Funding for this research was provided by:
National Institute for Health Research (gmpstrc-2012-1)
Received: 14 June 2018
Accepted: 7 October 2018
First Online: 17 October 2018
Ethics approval and consent to participate
: All participants gave written informed consent prior to participation. Ethical approval for the study was obtained from the University of Manchester Research Ethics Committee (Reference number 14040).
: Not applicable.
: The authors declare that they have no competing interests.
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