Received: 9 August 2019
Accepted: 27 November 2019
First Online: 7 January 2020
Ethics approval and consent to participate
: This retrospective audit complied with the United Kingdom National Health Service guidelines for clinical audit and service development, and met with approval from the Health Research Authority. In keeping with United Kingdom guidelines, all patient data was anonymised prior to analysis (ExternalRef removed).
: Not relevant
: The authors declare that they have no competing interest