1. Department of Surgery; Academic Medical Centre at the University of Amsterdam; The Netherlands
2. Department of NeuroSurgery; Academic Medical Centre at the University of Amsterdam; The Netherlands
3. Department of Clinical Epidemiology; Biostatistics & Bioinformatics; Academic Medical Centre at the University of Amsterdam; The Netherlands
4. Department of Internal Medicine and Department of Quality Assurance & Process Innovation; Academic Medical Centre at the University of Amsterdam; The Netherlands
5. Department of Quality Assurance & Process Innovation,; Academic Medical Centre at the University of Amsterdam and Department of Nursing; Amsterdam School of Health Professions; The Netherlands