Linde K, Clausius N, Ramirez G, Melchart D, Eitel F, Hedges LV, Jonas WB
Are the clinical effects of homoeopathy placebo effects?: A meta-analysis of placebo-controlled trial
In: Albrecht H, Frühwald M, eds. Jahrbuch der Karl und Veronica Carstens-Stiftung, Band 4 (1997). Essen: kvc; 1998: 161-198.
Although Homoeopathy appears to be scientifically implausible, it is quite popular and is widely used. Our aim was to assess whether the clinical effect reported in randomised controlled trials of homoeopathic remedies is equivalent to that reported for placebo.
Methods
We gathered studies from computerised bibliographies, collaborating researchers, institutions, manufacturers, individual collectors, homoeopathic conference proceedings, and books. We included all languages. Double-blind and/or randomised placebocontrolled trials of clinical conditions were considered. Our review of 186 trials identified 119 that met the inclusion criteria. 89 had adequate data for metaanalysis, and two sets of trial were used to assess reproducibility. Two reviewers assessed study quality with two scales and extracted data for information on clinical condition, homoeopathy type, dilution, 'remedy', population, and outcomes.
Findings
The combined odds ratio for the 89 studies entered into the main meta-analysis was 2 45 (95% CI 2.05, 2.93) in favour of homoeopathy. The odds ratio for the 26 good-quality studies was 1.66 (1.33, 2.08), and that corrected for publication bias was 1.78 (1.03, 3.10). Four studies on the effects of a single remedy on seasonal allergies had a pooled odds ratio for ocular symptoms at 4 weeks of 2.03 (1.51, 2.74). Five studies on postoperative ileus had a pooled mean effect-size-difference of -0.22 standard deviations (95% CI -0.36, -0.09) for flatus, and 0.18 SDs (-0.33, -0.03) for stool (both p<0.05).
Interpretation
The results of our meta-analysis are not compatible with the hypothesis that the clinical effects of homoeopathy are completely due to placebo. However, we found insufficient evidence from these studies that homoeopathy is clearly efficacious for any single clinical condition. Further research on homoeopathy is warranted provided it is rigorous and systematic.
Metaanalysis of Clinical Studies on Homeopathy [ Details ]