1. Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
2. Department of Neurology, Oslo University Hospital, Oslo, Norway
3. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
4. Department of Internal Medicine, Bærum Hospital, Vestre Viken, Norway
5. Department of Physiotherapy, Oslo University Hospital, Oslo, Norway
6. Department of Internal Medicine, Central Hospital, Karlstad, Sweden
7. School of Medical Sciences, Örebro University, Örebro, Sweden