1. University of Leipzig; Division of Gastroenterology and Rheumatology Department of Internal Medicine, Neurology and Dermatology; Liebigstrasse 20 Leipzig Germany 04103
2. Universität Leipzig; Zentrum für Klinische Studien (ZKS) Leipzig; Haertelstrasse 16-18 Leipzig Germany 04107
3. Copenhagen Trial Unit, Centre for Clinical Intervention Research, Department 7812, Rigshospitalet; The Cochrane Hepato-Biliary Group; Blegdamsvej 9 Copenhagen Sjaelland Denmark DK-2100
4. Euregio-Klinik GmbH; Internal Medicine; Albert-Schweitzer-Str. 10 Nordhorn Germany 48529