Funding for this research was provided by:
NIHR CTU Support Funding programme
MRC Hubs for Trials Methodology Research
Received: 5 June 2018
Accepted: 23 October 2018
First Online: 16 November 2018
Ethics approval and consent to participate
: The project ethics approval was granted by the REC of the ScHARR at the University of Sheffield (ref: 012041). All Delphi participants provided consent online during registration.
: Not applicable
: The authors declare that they have no competing interests.
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