Y Backes1, A Moss2,3, J B Reitsma4, P D Siersema1,5, Leon M G Moons1. 1. Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands. 2. Department of Endoscopic Services, Western Health, Melbourne, Victoria, Australia. 3. Department of Medicine, Melbourne Medical School-Western Precinct, The University of Melbourne, St. Albans, Victoria, Australia. 4. Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. 5. Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, The Netherlands.