1. CoRPS - Center of Research on Psychology in Somatic Diseases; Department of Medical and Clinical Psychology; Tilburg University; Tilburg The Netherlands
2. Research Methodology Group; Wageningen University and Research Centre; Wageningen The Netherlands
3. CEMO - Centre for Educational Measurement; University of Oslo; Oslo Norway
4. Department of Medical Psychology; Tilburg The Netherlands
5. Department of Surgery; St. Elisabeth Hospital; Tilburg The Netherlands
6. Department of Surgery; Maxima Medical Centre; Eindhoven/Veldhoven The Netherlands
7. Department of Surgery; Amphia Hospital; Breda The Netherlands
8. Department of Surgery; TweeSteden Hospital; Tilburg/Waalwijk The Netherlands