1. Department of Geriatric Medicine, Radboud University Medical Centre, Geert Grooteplein Zuid 10 (Route 696), Postbus 9101, 6500 HB Nijmegen, The Netherlands
2. Gerontology Department, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
3. Frailty in Ageing Research (FRIA) Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium
4. Department of Geriatrics, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium