1. Research Unit of General Practice, Department of Public Health, University of Southern Denmark, J. B. Winslows Vej 9A, Odense, Denmark
2. Department of Emergency Medicine, Odense University Hospital, 5000 Odense, Denmark
3. Research Unit for General Practice and Section of General Practice, Department of Public Health, Copenhagen University, 1014 Copenhagen K, Denmark
4. Department of Internal Medicine, Regional Hospital Herning, 7400 Herning, Denmark
5. Department of Medical Gastroenterology, Odense University Hospital, 5000 Odense, Denmark