Letter

Masking or blinding?

Blinding is better than masking

BMJ 2007; 334 doi: 10.1136/bmj.39199.461644.3A (Published 3 May 2007)
Cite this as: BMJ 2007;334:918.1

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  1. Kenneth F Schulz, vice president of quantitative sciences1,
  2. Douglas G Altman, director2,
  3. David Moher, director3
  1. 1Family Health International, Research Triangle Park, North Carolina, 27709 USA
  2. 2Centre for Statistics in Medicine, Wolfson College Annexe, Oxford OX2 6UD
  3. 3Chalmers Research Group, Children's Hospital of Eastern Ontario (CHEO) Research Institute, Ottawa, ON, Canada K1H 8L1
  1. kschulz{at}fhi.org

    We agree with Morris et al that “blinding” terminology is probably inappropriate in ophthalmological settings.1 However, we disagree that these settings should ordain terminology for all randomised trials. They describe “masking” done in 1784 and provide dictionary definitions of masking and blinding to buttress their argument for using masking terminology. The techniques used in 1784, however, were …

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