Imogen Skene1, Jason Pott2, Eamonn McKeown3. 1. Emergency Department Research Office, Royal London Hospital, Whitechapel, London E1 1BB, United Kingdom. Electronic address: Imogen.skene@barthealth.nhs.uk. 2. Emergency Department Research Office, Royal London Hospital, Whitechapel, London E1 1BB, United Kingdom. Electronic address: Jason.pott@barthealth.nhs.uk. 3. School of Health Sciences, City University London, London EC1V 0HB, United Kingdom. Electronic address: eamonn.mckeown.1@city.ac.uk.