Department of Complementary Medicine, School of Postgraduate Medicine and Health Sciences, University of Exeter, 25 Victoria Park Road, Exeter EX2 4NT, UK. E-mail: E.Ernst{at}ex.ac.uk
Linde and colleagues present an assessment of 207 randomized clinical trials (RCT) of complementary/alternative medicine (CAM) which points to relevant methodological weaknesses in the evidence supporting CAM.1 Why is this important?
Complementary/alternative medicine is used by more and more people2 and continues to grow at a rate that sends a shiver down the spine of many scientifically-minded physicians. A US think-tank recently concluded that by 2010 at least two-thirds (of the US population) will be using one or more of the approaches we now consider complementary or alternative.3 Is this the advent of the age of unreason?
As a popular consumer-based movement, CAM is almost entirely opinion-based. We recently evaluated the recommendations of seven leading CAM books for specific medical conditions.4 The results demonstrate vividly the dominance of opinion over evidence. Firstly, the recommendations of these seven authors yielded close to zero consistency. Secondly, treatments were recommended which, according to evidence from reliable RCT, are ineffective, in some cases even contra-indicated. Thirdly, treatments which were of proven effectiveness were not recommended by some of these authors.
Such data suggest that the time is overdue to replace opinion by evidence. Therefore the reminder by Linde and colleagues,1 that much of the CAM evidence lacks methodological rigor, is welcome, timely and important. Most probably it also is generalizable across all areas of CAM. US researchers looked at more than 5000 trials of CAM but only 258 met their inclusion criteria. They concluded that the overall quality of evidence for CAM RCT is poor.5 We evaluated 2938 RCT from the Chinese literature, found major methodological shortcomings, and concluded that the quality of trials of traditional Chinese medicine must be improved urgently.6
While we scientists lament the low average quality of RCT, providers of CAM very often have quite a different agenda and rarely feel the need for scientific scrutiny at all. They often argue that CAM, for a number of reasons, defies the straight jacket of reductionistic science. Most readers of the International Journal of Epidemiology will agree that this attitude must be based on misunderstandings; perhaps the best evidence in support is provided by the fact that Linde1 and others5,6 had few no problems locating RCT. What is true, however, is that scientists are constantly and miserably failing to get their points across to advocates of CAM.
Randomized clinical trials of CAM are often more difficult and methodologically more challenging than RCT of other types of interventions. Due to the nature of most CAM modalities and the conditions they are used for, such RCT often need to be large, of long duration and require expensive therapists' time. In turn, this means that CAM research is expensive and requires high levels of expertise in terms of trial design. The demoralizing facts demonstrate, however, that research funds for CAM are rare as gold-dust7 and the infrastructure or culture for CAM research is largely non-existent. Unless fortunes change dramatically, CAM research has therefore little chance of improving. So, is there no hope at all?
Unsurprisingly the solution to these problems lies in creating sufficient resources for supporting CAM research to a level warranted by its popularity. As very few commercial interests are applicable to CAM, the bulk of this money will have to come from official (e.g. government) funds. It is high time that this message is absorbed into political will. On the one hand, most governments seem to feel that, as long as CAM can be contained within the private sector, it will not draw money from their budgets. On the other hand, politicians permanently feel the need to be popular, and lip service to CAM provides one way of fulfilling this need. But vis-à-vis the abundance of open questions and the growing prevalence of CAM use, lip service no longer sufficesit is time to stop talking and start researching in earnest, with rigour and adequate support. To ignore this challenge is nothing less than to ignore the need of the public.
References
1
Linde K, Jonas WB, Melchart D, Willich S. The methodological quality of randomized controlled trials of homeopathy, herbal medicines and acupuncture. Int J Epidemiol 2001;30:52631.
2 Ernst E. Prevalence of use of complementary/alternative medicine: a systematic review. Bull World Health Organ 2000;78:25257.[ISI][Medline]
3 The Institute of Alternative Futures. The Future of Complementary and Alternative Approaches in US Health Care. 1998 NCMIC Insurance Company.
4 Ernst E, Eisenberg D. Complementary and Alternative MedicineA Desk Top Guide. Mosby, 2001.
5 Bloom BS, Retbi A, Dahan S, Jonsson E. Evaluation of randomized controlled trials on complementary and alternative medicine. Int J Tech Assess Health Care 2000;16:1321.[ISI]
6
Tang J, Zhan S, Ernst E. Review of randomised controlled trials of traditional Chinese medicine. BMJ 1999;319:16061.
7 Ernst E. Funding research into complementary medicine: the situation in Britain. Complement Ther Med 1999;7:25053.[Medline]
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