Editor—Homoeopathy arouses strong emotions among believers and non-believers, as the extent of responses to our article suggests; our letter encompasses the points made electronically and above.
Homeopathy is a “waste of time,” states the front cover of the BMJ. This type of response to our scientific paper is inaccurate and unhelpful. We tested the model of homoeopathic immunotherapy as suggested and defined by Reilly et aland observed no clinical effect.5-1 However, as pointed out in our paper, we recognise that this model is not generalisable into current homoeopathic practice. It was used to investigate the different effects of ultramolecular potencies compared with placebo rather than pragmatic homoeopathy.
Feder and Katz suggest that the mechanisms underpinning homoeopathy are best understood through laboratory experimentation. We believe that clinical investigations in humans offer insights that are impossible to achieve in a laboratory. We have suggested some hypotheses that might explain our observed oscillatory effects of homoeopathy, but these require further work5-2; they may be a type I error. We hope that Feder and Katz's suggestion about pragmatic studies does not represent a retreat from rigour.
One reason for conducting our study was that we were concerned by the small size and potential for statistical error and the atypical lack of improvement over time for placebo in the asthma study of Reilly et al.5-1 Our study owes much to the design of this earlier work, but it was not a mere duplication. We rigorously rediagnosed asthma in each patient, and before the study we communicated with Reilly to check that we were following the same protocol in relation to inclusion criteria, dosage regimen, and primary outcome (visual analogue scale).5-1–5-3 Reilly suggests that he used repeated doses of homoeopathic immunotherapy but does not report this in his asthma study.5-1 We were also not aware that each patient was subjected to an individual case conference with, possibly, unreproducible inclusion criteria.5-1
It has been suggested that a hospital based study would select a different population of patients from those in general practice. There is no evidence that this is the case; many high quality asthma effectiveness studies have been conducted in primary care. We selected a group of asthmatic patients in two neighbouring counties who had variable asthma so we could measure change. We cannot understand Reilly's hypothetical differentiation between an effectiveness and efficacy study in this context.
Like us, Taylor et al avoided the pollen season and used potencies of house dust mite while not avoiding the house dust mite season.5-4 The use of Reilly's visual analogue scale on alternate weeks avoided patient data recording fatigue and produced greater compliance over a 20 week study. Our process of randomisation entailed minimisation, thus balancing the treatment groups. Both nurses and patients were unable to guess trial allocation, therefore we are clear that our blinding allocation was completely secure. Had we used a different time point for analysis we might have obtained different (false positive) results.
We analysed response to homoeopathic immunotherapy over 4 months and as a consequence our conclusions are less open to misinterpretation. The only major methodological difference between our study and that of Reilly et al is the lack of a placebo run-in period; an unlikely cause of a significant difference in outcome.5-1
Homoeopathic immunotherapy may be effective in rhinitis,5-3,5-4 but independent investigations have failed to confirm this.5-5 Reilly may have overinterpreted one small such study on asthma. We accept that no two clinical trials are exactly the same, but we believe our study is comparable.5-1 It comes to different conclusions about the differences between homoeopathy and placebo and about treatment effect, reporting that homoeopathy and placebo are significantly different. The robustness of these observations requires careful further work rather than more debate.
References
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5-1.Reilly D, Taylor MA, Beattie NGM, Campbell JH, McSharry C, Aitchison TC, et al. Is evidence for homoeopathy reproducible? Lancet. 1994;344:1601–1606. doi: 10.1016/s0140-6736(94)90407-3. [DOI] [PubMed] [Google Scholar]
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5-2. Hyland ME, Lewith GT. Oscillatory effects in a homeopathic clinical trial: an explanation using complexity theory, and implications for clinical practice. Homeopathy (in press). [DOI] [PubMed]
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5-3.Reilly DT, Taylor MA, McSharry C, Aitshison T. Is homoeopathy a placebo response? Controlled trial of homoeopathic potency, with pollen in hayfever as model. Lancet. 1986;ii:881–886. doi: 10.1016/s0140-6736(86)90410-1. [DOI] [PubMed] [Google Scholar]
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5-4.Taylor MA, Reilly D, Llewellyn-Jones RH, McSharry C, Aitchison TC, Lancaster T, et al. Randomised controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series. BMJ. 2000;321:471–476. doi: 10.1136/bmj.321.7259.471. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
5-5.Aabel S. No beneficial effect of isopathic prophylactic treatment for birch pollen allergy during a low-pollen season: a double-blind, placebo-controlled clinical trial of homeopathic Betula 30c. Br Homeopath J. 2000;89:169–173. doi: 10.1054/homp.1999.0440. [DOI] [PubMed] [Google Scholar]