1. Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA
2. Department of Internal Medicine, St. Joseph Mercy Ann Arbor Hospital, Ypsilanti, MI, USA
3. Library Public Services, Mayo Clinic, Rochester, MN, USA
4. Robert D and Patricia E Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
5. Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
6. Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA