Funding for this research was provided by:
Economic and Social Research Council (ES/S002588/1)
Wellcome Trust (205407/Z/16/Z)
Article History
Received: 11 September 2019
Accepted: 7 February 2020
First Online: 27 February 2020
Ethics approval
: The study received ethical approval from University College London Research Ethics Committee [14,895/003] and all participants provided online informed consent.
: Not applicable.
: The authors declare that they have no competing interests.