Received: 23 November 2020
Accepted: 14 April 2021
First Online: 26 April 2021
: As this project uses de-identified records of routinely data previously collected by the RFDS, specific patient consent forms were not required. The protocol of the study and waiver of consent were approved by the Human Research Ethics Committee of the University of South Australia (Application ID: 202236) and the RFDS Clinical and Health Services Research Committee (CHSRC), which provides oversight for RFDS research projects (Application ID: 201904091). All protocols were carried out in accordance with the requirements of the Australian National Statement on Ethical Conduct in Human Research (2007).
: Not applicable.
: The authors declare that they have no competing interests.