Funding for this research was provided by:
Medical Research Council (MR/N028287/1)
Received: 27 September 2019
Accepted: 20 December 2019
First Online: 14 January 2020
Ethics approval and consent to participate
: The CAST study protocol was approved by the Northern and Yorkshire Multicentre Research Ethics Committee (MREC/2/3/9), and the Research and Ethics Committees for each collaborating hospital. All individuals provided written informed consent. Additional ethics approval was not sought to perform this secondary analysis.
: Not applicable.
: The authors declare that they have no competing interests.