RT Journal Article SR Electronic T1 Side effects of decision rules, or the law of unintended consequences JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 2 OP 3 DO 10.1136/emermed-2018-208151 VO 36 IS 1 A1 Ellen J Weber A1 Edward W Carlton YR 2019 UL http://emj.bmj.com/content/36/1/2.abstract AB