Grant: Operating Grant: Data Analysis Using Existing Databases and Cohorts

While colonoscopy is an important diagnostic and therapeutic test for colorectal cancer (CRC), many scopes are unnecessary. Current evidence shows that those undergoing colonoscopy with no findings have low risk of subsequent CRC. However, how low this risk is has not been established, and further controversy surrounds the interval recommended for repeat screening for those with a previous negative colonoscopy. Our study will build on prior work by conducting a more comprehensive evaluation of those who have had a complete negative colonoscopy within a 20 year time period and examine patient, endoscopist and primary care provider characteristics associated with a second colonoscopy. Our study is needed to establish the risk following a complete negative colonoscopy because existing studies vary in risk estimation and include colonoscopies performed from some time ago that may not reflect the impact of high-quality contemporary colonoscopy. In addition, our study results have the potential to affect practice change by describing recommendations for future screening of patients after a negative colonoscopy and have implications for maximizing efficient use of colonoscopy resources.