Jan Geertzen1, Harmen van der Linde2, Kitty Rosenbrand3, Marcel Conradi4, Jos Deckers5, Jan Koning6, Hans S Rietman7, Dick van der Schaaf8, Rein van der Ploeg5, Johannes Schapendonk9, Ernst Schrier10, Rob Smit Duijzentkunst11, Monica Spruit-van Eijk12, Gerbrig Versteegen10, Harrie Voesten6. 1. Department of Rehabilitation Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands j.h.b.geertzen@umcg.nl. 2. KINOS, Rotterdam, The Netherlands. 3. CBO, Utrecht, The Netherlands. 4. De Hoogstraat, Utrecht, The Netherlands. 5. Royal Dutch Society for Physical Therapies, Utrecht, The Netherlands. 6. Dutch Society for Surgery, Utrecht, The Netherlands. 7. University of Twente, Enschede, The Netherlands. 8. Dutch Orthopedic Society, Utrecht, The Netherlands. 9. Dutch Society of Anaesthesiology, Utrecht, The Netherlands. 10. Netherlands Institute of Psychologists, Utrecht, The Netherlands. 11. Netherlands Association for Occupational and Industrial Medicine, Utrecht, The Netherlands. 12. Dutch Association for Elderly Care Specialists, The Netherlands.