1. Institute of Social & Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland;
2. Division of Gastroenterology & Hepatology, Lausanne University Hospital, Lausanne, Switzerland;
3. Division of Gastroenterology & Hepatology, Basel University Hospital, Basel, Switzerland;
4. Clinique La Source-Beaulieu, Crohn and Colitis Center, Lausanne, Switzerland