Methods and Economic Considerations: Group 1 Report

Introduction Various modalities have been proposed for population screening in colorectal cancer, including fecal occult blood (FOB) testing, digital rectal examination, barium enema, rigid and flexible sigmoidoscopy, and colonoscopy. Of these, the only tests that have been studied sufficiently to warrant consideration are the guaiac-based FOB test, flexible sigmoidoscopy, and colonoscopy. In this report we consider the evidence relating to these three approaches and present an economic analysis of them, and, lastly, draw some general conclusions. The biases inherent in screening can only be reliably eliminated by population-based randomized trials where the disease-specific mortality in the whole population offered screening (including refusers and those who develop interval cancers after a negative test) is compared with that in the population not offered screening. Thus, for the purposes of examining the efficacy of the different screening methods, emphasis has been placed on evidence from such trials.