RT Journal Article SR Electronic T1 Review: aspirin reduces vascular events but increases bleeding in primary and secondary prevention JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 172 OP 172 DO 10.1136/ebm.14.6.172 VO 14 IS 6 YR 2009 UL http://ebm.bmj.com/content/14/6/172.abstract AB