1. Departments of Acute Internal Medicine and Older Persons' Services, Great Western Hospital NHS Foundation Trust , Swindon SN3 6BB , UK
2. Departments of Care of the Elderly and Stroke Medicine, North Middlesex University Hospital NHS Trust , Sterling Way, London N18 1QX , UK
3. Department of Acute Internal Medicine and Geratology, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital , Oxford OX3 9DU , UK
4. NIHR Applied Research Collaboration (ARC) West Midlands, Warwick Medical School, University of Warwick , Coventry, Warwickshire CV4 3AL , UK
5. Department of Acute Medicine, City Hospital, Sandwell and West Birmingham Hospitals NHS Trust , Birmingham B18 7QH , UK
6. NIHR Oxford Biomedical Research Centre , John Radcliffe Hospital, , Oxford OX3 9DU , UK
7. Oxford University Hospitals NHS Foundation Trust , John Radcliffe Hospital, , Oxford OX3 9DU , UK
8. Nuffield Department of Clinical Neurosciences , Wolfson Centre for Prevention of Stroke and Dementia, , Oxford , UK
9. John Radcliffe Hospital, and the University of Oxford , Wolfson Centre for Prevention of Stroke and Dementia, , Oxford , UK