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Authors' response
  1. Simone Hashimoto,
  2. Peter J Sterk,
  3. Elisabeth H Bel
  1. Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
  1. Correspondence to Dr Simone Hashimoto, Department of Respiratory Medicine, F5-260, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; s.hashimoto{at}

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We thank Dr Konstantinou for his interesting letter1 in response to our paper on internet-based management of severe asthma.2 He raises a pertinent question about how pragmatic is a study in which the patients have to give their consent to participate? We agree that asking patients to sign for their participation takes the study a step away from real-life settings, but it would be unethical to perform an interventional study without obtaining the patient's permission for randomisation and data to be collected. There are alternative approaches, proposed by Zelen in 1979,3 and mainly used in emergency settings, consisting of post-randomisation consent. In such designs, it is allowed for participants to refuse their allocated treatment or ‘crossover’ to any treatment arm. However, this method is ethically very controversial and could result in some serious statistical drawbacks.4

Another point mentioned by Dr Konstantinou was a possible influence by the ‘Hawthorne effect’ (ie, a change in behaviour due to trial participation rather than treatment) on the outcomes of the study.5 As suggested, it would be ideal to verify the patient's adherence to asthma treatment outside the context of a study. There are reports of objective assessment (blood levels of cortisol) of real-life compliance to oral corticosteroid treatment demonstrating that up to 50% of asthma patients did not adhere to the prescribed medicine.6 Compared with these data, we indeed observed rather high levels of adherence, but given the fact that both groups in our study demonstrated similar adherence as well as comparable ratings for satisfaction with the treatment strategy, we do not believe that the ‘Hawthorne effect’ played a major role in influencing the difference between internet-based and conventional management of severe asthma.


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  • Linked article 200657.

  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.

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