Letters

Turning a blind eye: Authors have blinkered view of blinding

BMJ 2004; 328 doi: http://dx.doi.org/10.1136/bmj.328.7448.1135-b (Published 06 May 2004) Cite this as: BMJ 2004;328:1135
  1. Stephen J Senn, professor of statistics (stephen@stats.gla.ac.uk)
  1. University of Glasgow, Glasgow G12 8QQ

    EDITOR—Fergusson et al consider a trial to be double blind when the patient, investigators, andoutcome assessors are unaware of the patient's assigned treatment throughout the conduct of the trial.1 They are quite wrong to do so.



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    R A Fisher (1890-1962)

    Credit: A C BARRINGTON BROWN

    The whole point of a successful double blind trial is that there should be unblinding through efficacy. That is to say that there should be …

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