Received: 25 November 2019
Accepted: 12 November 2020
First Online: 23 November 2020
Ethics approval and consent to participate
: Our study was approved by the local ethics board, the National Healthcare Group domain specific review board (DSRB) (Reference number: 2015/01155). The NHG DSRB approved the waiver of informed consent from participants and/or their next-of-kin.
: Not applicable.
: The authors declare that they have no competing interests.