RT Journal Article SR Electronic T1 Review: symptom-based action plans reduce acute care visits more than peak flow-based plans in children with asthma JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 122 OP 122 DO 10.1136/ebm.13.4.122 VO 13 IS 4 YR 2008 UL http://ebm.bmj.com/content/13/4/122.abstract AB