Matthias Egger (University of Berne, Switzerland) and colleagues compared 110 placebo-controlled, randomised trials of homoeopathy with 110 conventional-medicine trials matched for disorder and type of outcome. The clinical topics studied in the trials ranged from respiratory infections to surgery to anaesthesiology. The researchers looked at the treatment effects in smaller, low quality trials and larger trials of higher quality. They found, in both groups, that smaller trials of lower quality showed more beneficial treatment effects than larger and higher-quality trials. However, when the analysis was restricted to large trials of high quality there was no convincing evidence that homoeopathy was superior to placebo, whereas for conventional medicine an important effect remained.
Professor Egger concludes: "Our study powerfully illustrates the interplay and cumulative effect of different sources of bias. We acknowledge that to prove a negative is impossible, but we have shown that the effects seen in placebo-controlled trials of homeopathy are compatible with the placebo-hypothesis."
In an accompanying comment Jan Vandenbroucke (Leiden University Medical Centre, Netherlands) states: "Science is an intrinsically human affair. When new theories are created and new evidence sought, judgement will retain a subjective element. This does not mean that it is impossible to sift out which interpretation is more valuable ...The ultimate proof is that science make progress in changing reality: in allopathic [conventional] medicine by preventing, alleviating, and curing disease ever more effectively."
In an accompanying editorial The Lancet comments: "It is the attitudes of patients and providers that engender alternative-therapy seeking behaviours which create a greater threat to conventional care--and patients' welfare--than do spurious arguments of putative benefits from absurd dilutions...Now doctors need to be bold and honest with their patients about homoeopathy's lack of benefit, and with themselves about the failings of modern medicine to address patients' needs for personalised care."
Contact: Dr Matthias Egger, Department of Social and Preventive Medicine (ISPM), University of Berne, CH-3012 Berne, Switzerland. T) 41-31-631-3501 email@example.com
Comment: Professor Jan P Vandenbroucke MD PhD, Department of Clinical Epidemiology, Leiden University Medical Centre, C9-P, PO Box 9600, 2300 RC Leiden, Netherlands. T) 31-71-526-9111 firstname.lastname@example.org
The Lancet press office on 44-207-424-4949 email@example.com