1. Robarts Clinical Trials Inc., University of Western Ontario, London, Canada
2. Department of Gastroenterology and Hepatology, University Medical Centre, Ljubljana, Slovenia
3. Department of Gastroenterology, University of Ghent, Ghent, Belgium
4. Department of Medicine, University of Western Ontario, London, Canada
5. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Canada