c Signi cantly wide CIs, including appreciable bene t /harm and no effect line. d Low number of events. Bibliography: Agnelli et al48 (AMPLIFY-EXT) 328 Evidence-Based Medicine [ 1 4 9 # 2 C H E S T F E B R U A R Y 2 0 1 6 ] another 18 months of treatment or to placebo, and then followed both groups of patients for an additional 24 months after study drug was stopped (Table 12, The study s ndings were consistent with our recommendations in AT9; the additional 18 months of VKA was very effective at preventing recurrent VTE but, once anticoagulation was stopped, the risk of recurrent VTE was the same in those who had been treated for 6 or for 24 months. This new information has not increased the quality of evidence for comparison of a longer vs a shorter, time-limited course of anticoagulation in patients without cancer. 