1. W.T.M. Enthoven, MD, Department of General Practice, Erasmus MC, University Medical Center, Post Box 2040, 3000 CA Rotterdam, the Netherlands.
2. J. Geuze, MD, Department of General Practice, Erasmus MC, University Medical Center.
3. J. Scheele, PhD, Department of General Practice, Erasmus MC, University Medical Center.
4. S.M.A. Bierma-Zeinstra, PhD, Department of General Practice and Department of Orthopaedics, Erasmus MC, University Medical Center.
5. H.J. Bueving, MD, PhD, Department of General Practice, Erasmus MC, University Medical Center.
6. A.M. Bohnen, MD, PhD, Department of General Practice, Erasmus MC, University Medical Center.
7. W.C. Peul, MD, PhD, Department of Neurosurgery, Leiden University Medical Center, Leiden, the Netherlands.
8. M.W. van Tulder, PhD, Department of Health Sciences and EMGO Institute for Health and Care Research, Faculty of Earth and Life Sciences, VU University Amsterdam, the Netherlands.
9. M.Y. Berger, MD, PhD, Department of General Practice, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
10. B.W. Koes, PhD, Department of General Practice, Erasmus MC, University Medical Center.
11. P.A.J. Luijsterburg, PhD, Department of General Practice, Erasmus MC, University Medical Center.