Letter

Homoeopathy versus placebo in perennial allergic rhinitis

BMJ 2001; 322 doi: 10.1136/bmj.322.7279.169 (Published 20 January 2001)
Cite this as: BMJ 2001;322:169

Access to the full text of this article requires a subscription or payment. Please log in or subscribe below.

Statistics in study were flawed

  1. Barry Miller (barry.miller@bigfoot.com), consultant anaesthetist
  1. Royal Oldham Hospital, Oldham OL1 2JH
  2. Asthma and Allergy Research Group, Department of Clinical Pharmacology, Ninewells Hospital, Dundee DD1 9SY
  3. Department of Health Sciences and Clinical Evaluation, University of York, York YO10 5DD
  4. Department of Evidence Based Medicine, Medical Advisory Service of Social Sickness Funds (MDS), 45116 Essen, Germany
  5. Derby DE22 1HT
  6. University Department of Medicine, Glasgow Royal Infirmary, Glasgow G31 2ER
  7. Department of Psychological Medicine, University of Sydney, New South Wales 2000, Australia
  8. University Department of Immunology, Western Infirmary, Glasgow G11 6NT
  9. Department of Statistics, University of Glasgow, Glasgow G12 8QQ

    EDITOR—Taylor et al come to the conclusion that their study of homoeopathy versus placebo in perennial allergic rhinitis “has failed to confirm our original hypothesis that homeopathy is a placebo.”1 Unfortunately, the statistics do not prove that.

    The basis for the study was a prestudy power calculation that required 120 patients to prove the hypothesis with a 5% significance and an 80% power.2 In fact, the authors only recruited 51 patients but analysed the results as if they had the required number. Their only conclusion was that they did not have enough data to make a conclusion.

    If we accept the availability of only 51 patients at the outset, what are the relevant calculations? The power calculation is only 43%, and to maintain the power calculation at 80% the P value becomes 34%. The only conclusion is that the trial is not able to prove anything.

    Footnotes

    • Competing interests None declared.

    References

    1. 1.↵
      1. Taylor MA,
      2. Reilly D,
      3. Llewellyn-Jones RH,
      4. McSharry C,
      5. Aitchison TC
      .Randomised controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series [with commentary by T Lancaster, A Vickers].BMJ2000; 321:471–476. (19-26 August.)
      OpenUrlFREE Full Text
    2. 2.↵
      1. Reilly DT,
      2. Taylor MA,
      3. McSharry C,
      4. Aitchison T
      .Is homoeopathy a placebo response? Controlled trial of homoeopathic potency, with pollen in hayfever as model.Lancet1986; ii:881–886.

    Study shows dissociation between objective and subjective responses to homoeopathy in allergic rhinitis

    1. Brian J Lipworth (b.j.lipworth@dundee.ac.uk), professor of allergy and respiratory medicine
    1. Royal Oldham Hospital, Oldham OL1 2JH
    2. Asthma and Allergy Research Group, Department of Clinical Pharmacology, Ninewells Hospital, Dundee DD1 9SY
    3. Department of Health Sciences and Clinical Evaluation, University of York, York YO10 5DD
    4. Department of Evidence Based Medicine, Medical Advisory Service of Social Sickness Funds (MDS), 45116 Essen, Germany
    5. Derby DE22 1HT
    6. University Department of Medicine, Glasgow Royal Infirmary, Glasgow G31 2ER
    7. Department of Psychological Medicine, University of Sydney, New South Wales 2000, Australia
    8. University Department of Immunology, Western Infirmary, Glasgow G11 6NT
    9. Department of Statistics, University of Glasgow, Glasgow G12 8QQ

      EDITOR—Taylor et al show the apparent dissociation between objective responses to homoeopathy (domiciliary nasal peak flow) and subjective responses (nasal symptoms) after four weeks in 50 patients with allergic rhinitis.1 Few randomised controlled studies have measured domiciliary peak nasal inspiratory flow rate in allergic rhinitis, which makes these results all the more intriguing.

      In one of those studies, of 38 patients with allergic rhinitis, nasal symptom scores showed significant (P<0.01) correlations with morning and evening domiciliary nasal peak flow after four weeks of treatment.2 The mean overall improvement in domiciliary nasal peak flow was 25 l/min in response to four weeks of antihistamine, which is comparable to the magnitude of the homoeopathy peak flow response (20 l/min).

      Perhaps a longer period of homoeopathy or a different dose might have resulted in a subjective treatment response in patients with allergic rhinitis. Moreover, we need to know how …

      Access to the full text of this article requires a subscription or payment

      Subscribe

      Article access

      Article access for 1 day

      Purchase this article for £20 $30 €32*

      The PDF version can be downloaded as your personal record

      * Prices do not include VAT

      Rapid responses

      THIS WEEK'S POLL

      BMJ most popular