1. Department of Epidemiology, Erasmus Medical Centre, Rotterdam, The Netherlands
2. Department of Radiology, Erasmus Medical Centre, Rotterdam, The Netherlands
3. Department of Surgery, Canisius-Wilhelmina Hospital Nijmegen, Nijmegen, The Netherlands
4. Department of Vascular Surgery, Oslo University Hospital, Oslo, Norway
5. Department of Health Management and Health Economics, University of Oslo, Oslo, Norway