1. Division of Gastroenterology, McGill University Health Centre, Montreal, Québec, Canada
2. Centre for Clinical Epidemiology, Lady Davis Research Institute, Jewish General Hospital, Montreal, Québec, Canada
3. 1st Department of Medicine, Semmelweis University, Budapest, Hungary
4. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Québec, Canada
5. Department of Medicine, McGill University, Montreal, Québec, Canada