1. Department of Surgery, University Hospital Rotterdam—Dijkzigt, The Netherlands
2. Department of Epidemiology and Biostatistics, Medical School, Rotterdam, The Netherlands
3. Institute for Medical Technology Assessment, Erasmus University of Rotterdam, Rotterdam, The Netherlands
4. Department of Ziekenhuis Amstelveen, Amstelveen, The Netherlands
5. Department of Havenziekenhuis, Rotterdam, The Netherlands
6. Department of Albert Schweitzer Ziekenhuis, Dordrecht, The Netherlands