1. Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
2. Division of Gastroenterology, Department of Internal Medicine, Providence Park Hospital, Michigan State University College of Human Medicine, Southfield, Michigan
3. Department of Health Behavior and Health Education, University of Michigan School of Public Health, Ann Arbor, Michigan
4. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
5. Division of Gastroenterology, Department of Internal Medicine, Indiana University School of Medicine, Indianapolis, Indiana
6. Richard L. Roudebush VA Medical Center, Indianapolis, Indiana
7. Regenstrief Institute, Inc, Indianapolis, Indiana
8. VA HSR&D Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, Michigan