1 Emergency Department, King's College Hospital, King's Health Partners, London, United Kingdom;Health e-Research Centre, Farr Institute, University of Manchester, Manchester, United Kingdom;Emergency Department, King's College Hospital, King's Health Partners, London, United Kingdom;Heart of England NHS Foundation Trust, Birmingham, United Kingdom;Emergency Department, Derriford Hospital & University of Plymouth, Plymouth, United Kingdom;Emergency Department, King's College Hospital, King's Health Partners, London, United Kingdom.