Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy

@article{citeulike:1387313, abstract = {SummaryBackground Homoeopathy is widely used, but specific effects of homoeopathic remedies seem implausible. Bias in the conduct and reporting of trials is a possible explanation for positive findings of trials of both homoeopathy and conventional medicine. We analysed trials of homoeopathy and conventional medicine and estimated treatment effects in trials least likely to be affected by bias.Methods Placebo-controlled trials of homoeopathy were identified by a comprehensive literature search, which covered 19 electronic databases, reference lists of relevant papers, and contacts with experts. Trials in conventional medicine matched to homoeopathy trials for disorder and type of outcome were randomly selected from the Cochrane Controlled Trials Register (issue 1, 2003). Data were extracted in duplicate and outcomes coded so that odds ratios below 1 indicated benefit. Trials described as double-blind, with adequate randomisation, were assumed to be of higher methodological quality. Bias effects were examined in funnel plots and meta-regression models.Findings 110 homoeopathy trials and 110 matched conventional-medicine trials were analysed. The median study size was 65 participants (range ten to 1573). 21 homoeopathy trials (19\%) and nine (8\%) conventional-medicine trials were of higher quality. In both groups, smaller trials and those of lower quality showed more beneficial treatment effects than larger and higher-quality trials. When the analysis was restricted to large trials of higher quality, the odds ratio was 0[middle dot]88 (95\% CI 0[middle dot]65-1[middle dot]19) for homoeopathy (eight trials) and 0[middle dot]58 (0[middle dot]39-0[middle dot]85) for conventional medicine (six trials).Interpretation Biases are present in placebo-controlled trials of both homoeopathy and conventional medicine. When account was taken for these biases in the analysis, there was weak evidence for a specific effect of homoeopathic remedies, but strong evidence for specific effects of conventional interventions. This finding is compatible with the notion that the clinical effects of homoeopathy are placebo effects.}, author = {Shang, Aijing and Huwiler-Muntener, Karin and Nartey, Linda and Juni, Peter and Dorig, Stephan and Sterne, Jonathan A. C. and Pewsner, Daniel and Egger, Matthias }, citeulike-article-id = {1387313}, journal = {The Lancet}, keywords = {allopathy, clinical, comparative, comparison, controlled, effect, evidence, homoeopathy, placebo, study, trial}, number = {9487}, pages = {726--732}, posted-at = {2007-06-13 13:44:51}, priority = {4}, title = {Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy}, url = {http://www.sciencedirect.com/science/article/B6T1B-4GYH5HK-12/2/fb0608e5529d47ba873dab96ec58e8f1}, volume = {366} }

TY - JOUR ID - citeulike:1387313 L3 - citeulike-article-id:1387313 TI - Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy JF - The Lancet VL - 366 IS - 9487 SP - 726 EP - 732 N2 - SummaryBackground Homoeopathy is widely used, but specific effects of homoeopathic remedies seem implausible. Bias in the conduct and reporting of trials is a possible explanation for positive findings of trials of both homoeopathy and conventional medicine. We analysed trials of homoeopathy and conventional medicine and estimated treatment effects in trials least likely to be affected by bias.Methods Placebo-controlled trials of homoeopathy were identified by a comprehensive literature search, which covered 19 electronic databases, reference lists of relevant papers, and contacts with experts. Trials in conventional medicine matched to homoeopathy trials for disorder and type of outcome were randomly selected from the Cochrane Controlled Trials Register (issue 1, 2003). Data were extracted in duplicate and outcomes coded so that odds ratios below 1 indicated benefit. Trials described as double-blind, with adequate randomisation, were assumed to be of higher methodological quality. Bias effects were examined in funnel plots and meta-regression models.Findings 110 homoeopathy trials and 110 matched conventional-medicine trials were analysed. The median study size was 65 participants (range ten to 1573). 21 homoeopathy trials (19%) and nine (8%) conventional-medicine trials were of higher quality. In both groups, smaller trials and those of lower quality showed more beneficial treatment effects than larger and higher-quality trials. When the analysis was restricted to large trials of higher quality, the odds ratio was 0[middle dot]88 (95% CI 0[middle dot]65-1[middle dot]19) for homoeopathy (eight trials) and 0[middle dot]58 (0[middle dot]39-0[middle dot]85) for conventional medicine (six trials).Interpretation Biases are present in placebo-controlled trials of both homoeopathy and conventional medicine. When account was taken for these biases in the analysis, there was weak evidence for a specific effect of homoeopathic remedies, but strong evidence for specific effects of conventional interventions. This finding is compatible with the notion that the clinical effects of homoeopathy are placebo effects. KW - allopathy KW - clinical KW - comparative KW - comparison KW - controlled KW - effect KW - evidence KW - homoeopathy KW - placebo KW - study KW - trial AU - Shang, Aijing AU - Huwiler-Muntener, Karin AU - Nartey, Linda AU - Juni, Peter AU - Dorig, Stephan AU - Sterne, Jonathan AU - Pewsner, Daniel AU - Egger, Matthias UR - http://www.sciencedirect.com/science/article/B6T1B-4GYH5HK-12/2/fb0608e5529d47ba873dab96ec58e8f1 ER -