1. Resident.
2. Postdoctoral Researcher, Department of Clinical Epidemiology and Biostatistics.
3. Professor of Public Health Methods, Department of Social Medicine, Academic Medical Center, University of Amsterdam.
4. Research Nurse, Department of Anesthesiology.
5. Professor of Anesthesiology Research, Department of Perioperative Medicine, Anesthesiology and Pain Treatment, University Medical Center Utrecht, Utrecht, The Netherlands.