Analysis of a mass colorectal cancer screening program for cost-effectiveness.

Mass screening of the general population with the stool blood test is a costly means of increasing the incidence of colorectal cancer identification; however, the test is worthwhile as a screening tool in patients at risk. We found the incidence of positive results to increase with age, as does the risk of colorectal cancer. Further efforts to increase the incidence of colorectal cancer detection should be directed toward increasing the awareness of primary care physicians and improving their screening practices. We stress that high-risk populations should be given special attention and the use of flexible proctosigmoidoscopes should be encouraged.