Intended for healthcare professionals

Letters The truth about sports drinks

Authors’ reply to Betts, Stokes, and Kleiner

BMJ 2012; 345 doi: (Published 14 August 2012) Cite this as: BMJ 2012;345:e5431
  1. Carl Heneghan, clinical reader in evidence based medicine1,
  2. Matthew Thompson, clinical reader1,
  3. Rafael Perera-Salazar, university lecturer in statistics1,
  4. Peter Gill, DPhil candidate1,
  5. Braden O’Neill, DPhil candidate1,
  6. David Nunan, research fellow1,
  7. Jeremy Howick, research fellow1,
  8. Daniel Lasserson, clinical lecturer1,
  9. Kamal Mahtani, clinical lecturer1
  1. 1Centre for Evidence Based Medicine, Department of Primary Care Health Sciences, University of Oxford, Oxford OX1 2ET, UK
  1. carl.heneghan{at}

There is growing recognition of the importance of evidence based methods in scientific laboratory settings, even in animal studies, to improve the safety and efficacy of research.1

In terms of the five references we misclassified, we are posting a correction on the BMJ website and welcome further independent scrutiny. As for the power calculations, two of the studies we are unable to verify, and in another we could not locate the power calculation.2

Betts states, “Given the tight laboratory controls applied in acute experiments, we usually find that 10-20 participants in a crossover design are adequate to detect effects (as shown by the numerous positive effects reported).”3 If this is correct, the results are applicable only to people in tight …

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