1. Department of Medicine, Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center, Boston, MA
2. Department of General Practice, Erasmus Medical Center, University Medical Center, Rotterdam, the Netherlands
3. Department of General Practice and Family Medicine, University of Bielefeld, Bielefeld, Germany
4. Department of Medicine, Loyola Medicine, MacNeal Hospital, Berwyn, IL