Funding for this research was provided by:
Raine Medical Research Foundation (2014 Round 3 CRF)
Received: 12 December 2017
Accepted: 15 January 2018
First Online: 19 January 2018
Ethics approval and consent to participate
: This retrospective cohort study only used clinical data that were already collected for administrative purposes; formal patient consent was considered not necessary and ethics approval was waived, and this study was registered with the Royal Perth Hospital Clinical Safety and Quality Unit (No: 22233) with an intention for peer-review publication.
: Consent for publication of non-identifiable data was waived by the Clinical Safety and Quality Unit of Royal Perth Hospital.
: The authors declare that they have no competing interests.
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