1. Centre for Anaesthesiological Research, Department of Anaesthesiology Zealand University Hospital Køge Denmark
2. Department of Anaesthesiology Næstved‐Slagelse‐Ringsted Hospitals Næstved Denmark
3. Department of Clinical Medicine, Faculty of Health and Medical Sciences Copenhagen University Copenhagen Denmark
4. Department of Anaesthesiology and Intensive Care Copenhagen University Hospital Bispebjerg Copenhagen Denmark
5. Department of Anaesthesiology North Zealand Hospital Hillerød Denmark
6. Department of Orthopaedic Surgery and Traumatology Odense University Hospital Odense Denmark
7. Department of Orthopaedic Surgery and Traumatology Odense University Hospital Svendborg Svendborg Denmark
8. Department of Anaesthesiology Vejle Hospital Vejle Denmark
9. Department of Anaesthesiology Gentofte Hospital Copenhagen Denmark
10. Department of Anaesthesiology Odense University Hospital Odense Denmark
11. Department of Orthopaedic Surgery Zealand University Hospital Køge Denmark
12. Department of Orthopaedic Surgery, Næstved‐Slagelse‐Ringsted Hospitals Næstved Denmark
13. Department of Orthopaedic Surgery and Traumatology Copenhagen University Hospital Bispebjerg Copenhagen Denmark
14. Department of Orthopaedic Surgery Gentofte Hospital Copenhagen Denmark
15. Department of Anaesthesiology Odense University Hospital Svendborg Svendborg Denmark
16. Department of Orthopaedic Surgery Vejle Hospital Vejle Denmark
17. Department of Anaesthesiology Private Hospital Capio Gildhøj Brøndby Denmark
18. Copenhagen Trial Unit, Centre for Clinical Intervention Research Copenhagen University Hospital Copenhagen Denmark
19. Department of Regional Health Research, The Faculty of Health Sciences University of Southern Denmark Odense Denmark