1. Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, The Netherlands
2. Netherlands Institute for Health Services Research (Nivel), Utrecht, The Netherlands
3. Radboud Institute for Health Sciences, IQ Healthcare
4. Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
5. Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany