Clinical Trials Show Significant Benefits Of Homeopathy

The clinical research literature in homeopathy is more positive than Ben Goldacre prefers to admit in his article Benefits and risks of homoeopathy, published in The Lancet on 16 November [1]. Goldacre claims 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. However, a more complete and unbiased assessment of the research evidence gives a very different perspective:

Three of the 5 meta-analyses that Goldacre cites did not reach the negative conclusion he implies, while the other 2 reports have limited interpretation. The first paper assessed 105 trials, 81 of them positive [2]. The authors concluded: "the evidence of clinical trials is positive but not sufficient to draw definite conclusions". The reviews for the European Commission concluded that homeopathy was more effective than placebo (P < 0.001) [3,4] though the strength of this evidence is low because of the low methodological quality of the trials (P = 0.082 for the highest quality sub-group of just 5 trials) [4]. The fourth analysis focused on trials of individualised homeopathy only, and thus did not represent the entire research evidence [5]. The most recent review narrowed its analysis to just 8 homeopathy trials compared with 6 in conventional medicine [6]; the negative findings were strongly affected by one particular Arnica trial [7].

Most importantly, Goldacre failed to cite one of the largest meta-analyses, which showed homeopathy can produce significant benefit over placebo. Published in The Lancet 10 years ago, Linde and colleagues analysed 89 trials and found a mean odds ratio of 2.45 (95% confidence interval, 2.052.93), in favour of homeopathy [8]. When considering just those trials of high quality and after correcting for publication bias, the findings actually remained statistically significant. The main conclusion was that the results were not compatible with the hypothesis that the effects of homoeopathy are completely due to placebo. In further analysis, the authors clarified that higher quality trials were less likely to be positive than those of lower quality, though the difference from placebo remained statistically significant until analysis was restricted to just five trials [9]. There was insufficient volume of evidence to enable conclusions to be drawn about the efficacy of homeopathy for any specific medical conditon.

Moreover, Goldacre chooses not to report findings of systematic reviews that did in fact focus on research in particular medical conditions. Seven of 17 such reports to date have been positive for homeopathy: childhood diarrhoea [10]; influenza [11]; post-operative ileus [12]; seasonal allergic rhinitis [13,14,15]; vertigo [16]. Eight of the other 10 reviews were non-conclusive [17-24]; 2 were negative [25,26].