1. Department Epidemiology and Public Health , Sciensano, Brussels, Belgium
2. Department of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium
3. Department of Public Health and Primary Care, Ghent University, Ghent, Belgium
4. Department of Public Health, Epidemiology and Health Economics, WHO Collaborating Centre for Public Health Aspects of Musculoskeletal Health and Ageing, University of Liege, Liège, Belgium