:
- homeopathic Coli had a prophylactic effect on porcine diarrhoea (odds ratio 3.89, 95 per cent confidence interval [CI], 1.19 to 12.68, P=0.02);
- individualised homeopathic treatment did not have a more beneficial effect on bovine mastitis than placebo intervention (standardised mean difference -0.31, 95 per cent CI, -0.97 to 0.34, P=0.35).
The authors conclusions are clear: Mixed findings from the only two placebo-controlled RCTs that had suitably reliable evidence precluded generalisable conclusions about the efficacy of any particular homeopathic medicine or the impact of individualised homeopathic intervention on any given medical condition in animals.
My task when lecturing about homeopathy has thus become a great deal easier. But homeopathy-fans are not best pleased with this new article, I guess. They will try to claim that it was a biased piece of research conducted, most likely, by notorious anti-homeopaths who cannot be trusted. So who are the authors of this new publication?
They are RT Mathie from the British Homeopathic Association and J Clausen from one of Germany’s most pro-homeopathic institution, the ‘Karl und Veronica Carstens-Stiftung’.
DOES ANYONE BELIEVE THAT THIS ARTICLE IS BIASED AGAINST HOMEOPATHY?