1. CJ Leemrijse, PT, PhD, is Researcher, Netherlands Institute for Health Services Research–Allied Health Care (NIVEL), PO Box 1568, 3500 BN, Utrecht, the Netherlands.
2. ICS Swinkels, MSc, is Researcher, Netherlands Institute for Health Services Research–Allied Health Care (NIVEL).
3. C Veenhof, PT, PhD, is Research Coordinator, Netherlands Institute for Health Services Research–Allied Health Care (NIVEL).