1. Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands
2. Department of General Practice/School for Public Health and Primary Care, Maastricht University Medical Centre, Maastricht, The Netherlands
3. Department of Epidemiology, Maastricht University Medical Centre, Maastricht, The Netherlands
4. Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Centre, Maastricht, The Netherlands
5. Department of Surgery, Leiden University Medical Centre, Leiden, The Netherlands
6. Department of Surgery, Breast Unit, St Elizabeth Hospital, Tilburg, The Netherlands
7. Department of Surgery, Laurentius Hospital, Roermond, The Netherlands
8. Department of Surgery, Orbis Medical Centre, Sittard, The Netherlands