Project Summary Many older adults with a history of colon polyps continue surveillance colonoscopies every 3-5 years to monitor for recurrent polyps, even after age 75 or when in poor health. There are no explicit guidelines for when to stop surveillance, unlike there is for when to stop screening for colorectal cancer (CRC). Currently, approximately 3 million surveillance colonoscopies are performed annually in the US. This number will double to almost 6 million in the next 6 years as the population ages, rates of CRC screening increase, and polyp detection improves. At present, there are critical knowledge gaps that hinder the development of effective strategies to optimize surveillance use in older adults. Most critically, the magnitude of overuse of surveillance in this aging population has not been fully quantified, nor have the factors that influence patient and provider decision-making. Therefore, the objective of this study is to create a detailed characterization of surveillance colonoscopy practice in older adults and to identify current practices and medical decision making around surveillance. We will capitalize on the unique, NCI-funded longitudinal registry specifically designed for colonoscopy, the New Hampshire Colonoscopy Registry (NHCR). NHCR prospectively collects data on nearly 100% of colonoscopies performed in NH and includes detailed colonoscopy information (e.g. indication, findings, pathology, and endoscopist follow-up recommendations). Specifically, we will link patients in NHCR to Medicare claims data in order to perform a detailed assessment of the use of surveillance by life expectancy, identify patients most and least likely to benefit from surveillance based on surveillance findings and life expectancy, and evaluate provider recommendations for next surveillance among older adults. We will also conduct semi-structured interviews with patients, gastroenterologists and primary care providers to identify the multi-level factors involved in the surveillance decision-making process. At the study conclusion, we will have a detailed understanding of the current practice of surveillance colonoscopy in older adults with estimates of important clinical outcomes stratified by life expectancy. Next steps include research to develop and validate multi-level interventions to reduce inappropriate surveillance colonoscopy use. Our overall goal is to maximize high value care among older adults while minimizing risks.