RT Journal Article SR Electronic T1 Preventing recurrent venous thromboembolism JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 38 OP 40 DO 10.1136/dtb.2009.03.0010 VO 47 IS 4 YR 2009 UL http://dtb.bmj.com/content/47/4/38.abstract AB Someone who has had a first episode of venous thromboembolism (VTE) is about 40 times more likely to have an episode in the future than a person who has never experienced such an event.1 Prolonged use of anticoagulation therapy reduces this likelihood of recurrence, but comes with a risk of bleeding. Guidelines cite certain medical conditions that increase the risk of recurrence of VTE (such as cancer and inflammatory bowel disease)2 but, beyond that, there are no reliable tools for stratifying individual patients who are at higher risk of recurrence. Here we review the evidence regarding risk factors for recurrence that might influence the decision to recommend prolonged anticoagulant therapy after a first episode of VTE, and we consider the implications for practice.