RT Journal Article SR Electronic T1 Review: long acting β agonists increase severe asthma exacerbations and asthma related deaths in children and adults JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 10 OP 10 DO 10.1136/ebm.12.1.10 VO 12 IS 1 YR 2007 UL http://ebm.bmj.com/content/12/1/10.abstract AB