Received: 30 May 2019
Accepted: 8 November 2019
First Online: 4 December 2019
Ethics approval and consent to participate
: Aneurin Bevan (Gwent, Wales, UK) University Health Board’s Research Risk Review Committee judged the study as using anonymised data for service improvement purposes and approved it on this basis (ABHB R&D Ref number: SA/410/13).
: Not applicable.
: The authors declare that they have no competing interests.