1 Centre for Urgent and Emergency Care Research (CURE) Group, School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK. s.mason@sheffield.ac.uk.
2 Department of Emergency Medicine, Beaumont Hospital, Dublin, Ireland.
3 Emergency Care Research Unit (ECRU), Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.
4 Centre for the Business and Economics of Health, The University of Queensland, Brisbane, Australia.