Funding for this research was provided by:
British Heart Foundation (PG/12/70/29777)
Received: 10 January 2018
Accepted: 12 June 2018
First Online: 18 June 2018
Ethics approval and consent to participate
: Study procedures were approved by the Loughborough University Ethical Advisory Committee (R13-P25). Under existing ethical guidelines, it was necessary to seek written consent from parents for each child’s participation, and no information could be accessed regarding characteristics of non-respondents.
: Not applicable.
: The authors declare that they have no competing interests.
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