1. Research group Healthy Ageing, Allied Health Care and Nursing, University of Applied Sciences Groningen, Groningen, the Netherlands
2. ZuidOostZorg, center for Elderly Care, Drachten, the Netherlands
3. Department of General Practice and Elderly Care Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
4. Frailty in Ageing Research Group and Gerontology Department, Vrije Universiteit Brussel, Brussels, Belgium
5. Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
6. Department of Neuroscience, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
7. Department of Medicine, Division of Neurology, University of Toronto, Toronto, ON, Canada
8. Jeff and Diane Ross Movement Disorders Clinic, Baycrest Center for Geriatric Health, Toronto, ON, Canada