1. Centre for Anaesthesiological Research, Department of Anesthesiology Zealand University Hospital Køge Denmark
2. Department of Anesthesiology Nykøbing Falster Hospital Nykøbing Falster Denmark
3. Department of Anesthesiology Nordland Hospital Trust Bodø Norway
4. Department of Clinical Medicine Copenhagen University Copenhagen Denmark
5. Department of Anesthesiology University Hospital Northern Norway Tromsø Norway
6. Copenhagen Trial Unit, Centre for Clinical Intervention Research Copenhagen University Hospital, Rigshospitalet Copenhagen Denmark
7. Department of Regional Health Research, The Faculty of Health Sciences University of Southern Denmark Odense Denmark