Funding for this research was provided by:
National Institute for Health Research
Received: 9 February 2018
Accepted: 30 November 2018
First Online: 20 December 2018
Ethics approval and consent to participate
: An application to HSCIC to hold a national extract of admitted patient care data was approved by the Data Access Advisory Group at the Health and Social Care Information Centre. A self-assessment form was submitted to University of Birmingham Ethics Committee indicating that access to the data had been granted.
: The authors declare that they have no competing interests.
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