Supplementary memorandum submitted by
Professor Edzard Ernst
Following my oral evidence to the committee
on Wednesday 25th November 2009 and having read the written evidence
published that day, I am submitting this supplementary memo on
the references made to systematic reviews.
The memorandum submitted by The British Homeopathic
Association (BHA) contains a section on "systematic reviews
of randomised controlled trials" which requires clarification,
particularly as numerous other submissions (e.g. those by Dr Lionel
R Milgrom, Prof H Walach, Prof G Lewith, Dr Sara Eames, Society
of Homeopaths, Complementary Medicine Research Group, Homeopathy
Research Institute, Alliance of Registered Homeopaths, Homeopathy:
Medicine for the 21st Century, European Central Council of Homeopaths)
also allude to the subject of allegedly positive systematic reviews.
The BHA state that 4 of a total of 5 comprehensive
reviews reached positive conclusions. These reviews are (full
references see submission of BHA):
1. Kleijnen et al, BMJ 19911
3. Cucherat et al, Eur J Clin Pharm 20003
4. Linde et al, Lancet 19974
5. Shang et al, Lancet 20055
This statement is misleading for the following
1. The Kleijnen review1 is now 18 years old and
2. Boissel et al2 merely combined p-values of
the included studies. This article is now also outdated. Furthermore
it is not unambiguously positive.
3. Cucherat et al3 is the publication of the
Boissel document which was a EU-sponsored report.
4. Linde et al4 has been re-analysed by various
authors, including Linde himself, and all of the 6 re-analyses
(none of which were cited in the BHA's submission) have come out
negative (see my previous submission to this committee).
5. Shang et al5 very clearly arrived at a devastatingly
negative overall conclusion.
The BHA cites 17 systematic review of which
5 allegedly "concluded there was positive evidence for homeopathy".
These relate to the following conditions.
3. Seasonal allergic rhinitis (2 reviews)8, 9
This statement is equally misleading for the
1. Childhood diarrhoea; this is a meta-analysis
by the US homeopath Jenifer Jacobs which consists solely of her
own 3 trials in this area.6
2. Post-operative ileus; this is our own meta-analysis
which included the important caveat that the only reliable trial
of good quality in our meta-analysis was clearly negative.7
3. Seasonal allergic rhinitis; two reviews/meta-analyses
by Wiesnauer8 as well as Taylor9 are analyses of the respective
authors' own studies.
4. Vertigo; this is a meta-analysis of Vertigohel,
a homeopathically diluted preparation which is administered not
according to the philosophy of homeopathy but that of homotoxicology
(humans are assumed to be poisoned by toxins, particularly those
from pork meat consumption!)10
It seems crucial to stress that one main purpose
of science in general and systematic reviews in particular is
to insist on independent replication of results. Therefore systematic
reviews of author x reviewing nothing but his or her own studies
are complete nonsense.
Here the BHA claim that 4 positive reviews exist.
These relate to
2. Upper respiratory tract infections (2 reviews)12,
This statement is misleading for the following
1. Allergies. The Bellavite article (eCAM 2006)11
is (according to its authors) "a lecture series" not
aimed to provided a meta-analysis. It clearly is not a systematic
review of controlled clinical trials and includes uncontrolled
2. Upper respiratory tract infections. The Bornhft
article (Forsch Komp Med 2006)12 is not a systematic review of
controlled clinical trials but a "Health Technology Assessment"
that includes mostly uncontrolled data. The second Bellaviste
article (eCAM 2006)13 has the same limitations as the first (see
3. Rheumatic disease. This review14 is based
on a selection of the 5 "rheumatic" trials from Linde's
Lancet meta-analysis (see above). Not enough trials in any specific
rheumatic condition were available to allow firm conclusions.
Furthermore, the data can be criticised on the same ground as
Linde's original Lancet article (see above).
It should also be noted that the BHA's evidence
omits several systematic reviews and meta-analysis which were
published. My list is not necessarily complete and includes:
1. Ernst E. Are highly dilute homoeopathic remedies
placebos? Perfusion 1998; 11: 291-292.
2. Morrison B, Lilford R J, Ernst E. Methodological
rigour and results of clinical trials of homoeopathic remedies.
3. Ernst E, Pittler M H. Reanalysis of previous
meta-analysis of clinical trials of homeopathy. J Clin Epidemiol
2000; 53: 1188.
4. Sterne J, Egger M, Smith, G D. Investigating
and dealing with publication and other biases. In Systematic
Reviews in Healthcare: Meta-analysis in Context, eds Egger
M, Smith GD, Altman DG. Pp 189-208. London: BMJ Publishing Group,
5. Ernst E. Classical homoeopathy versus conventional
treatments: a systematic review. Perfusion 1999; 12: 13-15.
It is noteworthy that all of these five "forgotten"
systematic reviews must have been known to the BHA as there were
cited in my "systematic review of systematic reviews"
(Br J Pharmacol 2002),15 and that all of them arrived at negative
6. SPECIFIC CRITICISM
Several submissions (eg those by the BHA, Dr
Sara Eames and the European Central Council of Homeopaths) criticise
specifically the review by Shang et al.5
Dr Eames states that "all meta-analyses
... have been broadly positive until the last one published by
Shang et al in the Lancet". The details provided above clearly
demonstrate that this is erroneous.
The European Central Council of Homeopaths
state that "7 out of 8... reviews/analyses found results
in favour of homeopathy... The 8th study... Shang et al, has since
been severely criticised ..." Again, the details provided
above here show this to be incorrect.
It is, of course, unsurprising that numerous
homeopaths tried to find faults with the Shang meta-analysis.
It is also clear to me that no such paper can ever be entirely
free of limitations. Yet it is equally obvious that Shang et al5
does not stand alone: the vast majority of evaluations by independent
experts failed to show that homeopathic remedies are different
REFERENCE LIST(1) Kleijnen
J, Knipschild P, Ter Riet G. Clinical trials of homoeopathy. BMJ
(2) Boissel J P, Cucherat M, Haugh M, Gauthier
E. Critical literature review on the effectiveness of homoeopathy:
overview of the homoeopathic medicine trials. In: Homoeopathic
Medicine Research Group, Report of the Commission of the European
Communities, Directorate-General XII - Science, Research and Development
E - RTD Actions: Life Sciences and Technologies - Medical
Research, Brussels, Belgium. 1996.
(3) Cucherat M, Haugh M C, Gooch M, Boissel J
P. Evidence of clinical efficacy of homeopathy. A meta-analysis
of clinical trials. Eur J Clin Pharmacol 2000; 56:27-33.
(4) Linde K, Clausius N, Ramirez G, Melchart
D, Eitel F, Hedges L V et al. Are the clinical effects
of homoeopathy placebo effects? A meta-analysis of placebo-controlled
trials. Lancet 1997; 350:834-843.
(5) Shang A, Huwiler-Muntener K, Nartey L, Juni
P, Dorig S, Sterne J A et al. Are the clinical effects
of homoeopathy placebo effects? Comparative study of placebo-controlled
trials of homoeopathy and allopathy. Lancet 2005; 366:726-732.
(6) Jacobs J, Jonas W B, Jimenez-Perez M, Crothers
D. Homeopathy for childhood diarrhoea: combined results and metaanalysis
from three randomized, controlled clinical trials. Pediatr Infect
Dis J 2003; 22:229-234.
(7) Barnes J, Resch K L, Ernst E. Homeopathy
for Postoperative Ileus. J Clin Gastroenterol 1997; 25:628-633.
(8) Wiesenauer M, Ludtke R. A meta-analysis
of the homeopathic treatment of pollinosis with Galphimia glauca.
Forsch Komplementarmed Klass Naturheilkd 1996; 3:230-236.
(9) Taylor M A, Reilly D, Llewellyn-Jones R H,
McSharry C, Aitchison T C. Randomised controlled trial of homoeopathy
versus placebo in perennial allergic rhinitis with overview of
four trial series. BMJ 2000; 321:471-476.
(10) Schneider B, Klein P, Weiser M. Treatment
of vertigo with a homeopathic complex remedy comapred with usual
treatments: a meta-analysis of clinical trials. Arzneimittelforschung
(11) Bellavite P, Ortolani R, Pontarolo F, et
al. Immunology and homeopathy. 4. Clinical studies - Part 2. eCAM
(12) Bornhft G, Wolf U, von Ammon K, Righetti
M, Maxion-Bergemann S, Baumgartner S et al. Effectiveness,
safety and cost-effectiveness of homeopathy in general practice
- summarized health technology assessment. Forsch Komplementmed
(13) Bellavite P, Ortolani R, Pontarolo F, et
al. Immunology and homeopathy. 4. Clinical studies - Part
1. eCAM 2006; 3:293-301.
(14) Jonas W B, Linde K, Ramirez G. Homeopathy
and rheumatic disease. Rheum Dis Clin North Am 2000; 26:117-123,x.
(15) Ernst E. A systematic review of systematic
reviews of homeopathy. Br J Clin Pharmacol 2002; 54:577-582.