RT Journal Article SR Electronic T1 BET 2 JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 334 OP 335 DO 10.1136/emj.2011.113928 VO 28 IS 4 YR 2011 UL http://emj.bmj.com/content/28/4/334.abstract AB