. 2020 Nov 17;50(2):317–325. doi: 10.1093/ageing/afaa260
© The Author(s) 2020. Published by Oxford University Press on behalf of the British Geriatrics Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work properly cited. For commercial re-use, please contact journals.permissions@oup.com