1. Stichting Land van Horne, Vogelsbleek 1, 6001 BE Weert, The Netherlands
2. Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Maastricht University, 6200 MD Maastricht, The Netherlands
3. Department of Methodology and Statistics, Care and Public Health Research Institute (CAPHRI), Maastricht University, 6200 MD Maastricht, The Netherlands
4. Academic Unit of Injury, Recovery and Inflammation Science (IRIS), School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK
5. Department of Family Medicine, Care and Public Health Research Institute (CAPHRI), Maastricht University, 6200 MD Maastricht, The Netherlands