Understanding the Results of a Randomized Trial of Screening Colonoscopy

For more than two decades, colonoscopy has been recommended as one of several available options for colorectal cancer screening, and it has been the predominant form of screening for colorectal cancer used in the United States. However, the best evidence to support its use has been limited to data from cohort studies, which have estimated that this type of screening has been associated with a 40 to 69% decrease in the incidence of colorectal cancer and a 29 to 88% decrease in the risk of death from this disease.1 Unlike randomized, controlled trials, which have provided support for fecal occult . . .