Registers for clinical trials already existBMJ 1995; 310 doi: https://doi.org/10.1136/bmj.310.6994.1604 (Published 17 June 1995) Cite this as: BMJ 1995;310:1604
- J A Muir Gray
- Director of research and development NHS Executive, Anglia and Oxford, Oxford OX3 7LF
EDITOR,—In their editorial on misleading meta-analyses, Matthias Egger and George Davey Smith point out that bias is a major cause of error because of the tendency for negative trials …
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