1. Department of Anaesthesiology and Intensive Care Medicine; Copenhagen University Hospital Bispebjerg; Copenhagen; Denmark
2. Department of Clinical Epidemiology; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus; Denmark
3. Department of Gastrointestinal Surgery; Copenhagen University Hospital Herlev; Herlev; Denmark
4. Department of Gastrointestinal Surgery; Aarhus University Hospital; Aarhus; Denmark