1. Department of Health Promotion, Care and Public Health Research Institute (CAPHRI), Maastricht University , Maastricht , The Netherlands
2. IVO Research Institute , The Hague , The Netherlands
3. Department of Methodology and Statistics, Care and Public Health Research Institute (CAPHRI), Maastricht University , Maastricht , The Netherlands
4. Department of Family Medicine, Care and Public Health Research Institute (CAPHRI), Maastricht University , Maastricht , The Netherlands