1. Staff Anesthesiologist, Department of Anesthesiology and Intensive Care Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
2. Staff Anesthesiologist, Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Cologne, Germany.
3. Staff Anesthesiologist, Head of Pain Clinic, Department of Anesthesiology and Intensive Care Medicine, University Medical Center Utrecht.
4. Epidemiologist, Department of Anesthesiology and Intensive Care Medicine and Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht
5. Professor of Anesthesiology, Department of Anesthesiology, University Medical Center Utrecht.
6. Professor of Anesthesiology, Head of Pain Clinic, Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany.