[Omeo33] Art 0866 - Homeopathy, 2008, 97 (4), 169-177

[Gino Santini]

The 2005 meta-analysis of homeopathy: the importance of post-publication data
A.L.B. Rutten and C.F. Stolper

Background - There is a discrepancy between the outcome of a 
meta-analysis published in 1997 of 89 trials of homeopathy by Linde 
et al and an analysis of 110 trials by Shang et al published in 2005, 
these reached opposite conclusions. Important data were not mentioned 
in Shang et al's paper, but only provided subsequently.
Questions - What was the outcome of Shang et al's predefined 
hypotheses? Were the homeopathic and conventional trials comparable? 
Was subgroup selection justified? The possible role of ineffective 
treatments. Was the conclusion about effect justified? Were essential 
data missing in the original article?
Methods - Analysis of post-publication data. Re-extraction and 
analysis of 21 higher quality trials selected by Shang et al with 
sensitivity analysis for the influence of single indications. 
Analysis of comparability. Sensitivity analysis of influence of 
subjective choices, like quality of single indications and of cut-off 
values for 'larger samples'.
Results - The quality of trials of homeopathy was better than of 
conventional trials. Regarding smaller trials, homeopathy accounted 
for 14 out of 83 and conventional medicine 2 out of 78 good quality 
trials with n < 100. There was selective inclusion of unpublished 
trials only for homeopathy. Quality was assessed differently from 
previous analyses. Selecting subgroups on sample size and quality 
caused incomplete matching of homeopathy and conventional trials. 
Cut-off values for larger trials differed between homeopathy and 
conventional medicine without plausible reason. Sensitivity analyses 
for the influence of heterogeneity and the cut-off value for 'larger 
higher quality studies' were missing. Homeopathy is not effective for 
muscle soreness after long distance running, OR = 1.30 (95% CI 
0.96-1.76). The subset of homeopathy trials on which the conclusion 
was based was heterogeneous, comprising 8 trials on 8 different 
indications, and was not matched on indication with those of 
conventional medicine. Essential data were missing in the original 
paper.
Conclusion - Re-analysis of Shang's post-publication data did not 
support the conclusion that homeopathy is a placebo effect. The 
conclusion that homeopathy is and that conventional is not a placebo 
effect was not based on comparative analysis and not justified 
because of heterogeneity and lack of sensitivity analysis. If we 
confine ourselves to the predefined hypotheses and the part of the 
analysis that is indeed comparative, the conclusion should be that 
quality of homeopathic trials is better than of conventional trials, 
for all trials (p = 0.03) as well as for smaller trials (p = 0.003).

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