University of Maryland, Baltimore, Department of Medicine, Division of Gastroenterology and Hepatology, Baltimore, MD, United States. Electronic address: rcross@medicine.umaryland.edu. University of Maryland, Baltimore, Department of Medicine, Division of Gastroenterology and Hepatology, Baltimore, MD, United States. University of Maryland, Baltimore, Department of Epidemiology and Public Health, Baltimore, MD, United States. University of Maryland, Baltimore, Department of Epidemiology and Public Health, Baltimore, MD, United States; Veterans Affairs Cooperative Studies Program, Perry Point, MD, United States. CircleLink Health, Stamford, CT, United States. University of Pittsburgh, Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, Pittsburgh, PA, United States. Vanderbilt University, Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, Nashville, TN, United States.