1. Department of Health Sciences, University of Leicester School of Medicine, Centre for Medicine University of Leicester Lancaster Road, Leicester, United Kingdom of Great Britain and Northern Ireland
2. Section of Social Medicine, Kobenhavns Universitet Det Samfundsvidenskabelige Fakultet, Kobenhavn, Denmark
3. Gerontology & Geriatrics, Leiden University Medical Centre, Leiden, Netherlands
4. Section of Ageing and Health, University of Dundee, Ninewells Hospital, Dundee, United Kingdom of Great Britain and Northern Ireland