British Journal of Surgery Volume 96 Issue 4, Pages 342 - 349

K. S. Gurusamy 1 *, C. Gluud 2, D. Nikolova 2, B. R. Davidson 1
1University Department of Surgery, Royal Free Hospital and University College School of Medicine, London, UK
2Copenhagen Trial Unit, Centre for Clinical Intervention Research, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark

The causes of bias in surgical trials as described by The Cochrane Collaboration, and the methods that can be used to avoid them, are reviewed