1 Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor; Gastroenterology Section, VA Ann Arbor Healthcare System, Ann, MI. Electronic address: etapper@umich.edu.
2 Division of Infectious Diseases, Oregon Health and Sciences University, Portland; Epidemiology Programs, Oregon Health & Science University-Portland State University School of Public Health, Portland.
3 Division of Rheumatology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA; Harvard Medical School, Boston, MA.