Funding for this research was provided by:
Medical Research Foundation (MR/N013700/1)
Received: 21 October 2020
Accepted: 17 March 2021
First Online: 31 March 2021
: All participants in the interview studies gave written informed consent, and ethical approval was obtained from London-City and East Research Ethics Committee and South London (18/LO/0050).
: All participants gave consent to publish the study;
: The authors declare that they have no competing interests.