1. East and North Hertfordshire NHS Trust Lister Hospital, , Stevenage SG1 4AB , United Kingdom
2. Royal Free London NHS Trust Barnet Hospital, , Barnet EN5 3DJ , United Kingdom
3. University of Cambridge School of Clinical Medicine, , Cambridge CB2 0SP , United Kingdom
4. London North West University Healthcare NHS Trust Northwick Park Hospital, , Harrow HA1 3UJ , United Kingdom
5. Walsall Healthcare NHS Trust Walsall Manor Hospital, , Walsall WS2 9PS , United Kingdom
6. University College London Hospital (UCLH) NHS Foundation Trust Emergency Department, , London NW1 2BU , United Kingdom