1. Academic Center for General Practice, Department of Public Health and Primary Care, KU Leuven, Kapucijnenvoer 33, blok J, 3000, Leuven, Belgium
2. Scientific Institute for Quality of Healthcare (IQ Healthcare), Radboud Institute for Health Science (RIHS), Radboud University Medical Center, Radboud University Nijmegen, PO Box 9101, Nijmegen, 6500, HB, The Netherlands