1. Resident.
2. Consultant, Department of Clinical Biochemistry, Statens Serum Institute.
3. Research Assistant, Department of Biostatistics, University of Copenhagen. ∥ The ISPOCD2 Investigators are listed in the appendix.
4. Associate Professor, Department of Anesthesia 4132, Center of Head and Orthopedics, Rigshospitalet, Copenhagen University Hospital.