Colonoscopy has emerged as the preferred screening test for colorectal cancer because of its superior adenoma detection rates compared to other screening modalities. The increasing demand for colonoscopy necessitates efficient utilization of colonoscopy by optimization of high quality examinations. The diagnostic accuracy of colonoscopy requires thorough visualization of the colonic mucosa, making bowel preparation a vital element of the procedure and a key quality indicator. Despite its importance, there is currently no uniform, valid way of assessing bowel preparation quality. We have previously developed a novel bowel preparation rating scale, the Boston Bowel Preparation Scale, that is unique in its application during the withdrawal phase of colonoscopy after all cleaning maneuvers have been performed. Another important feature of the Boston Bowel Preparation Scale is its ability to preserve differences in cleanliness between the colonic segments by using individual scores for the right, transverse, and left colon. Our preliminary studies performed at a single academic institution have validated this scale and while its initial performance appears to be promising, the ability to generalize the utility of our results is currently limited. The candidate for this award proposes to educate providers across the country in different practice settings working through a national consortium of endoscopic practices, the Clinical Outcomes Research Initiative (CORI), on use of the Boston Bowel Preparation Scale and demonstrate its reliability, construct validity, and utility as a predictor of polyp detection. Such a tool would contribute significant value to standardizing clinical practice, ensuring quality in colonoscopy, and facilitating research surrounding colonoscopy outcomes. The successful completion of this project will improve our ability to quantify missed pathology rates and to make evidence-based recommendations regarding appropriate surveillance intervals for exams with varying degrees of bowel cleanliness. In addition, this project will allow the candidate to gain invaluable experience in study design, database analysis, and other epidemiologic methods. The candidate will complete a Master's of Science in Epidemiology degree as part of this award. The research will be performed under the mentorship of Dr. Paul Schroy, a well-established investigator in health-services research; in addition, major collaborations will involve CORI and its principal investigator, Dr. David Lieberman. At the completion of the project, the candidate will have gained the experience necessary to enable her to become an effective independent heath-services researcher.