1. Department of Intestinal Failure and Liver Diseases , Rigshospitalet, Copenhagen , Denmark
2. Department of Public Health, Section of Biostatistics, University of Copenhagen , Copenhagen , Denmark
3. Copenhagen Center for Inflammatory Bowel Disease in Children, Adolescents and Adults, Copenhagen University Hospital - Amager and Hvidovre , Hvidovre , Denmark
4. Department of Clinical Medicine, University of Copenhagen , Copenhagen , Denmark