Funding for this research was provided by:
Medical Research Council (MC_UU_12019/1)
Text and Data Mining valid from 2019-11-28
Received: 10 October 2018
Accepted: 31 October 2019
First Online: 28 November 2019
Ethics approval and consent to participate
: Ethical approval for the most recent visit was given by Queen Square Research Ethics Committee (13/LO/1073) and Scotland A Research Ethics Committee (14/SS/1009). Written informed consent was provided by participants for each visit.
: Not applicable.
: The authors declare that they have no competing interests.