Footnotes

• Contributors LFI conceptualised, designed and coordinated the study, contacted participants, drafted the initial manuscript and approved the final manuscript as submitted. PAB, FEB and SMH were involved in the design of the study, data analysis, reviewed and revised the manuscript and approved the final draft. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

• Funding This study was funded in part by grants from The Royal Children’s Hospital (RCH) Foundation, the Murdoch Children’s Research Institute (MCRI), the Victorian Department of Health, Melbourne, Australia. LFI was supported in part by a scholarship from AVANT Mutual Group Ltd, Melbourne, the Melbourne Children’s Campus Postgraduate Health Research Scholarship and the Doctor Nicholas Collins Fellowship. PAB was in part supported by a Melbourne Campus Clinician Scientist Fellowship, Melbourne, Australia. FEB was supported in part by a grant from the RCH Foundation and a Melbourne Campus Clinician Scientist Fellowship, Melbourne, Australia, and a National Health and Medical Research Council (NHMRC) Practitioner Fellowship, Canberra, Australia. The emergency research group, MCRI, is in part supported by an NHMRC Centre for Research Excellence Grant for Paediatric Emergency Medicine, Canberra, Australia, and the Victorian government infrastructure support programme.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.

• Patient consent for publication Not required.