1. Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, The Netherlands
2. Division of General Internal Medicine, Department of Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
3. Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
4. Department of Health Services Research and Policy, Australian National University, Canberra, Australia