1. Department of Gastroenterology, Kanta-Häme Central Hospital, Hämeenlinna, Finland
2. Faculty of Medicine, University of Helsinki, Helsinki, Finland
3. Department of Gastroenterology, Turku University Hospital, Turku, Finland
4. Department of Internal Medicine, Central Finland Central Hospital, Jyväskylä, Finland
5. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, and University of Tampere, Tampere, Finland
6. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland
7. Faculty of Social Sciences, Tampere University, Tampere, Finland
8. Gastroenterology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland