1. Department of Gastrointestinal Surgery; Helsinki University Central Hospital; Helsinki Finland
2. Unit of Primary Health Care; Helsinki University Central Hospital; Helsinki Finland
3. Department of General Practice; University of Helsinki; Helsinki Finland
4. Unit of Primary Health Care; Turku University Hospital; Turku Finland
5. Research Department; The Social Insurance Institution of Finland; Turku Finland
6. Department of Public Health; University of Helsinki; Helsinki Finland
7. Department of Medicine; Clinic of Gastroenterology; Helsinki University Central Hospital; Helsinki Finland
8. Institute of Clinical Medicine; University of Helsinki; Helsinki Finland