This paper reviews the design of a large multicenter clinical trial currently being conducted to test the equivalence of two screening procedures for colorectal polyps. The primary outcome is the sensitivity and specificity of the new and standard procedures for detecting subjects with and without polyps of a size > or =6 mm, respectively. An important secondary outcome is the accuracy of these procedures in detecting individual polyps. A total of 619 participants underwent virtual colonoscopy, the new procedure, followed by conventional colonoscopy, the standard procedure. Strategies for the design and implementation of the study are shared as well as the challenges encountered.
Copyright 2002 Elsevier Science Inc.