RT Journal Article SR Electronic T1 BET 1 JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 242 OP 243 DO 10.1136/emj.2009.089656a VO 27 IS 3 YR 2010 UL http://emj.bmj.com/content/27/3/242.2.abstract AB