1Duke University School of Medicine, Department of Gastroenterology, Durham, NC 2Cooperative Studies Program Epidemiology Center-Durham, Durham VA Health Care System, Durham, NC 3VA Boston Healthcare System, Center for Health Optimization and Implementation Research (CHOIR), Boston, MA 4Boston University Chobanian & Avedisian School of Medicine, Boston, MA 5VA Boston Healthcare System, Department of Quality Management, Boston, MA 6University of Utah School of Medicine, Salt Lake City, UT