1. Center for Clinical Epidemiology, Odense University Hospital , Odense , Denmark
2. Research Unit of Clinical Epidemiology, Department of Clinical Research, University of Southern Denmark , Odense , Denmark
3. Department of Medical Gastroenterology, Hospital of Southwest Jutland , Esbjerg , Denmark
4. Department of Regional Health Science, University of Southern Denmark , Esbjerg , Denmark
5. Department of Medical Gastroenterology – S, Odense University Hospital , Odense , Denmark
6. Research Unit of Medical Gastroenterology, Department of Clinical Research, University of Southern Denmark , Odense , Denmark
7. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology , Trondheim , Norway