1. Department of Gastroenterology, University Hospital Zurich (USZ), University of Zurich, Zurich, Switzerland
2. Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
3. Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland
4. Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
5. Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois (CHUV), University of Lausanne, Lausanne, Switzerland