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Evidence-Based Complementary and Alternative Medicine
Volume 2013 (2013), Article ID 612890, 7 pages
Research Article

Are the Effects of Homeopathy Attributable to a Statistical Artefact? A Reanalysis of an Observational Study

1Institute of Social Medicine, Epidemiology, and Health Economics, Charité University Medical Center, 10098 Berlin, Germany
2Institute of Integrative Medicine, Witten/Herdecke University, Gerhard-Kienle-Weg 4, 58313 Herdecke, Germany

Received 4 June 2013; Accepted 7 November 2013

Academic Editor: George Lewith

Copyright © 2013 Rainer Lüdtke et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Cohort studies have reported that patients improve considerably after individualised homeopathic treatment. However, these results may be biased by regression to the mean (RTM). Objective. To evaluate whether the observed changes in previous cohort studies are due to RTM and to estimate RTM adjusted effects. Methods. SF-36 quality-of-life (QoL) data from a German cohort of 2827 chronically diseased adults treated by a homeopath were reanalysed by Mee and Chua’s modified -test. Results. RTM adjusted effects, standardized by the respective standard deviation at baseline, were 0.12 (95% CI: 0.06–0.19, ) in the mental and 0.25 (0.22–0.28, ) in the physical summary score. Small-to-moderate effects were confirmed for the most individual diagnoses in physical, but not in mental component scores. Under the assumption that the true population mean equals the mean of all actually diseased patients, RTM adjusted effects were confirmed for both scores in most diagnoses. Conclusions. Changes in QoL after treatment by a homeopath are small but cannot be explained by RTM alone. As all analyses made conservative assumptions, true RTM adjusted effects are probably larger than presented.