1. Division of Gastroenterology, Department of Medicine, McGill University, Montreal, QC, Canada
2. Division of Gastroenterology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
3. Department of Internal Medicine, Hôpital de la Tour and University of Geneva, Geneva, Switzerland
4. Department of Pathology, McGill University, Montreal, QC, Canada
5. Division of Gastroenterology, Department of Medicine, Semmelweis University, Budapest, Hungary
6. Division of Clinical Epidemiology, Department of Medicine, McGill University, Montreal, QC, Canada