Funding for this research was provided by:
Health Services and Delivery Research Programme (14/21/52)
Received: 12 June 2019
Accepted: 31 October 2019
First Online: 20 November 2019
Ethics approval and consent to participate
: Ethical approval was granted by the University of Exeter Medical School Ethics Committee (REC Application Number: 15/07/070). All participants provided full informed written consent for participation.
: Not applicable.
: The authors declare that they have no competing interests.