Open letter to the Editor of The Lancet from the Swiss Association of Homoeopathic Physicians (SVHA)

The study on homoeopathy by Shang et al [ ¹ ] from the Department of Social and Preventative Medicine, University of Berne, Prof Egger, published in The Lancet on the 27/8/2005, has been part of the Swiss Complementary Medicine’ Evaluation Programme (PEK). For the last 2 years the authors have been stating in the media that homoeopathic effects are placebo effects, but have withheld the basis of their statement until this year. We do not consider this procedure as very fair. Professor Egger invited us to make our criticism of his study public in a formal ‘Letter to the Editor’. However, our letter was not accepted for publication. We therefore decided to make our comments public in the form of this open letter.

The meta-analysis of homoeopathy by Aijing Shang et al, formed part of the Swiss ‘Complementary Medicine Evaluation Programme’ (PEK). The meta-analysis compares 110 homoeopathic and 110 matched trials of allopathy.

The meta-analysis may be statistically correct. But its validity and practical significance can be seen at a glance: not one single qualified homoeopath would ever treat one single patient in clinical practice as presented in any of the 110 analysed trials! The study cannot give the slightest evidence against homoeopathy because it does not measure real individual (classical) homoeopathy. It confounds real homoeopathic practice with distorted study forms violating even basic homeopathic rules. The correct selection of the homoeopathic remedy almost entirely depends upon the totality of individual symptoms and signs whereas most homoeopathic RCT's use standardized interventions with hardly any practical value and a great inherent chance of producing false negative effects. Even the very few classical studies analysed are distorted by lack of proper follow-up and durations in the narrow frame of RCT's.

Despite this, almost three quarters of the included 110 homeopathic studies of homeopathy show positive results according to previous reviews and meta-analyses.[ ^2–7 ] How does the result from Berne turn out so negative? The negative outcome is based strongly upon a statistical extrapolation from a very small number (8!) of large trials with negative or slightly positive results. From a homoeopathic point of view all the large trials are of very low quality and lack external validity.[ ^8–15 ] Furthermore, in our opinion it is not legitimate to apply the funnel plot method to all the different studies of a complex intervention and mix them in one pot.

There are more serious concerns about the meta-analysis. The report is not transparent. No details of the 110 trials are given nor do the statistical graphics make clear which trial belongs to which result. Thus the study is a ‘black box’ and the reader has to believe it or analyse the trials himself. The study selection is questionable as well: the authors ‘are confident that we identified a near-complete set.… of published trials’. But the above mentioned reviews and meta-analyses include 300–400 homoeopathic RCT's of homeopathy. Therefore, the study is incomplete and violates the standards and rules of the Cochrane collaboration. A more detailed analysis of the study from homoeopathic side is given in German in the statement of the Swiss homoeopathic doctors.[ ¹⁶ ]

The conclusion that homoeopathic effects are due to placebo is scientifically untenable. We wonder how and why Lancet could ignore these facts and announce the ‘end of homoeopathy’. Recent epidemiological studies[ ^17,18 ] in the last years as well as a recent study also Berne University on ADHD[ ¹⁹ ] give evidence of a good practical utility and effectiveness of homoeopathy in clinical practice.

• References

• 1 Shang 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.
• 2 Kleijnen J. et al. Clinical trials of homoeopathy. BMJ 1991; 302: 316-323.
• 3 Boissel J. Critical literature review on the effectiveness of homeopathy: overview over data from homeopathic medicine trials. In: Commission of the European communities, editor. Homeopathic Medicine Research Group. Commission of the European communities, 1996, pp. 196–210.
• 4 Cucherat M. et al. Evidence of clinical efficacy of homeopathy. A meta-analysis of clinical trials. HMRAG Homeopathic Medicines Research Advisory Group. Eur J Clin Pharmacol 2000; 56: 27-33.
• 5 Dean ME. The Trials of Homeopathy—Origins, Structure and Development. KVC Essen, 2004.
• 6 Linde K. et al. Are the effects of homeopathy all placebo effects? A meta-analysis of randomised, placebo controlled trials. Lancet 1997; 350: 834-843.
• 7 Wein C. Qualitätsaspekt klinischer Studien zur Homöopathie. KVC Essen, 2002.
• 8 Attena F., Toscano G., Agozzino E., del Guidice N. A randomized trial in the prevention of influenza-like syndromes by homeopathic management. Revue Epidémiol Santé Publ 1995; 43: 380-382.
• 9 Ferley J.P., Zmirou D., d’Adhemar D., Balducci F. A controlled evaluation of a homeopathic preparation in the treatment of influenza-like syndomes. Brit J Clin Pharmacol 1989; 27: 329-335.
• 10 Ferley J.P., Poutignat N., Azzopardi Y., Charrel M., Zmirou D. Evaluation en médecine ambulatoire de l’activité d’un complexe homéopathique dans la prévention de la grippe et de syndromes grippaux. Immunol Med 1987; 20: 20-28.
• 11 Mokkapatti R. An experimental double-blind study to evaluate the use of Euphrasia in preventing conjunctivitis. Br Homeopath J 1992; 81: 22-24.
• 12 Rottey E.E.D., Verleye G.B., Liagre R.L.P. Het effect van een homeopathische bereiding van micro-organismen bij de preventie van griepsymtomen: een gerandomiseerd dubbel-blind onderzoek in de huisartspraktijk. Tidschr Int Geneeskunde 1995; 11: 54-58.
• 13 Vickers A.J., Fisher P., Smith C., Wyllie S.E., Rees R. Homeopathic Arnica 30x is ineffective for muscle soreness after long-distance running: a randomized, double-blind, placebo-controlled trial. Clin J Pain 1998; 14: 227-231.
• 14 Diefenbach M., Schilken J., Steiner G., Becker H.J. Homöopahische Therapie bei Erkrankungen der Atemwege. Auswertung einer klinischen studie bei 258 Patienten. Z Allg Med 1997; 73: 308-314.
• 15 Papp R., Schuback G. Oscillococcinum in patients with influenza-like syndromes: a placebo-controlled double-blind evaluation. Br Homeopath J 1988; 87: 69-76.
• 16 Stellungnahme des Schweizerischen Vereins homöopathischer Aerztinnen und Aerzte SVHA zur Homöopathiestudie des Instituts für Sozial- und Präventivmedizin ISPM Bern (“Eggerstudie”). Bern 2005, www.svha.ch.
• 17 Güthlin C. et al. Measuring the effects of acupuncture and homeopathy in general practice: an uncontrolled prospective documentation approach. BMC Public Health 2004; 4: 6.
• 18 Becker-Witt C. et al. Diagnoses and treatment in homeopathic medical practice. Forsch Komplementärmed Klass Naturheilkd 2004; 11: 98-103.
• 19 Frei H, et al. Homeopathic treatment of children with attention deficite hyperactive disorder: a randomised, double blind, placebo controlled crossover trial. http://dx.doi.org/10.1007/s00431-005-1735-7. 27.7.2005.