Funding for this research was provided by:
Public Health Research Programme (13/164/32)
Received: 6 November 2019
Accepted: 27 February 2020
First Online: 16 April 2020
Ethics approval and consent to participate
: This trial has been approved by the UCL Ethics Committee (project No. 6960/001). The trial will be conducted in compliance to the Declaration of Helsinki. Informed written consent will be obtained from all participants.
: Not applicable
: The authors declare that they have no competing interests.