Funding for this research was provided by:
British Heart Foundation (PG/11/51/28986, SP 14/4/31123)
Medical Research Council (MC_UU_1201/5)
National Institute for Health Research (NF-SI-0166-10196)
Text and Data Mining valid from 2018-04-19
Received: 19 October 2017
Accepted: 11 April 2018
First Online: 19 April 2018
Ethics approval and consent to participate
: Ethical approval for this study was provided by the School for Policy Studies Research Ethics Committee at the University of Bristol and written parental consent was provided for both parent and child participation.
: As part of the informed consent process parents provided written consent for publication for both parent and child data.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.