1. Division of Gastroenterology and HepatologyUniversity Hospital Zurich and Zurich UniversitySwitzerland
2. Institut de Médecine Sociale et Préventive Unité d’Evaluation des Soins Bio2/02/185Switzerland
3. Division of RheumatologyUniversity Hospital Zurich and Zurich UniversitySwitzerland
4. Department of MedicineDivision of GastroenterologyTriemli HospitalZurichSwitzerland