1. London School of Hygiene & Tropical Medicine; Cochrane Injuries Group; Room 186 Keppel Street London UK WC1E 7HT
2. London School of Hygiene & Tropical Medicine; Clinical Trials Unit; London UK
3. Rigshospitalet; ITA 4131/Department of Intensive Care; Blegdamsvej 9 Copenhagen Denmark DK-2100
4. Royal London Hospital, Barts Health NHS Trust; Department of Emergency Medicine; Whitechapel London UK E11BB