Funding for this research was provided by:
National Institute for Health Research (163057)
Received: 13 May 2019
Accepted: 7 January 2020
First Online: 6 February 2020
Ethics approval and consent to participate
: UCL Research Ethics Committee (Project ID: 6887/001) and National Research Ethics Service Committee of South Central-Oxford C (reference: 15/SC/0223) approved the study.Written consent was obtained from all study participants prior to using either their data or quotes from their contribution in this manuscript.
: Not applicable.
: The authors declare that they have no competing interests.