Two new studies conclude that a review which claimed that homeopathy is
just a placebo, published in The Lancet, was seriously flawed. George
Lewith, Professor of Health Research at Southampton University comments:
‘The review gave no indication of which trials were analysed nor of the
various vital assumptions made about the data. This is not usual
scientific practice. If we presume that homeopathy works for some
conditions but not others, or change the definition of a ‘larger trial’,
the conclusions change. This indicates a fundamental weakness in the
conclusions: they are NOT reliable.’ The background to the ongoing
debate is as follows: In August 2005, The Lancet published an editorial
entitled ‘The End of Homeopathy’, prompted by a review comparing
clinical trials of homeopathy with trials of conventional medicine. The
claim that homeopathic medicines are just placebo was based on 6
clinical trials of conventional medicine and 8 studies of homeopathy but
did not reveal the identity of these trials. The review was criticised
for its opacity as it gave no indication of which trials were analysed
and the various assumptions made about the data. Sufficient detail to
enable a reconstruction was eventually published and two recently
published scientific papers based on such a reconstruction challenge the
Lancet review, showing that:
•
Analysis of all high-quality trials of homeopathy yields a positive
conclusion.
•
The 8 larger higher-quality trials of homeopathy were all for different
conditions; if homeopathy works for some of these but not others the
result changes, implying that it is not placebo.
•
The comparison with conventional medicine was meaningless.
•
Doubts remain about the opaque, unpublished criteria used in the review,
including the definition of ‘higher quality’.
The Lancet review, led by Prof Matthias Egger of the Department of
Social and Preventive Medicine at the University of Berne, started with
110 matched clinical trials of homeopathy and conventional medicine,
reduced these to ‘higher-quality trials’ and then to 8 and 6
respectively ‘larger higher-quality trials’. Based on these 14 studies
the review concluded that there is ‘weak evidence for a specific effect
of homoeopathic remedies, but strong evidence for specific effects of
conventional interventions’. There are a limited number of homeopathic
studies so it is quite possible to interpret these data selectively and
unfavourably, which is what appears to have been done in the Lancet
paper. If we assume that homeopathy does not work for just one condition
(Arnica for post-exercise muscle stiffness), or alter the definition of
‘larger trial’, the results are positive. The comparison with
conventional medicine was meaningless: the original 110 trials were
matched, but matching was lost after they were reduced to 8 and 6. But
the quality of homeopathic trials was better than conventional trials.
This reconstruction casts serious doubts on the review, showing that it
was based on a series of hidden judgments unfavourable to homeopathy. An
open assessment of the current evidence suggests that homeopathy is
probably effective for a number of conditions including allergies, upper
respiratory tract infections and ‘flu, but more research is desperately
needed.
Prof Egger has declined to comment on these findings.
References
Lüdtke R, Rutten ALB. The conclusion on the effectiveness of homeopathy
highly depend on the set of analysed trials. Journal of Clinical
Epidemiology, 2008. doi: 10.1016/j.jclinepi.2008.06.015
Rutten ALB, Stolper CF. The 2005 meta-analysis of homeopathy: analysis
of postpublication data. Homeopathy, 2008. doi:10.1016/j.homp.2008.09.008.
Ends
For further information, please contact: Prof
George Lewith Tel: +44 7970 067884 email:
gl3@soton.ac.uk
Rainer Lüdtke Tel: +49 201 5630516 email:
r.luedtke@carstens-stiftung.de
Dr Lex Rutten Tel: +31 765 227340 email: lexrtn@concepts.nl
