1. Section of Social Medicine, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
2. Center for Healthy Aging, University of Copenhagen, Copenhagen K, Denmark
3. Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Sweden
4. Faculty of Social Sciences and Gerontology Research Center (GEREC), University of Tampere, Finland
5. Institute for Advanced Social Research, University of Tampere, Finland
6. Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health Oslo, Norway
7. The Icelandic Gerontological Research Center, Landspitali University Hospital and University of Iceland, Reykjavik, Iceland
8. Faculty of Health Promotion, Sport and Leisure Studies University of Iceland, Reykjavík, Iceland