1. Department of Neurosurgery, Erasmus Medical Center, Rotterdam, The Netherlands.
2. Department of Neurosurgery, Virginia Commonwealth University Medical Center, Richmond, Virginia.
3. Public Health Sciences, University of Edinburgh Medical School, Edinburgh, United Kingdom.
4. University of Glasgow and Royal College of Physicians and Surgeons, Glasgow, United Kingdom.
5. Center for Medical Decision Making, Department of Public Health, Erasmus Medical Center, Rotterdam, The Netherlands.