1. Humanitarian and Conflict Response Institute, School of Arts Languages and Cultures, University of Manchester , Manchester, M15 6JA , UK
2. Newcastle University and St Oswald's Hospice
3. University of Manchester
4. National Institute for Health and Care Research (NIHR) Older People and Frailty Policy Research Unit, Population Health Sciences Institute, Newcastle University , Newcastle-upon-Tyne NE4 5PL , UK
5. School of Health Sciences , Faculty of Biology, Medicine and Health, , Manchester M13 9PL , UK
6. National Institute for Health and Care Research, Older People and Frailty Policy Research Unit, The University of Manchester , Faculty of Biology, Medicine and Health, , Manchester M13 9PL , UK