1 Division of Gastroenterology and Hepatology, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
2 Department of Epidemiology, University of Washington and Fred Hutchinson Cancer Research Center, Seattle Washington.
3 Division of General Internal Medicine, Veterans Affairs Sound Healthcare System and University of Washington, Seattle, Washington.
4 Division of Gastroenterology, Veterans Affairs Puget Sound Healthcare System and University of Washington, Seattle, Washington.
5 Division of Gastroenterology, Veterans Affairs San Diego Healthcare System and University of California, San Diego, California.
6 Research and Development, Veterans Affairs Puget Sound Healthcare System, Seattle, Washington.
7 Division of Gastroenterology and Research and Development, Veterans Affairs Puget Sound Healthcare System and University of Washington, Seattle, Washington.