The article published on homeopathy in the
Lancet recently has fundamental flaws, according to Robert Mathie,
Research Development Adviser of the British Homeopathic Association (BHA)
and Faculty of Homeopathy.
What the paper studied:
The authors analysed placebo-controlled trials of homeopathy and conventional
medicine (matched for disorder and type of clinical outcome) published
up to January 2003 (1). 110 homeopathy trials and 110 matched trials
in conventional medicine were included; they were not necessarily peer-reviewed
papers. They were assessed using standard criteria of trial quality (randomisation,
masking, data analysis methods) and by treatment effect using odds ratios
(an odds ratio of less than 1.0 indicating an effect greater than placebo).
The original studies included a wide range of medical conditions; nearly
half the studies comprised research in respiratory tract infections,
pollinosis & asthma, and gynaecology & obstetrics. The homeopathy
trials concerned all forms of the therapy, including classical (individualised)
homeopathy, ‘clinical homeopathy’, complex homeopathy, or
isopathy. The majority of conventional medicine trials investigated specific
pharmaceutical drugs (non-steroidal, anti-allergic, virostatic, or antibiotic).
Treatment approach in each category of trial was either therapeutic or
prophylactic.
What the paper shows:
Viewing the results of the trials overall, there is a broadly similar
positive treatment effect in both homeopathy and conventional medicine.
In both categories of trial, those with fewer patients typically showed
more positive treatment effects than larger trials. This is shown in
the paper’s Figure 2, where trials with the largest standard error
tend to have the lowest odds ratio. The authors do not quote mean odds
ratios for the two groups of trials. 21 homeopathy trials and 9 in conventional
medicine were judged to be of ‘higher quality’. The author’s
key analysis was then restricted to the ‘larger’ 14 of those
trials (8 homeopathy and 6 conventional medicine; none of them cited
specifically); this analysis resulted in a mean odds ratio of 0.88 for
homeopathy trials and 0.58 for conventional medicine trials. There was
thus no longer a convincing positive treatment effect of homeopathy as
compared with that of conventional medicine. The paper’s main conclusion
is that the clinical effects of homeopathy are probably those of placebo.
What the Lancet editor says:
Under the headline ‘The end of homoeopathy’, the journal
editorial states ‘Now doctors need to be bold and honest with
their patients about homoeopathy’s lack of benefit, and with themselves
about the failings of modern medicine to address patients’ needs
for personalised care’.
It adds the comment ‘Surely the time
has passed for selective analyses, biased reports, or further investment
in research to perpetuate the homoeopathy versus allopathy debate’.
Our commentary on this publication:
As the following paragraphs illustrate, the paper has not demonstrated
homeopathy’s lack of benefit.
Regrettably, in publishing and commenting
on this paper, the journal has displayed some of these unwelcome attributes
of selective analysis and biased reporting.
Investment in clinical
research in homeopathy needs to be enhanced, not withheld.
There are a number of concerns in the way the paper approaches homeopathy
trials: for example, its criteria of study quality do not reflect the
homeopathic relevance of the clinical outcome/s measured; in addition,
placebo-controlled design was probably not appropriate in the trials
of individualised homeopathy (2). In other words, standard assessment
criteria are insufficient to gauge ‘high quality’ in homeopathy
trials.
Another fundamental concern is that the paper gives no clue about the
nature of the 14 trials selected for the key analysis: whether they were
mainly therapeutic or prophylactic, for example, and whether the homeopathic
interventions were classical, ‘clinical’ or complex homeopathy,
or isopathy. Knowledge of these would potentially make a great difference
to the inferences that should be drawn. Given the heterogeneity of homeopathy
trials, it seems unlikely that the design and methods of just 8 can be
representative of 110. Nor are we offered proper summary data on the
odds ratios for effectiveness in the two sets of 110 trials overall;
without such information, it is impossible to gauge the impact of having
narrowed the analysis to just 8+6 trials.
There are other bizarre features of this paper. On reading its text,
it seems that only the literature between 1995 and January 2003 was included
in the analysis. This would have built on a previous major meta-analysis
of homeopathy trials (3). However, on examination of the web-table that
lists all the references, it becomes apparent that 62 of the papers analysed
were actually published before 1995. The remaining papers analysed were
published from that year onwards, but some of the main articles during
that time have not been included. Inexplicably too, a substantial number
of the papers reviewed in the previous meta-analysis are absent from
the new one.
The wider view:
Most independent scientific observers would regard this analysis as
inconclusive in its results and opaque in some of its key methods and
reporting. And it has the limitations of any analysis of clinical research
in homeopathy that attempts to group together all homeopathic conventions
of treatment and all medical conditions that have been investigated.
A comprehensive analysis of that type can merely make overall conclusions
and may miss specific areas of therapeutic importance – the authors
themselves highlight (but dismiss) the fact that 8 trials of homeopathy
in upper respiratory tract infections have strongly positive findings
overall. It is for this very reason that we adopted an analysis of the
homeopathic research literature that focused instead on individual clinical
trials and their findings (reference 10 in the ‘Research in Homeopathy’ section
of the British Homeopathic Association's weebsite) (4).
The way forward:
We certainly agree with the Lancet paper’s authors that ‘future
research efforts should focus on … the place of homeopathy in health-care
systems’ and about ‘the failings of modern medicine’.
That should mean concentrating more on conducting trials that compare
homeopathy properly and fairly with standard medical care. There remains
a place for placebo-controlled trials, but these have to considered with
insight and wisdom. These and other trial design issues in homeopathy
should be properly informed by prior clinical observational research
and well-conceived pilot trials. The Lancet publication has done nothing
to inform this important field of research in the constructive or careful
manner that it deserves.
References:
1. Shang A, Huwiler-Müntener K, Nartey L, Jüni P, Dörig
S, Sterne JAC, Pewsner D, Egger M. Are the clinical effects of homeopathy
placebo effects? Comparative study of placebo-controlled trials of homoeopathy
and allopathy. Lancet 2005; 366: 726-32.
2. Weatherley-Jones E., Thompson EA, Thomas KJ. The placebo-controlled
trial as a test of complementary and alternative medicine: observations
from research experience of individualised homeopathic treatment. Homeopathy
2004; 93: 186-9.
3. Linde K, Clausius N, Ramirez G, Melchart D, Eitel F, Hedges LV, Jonas
WB. Are the clinical effects of homeopathy placebo effects? A meta-analysis
of placebo-controlled trials. Lancet 1997; 350: 834-43.
4. Mathie RT. The research evidence base for homeopathy: a fresh assessment
of the literature. Homeopathy 2003; 92: 84-91.
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was first released by The British Homeopathic Association on
7th September 2005. For further information, please
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