RT Journal Article SR Electronic T1 Isolated analysis of one time measure: only seeing part of the picture JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 435 OP 435 DO 10.1136/emermed-2012-201697 VO 30 IS 6 A1 Matthew W Cooke YR 2013 UL http://emj.bmj.com/content/30/6/435.abstract AB