Funding for this research was provided by:
National Institute for Health Research (RG65966)
Received: 15 June 2018
Accepted: 23 November 2018
First Online: 7 December 2018
Ethics approval and consent to participate
: All participants provided written informed consent to participate in the study. The study was approved by the East of England Cambridge South national institutional review board (13/EE/0325). The research conforms with the principles of the Declaration of Helsinki.
: All individuals involved in this study provided consent for publication.
: The authors declare that they have no competing interests.
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