Focus on Alternative and Complementary Therapies
www.pharmpress.com/fact
Focus Alternat Complement Ther©2005 Pharmaceutical Press
Focus Altern Complement Ther 2007; 12: 239–40
The days when sceptics could claim that CAM is a data-free zone have long gone. I estimate that about 5000 clinical trials have been published to date in this area. Of course, their findings are not always positive – and this seems to create problems.
Take homoeopathy, for instance. About 200 clinical trials are now available. The totality of the reliable trial data does not demonstrate that homoeopathy has effects beyond placebo.1,2 For CAM practitioners, such ‘negative’ evidence presents a problem and so some have adopted a range of strategies to deal with it.
The most obvious solution is to not accept scientific evidence at all – some practitioners insist that CAM cannot be researched with the methodologies available to date.3 But that form of denial is now becoming more and more difficult. Homoeopaths, for instance, do regularly embrace RCTs – as long as their results suggest that homoeopathy is effective. Therefore methodological or ethical arguments against the RCT collapse like a house of cards.
A better counter-attack might be to agree that evidence is alright but it has to be the right type. Clinical experience and hundreds of years of experience supersede a few RCTs.3 Much of CAM has been field tested on millions of people for thousands of years. Does this knowledge not carry more weight than a few clinical trials on only a few hundred patients? This line of reasoning convinces many – but unfortunately only those who had been CAM enthusiasts in the first place. Hundreds of years of experience are, of course, important. They help us formulate a hypothesis (e.g. treatment x is effective for condition y) but they do not constitute proof of that hypothesis. Proof can only come from scientific testing. The history of medicine has demonstrated this over and over again. Bloodletting, for instance, was used for thousands of years but proper scientific investigations were required to show that it is ineffective for most conditions and frequently outright dangerous.
Another option is to simply ignore the evidence. Few CAM practitioners seem to have any interest in evidence at all.3 Most believe and practice what they have been taught and claim to be guided by their experience. Critical thinking is not what they are trained in, and no one seems to demand this skill from them. Come what may, evidence does not concern them. This strategy has been adopted by many CAM practitioners. For doctors, it is not a viable option: ignoring best evidence is no longer considered ethical. Doctors can even get struck off the register if they do. The time will come, I predict, when CAM practitioners will have to abide by similar rules.
However evidence cuts both ways – for many forms of CAM it is ‘positive’. For instance, Hypericum perforatum (St John’s wort) is effective for treating mild to moderate depression, Crataegus monogyna (hawthorn) extracts improve the signs and symptoms of heart failure, Gingko biloba (gingko) is effective for intermittent claudication, and acupuncture eases the pain of osteoarthritis.4 Why then do so few doctors prescribe these treatments? Again evidence does not seem to translate into clinical practice, and again this causes problems.
A common argument of the CAM opponent is that the evidence is flawed. True, not all CAM research is pristine but, in comparison to research in mainstream medicine it is acceptable – and often even better.5,6
Another popular (but not very original) strategy is to simply take no notice of the evidence. What I do not know does not exist. But again, this is hardly ethical. So far the UK General Medical Council has only penalised doctors who ignore mainstream evidence. Will the time come when doctors are struck off for ignoring ‘positive’ CAM evidence?
Perhaps it would be a step in the right direction to abandon the terminology of ‘positive’ and ‘negative’ evidence altogether. If we think about it clearly, it does not make much sense. If research demonstrates tomorrow that shark cartilage, for instance, does not cure cancer, is this really ‘negative’? It would mean that sharks are no longer hunted for their cartilage, more patients spend their money on treatments that actually work, and no more false hopes are being raised. In my view, this cannot be called ‘negative’. Evidence should therefore not be cat-egorised as ‘positive’ or ‘negative’ but as convincing or unconvincing. Convincing evidence means progress and that, in my view, can hardly be negative.
Problems with evidence exist on both sides. We all tend to like evidence and scientific rigour as long as it confirms our own beliefs. But let us be quite clear about this: such use of evidence is actually an abuse of evidence. To a large degree, evidence is about changing people’s minds. If not, we are using it like a drunken man uses a lamp post: for support rather than for enlightenment.
