Funding for this research was provided by:
UK Department of Health (108/0001)
Received: 3 May 2018
Accepted: 6 March 2019
First Online: 20 March 2019
Ethics approval and consent to participate
: Ethical approval was given by Yorkshire and Humber - Sheffield NRES Committee (REC reference: 16/YH/0412). Return of the questionnaire was taken as indicating consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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