Funding for this research was provided by:
National Institute for Health Research Policy Research Programme (027/0089)
Text and Data Mining valid from 2019-06-10
Received: 8 October 2018
Accepted: 21 May 2019
First Online: 10 June 2019
Ethics approval and consent to participate
: Data were obtained in an anonymised format, and the study was not eligible for institutional ethical approval and participant consent. There were no administrative permissions required to access the raw data from the Hospital Episode Statistics (HES) database, as the data was provided by the Department of Health, England, (the custodian of the HES database) in an anonymised format.
: Not applicable.
: The authors declare that they have no competing interests.