1 Geriatric Unit, Department of Medicine, University of Palermo, Palermo, Italy. nicola.veronese@unipa.it.
2 World Health Organization Collaborating Centre for Public Health Aspects of Musculoskeletal Health and Aging, Liege, Belgium.
3 Division of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium.
4 Ageing and Health Unit, Department of Maternal, Newborn, Child and Adolescent Health & Ageing, WHO HQ, Geneva, Switzerland.
5 Division of Bone Diseases, Faculty of Medicine, Geneva University Hospitals, University of Geneva, Geneva, Switzerland.
6 MRC Life Course Epidemiology Unit, Southampton General Hospital, University of Southampton, Southampton, UK.
7 Demographic Change and Healthy Aging Unit, Social Determinants of Health, World Health Organization, Geneva, Switzerland.
8 Epidemiology, Monitoring and Evaluation Unit, Maternal, Newborn, Child, Adolescent Health and Ageing, World Health Organization, Geneva, Switzerland.