***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Objective : The phase III EINSTEIN DVT and EINSTEIN PE trials demonstrated the potential of oral rivaroxaban for the treatment of deep vein thrombosis ( DVT ) and pulmonary embolism ( PE ) . The length of initial hospitalization in patients presenting with either symptomatic DVT or PE was assessed using hospitalization records from these trials . Methods : Analyses were carried out in the intention-to-treat population , using non-parametric and parametric statistical methods . Results : Overall , 52 % ( 1781/3434 ) of EINSTEIN DVT patients and 90 % ( 4328/4821 ) of EINSTEIN PE patients were admitted to hospital . The proportion of hospitalized patients with a length of stay of five or fewer days receiving rivaroxaban was 54 % compared with 31 % for enoxaparin/vitamin K antagonist ( VKA ) in patients with DVT . For patients with PE , the corresponding values were 45 % and 33 % . Stays of 6–10 days were observed in 29 % of rivaroxaban-treated patients compared with 45 % of enoxaparin/VKA-treated patients for DVT . For patients with PE , these values were 39 % and 46 % in the rivaroxaban and enoxaparin/VKA groups , respectively . Overall , length of stay was significantly shorter in the rivaroxaban group , compared with the enoxaparin/VKA group across all analyses performed ( p < 0.0001 ) . Across regions , the observed admission rates and length of stay duration varied greatly : Asia had the longest overall hospitalization rates , whereas the lowest rates were reported in North America , Australia and New Zeal and . Nevertheless , a consistent trend was observed : length of hospital stay in  patients with DVT or PE  receiving rivaroxaban was shorter than , or at least similar to , patients receiving enoxaparin/VKA . Conclusion : A single-drug regimen with rivaroxaban may reduce the burden on healthcare systems and patients , and provides effective and well tolerated treatment . The studies shared an open-label design that allowed comparison of initial hospitalization , but limitations include the well monitored clinical trial setting in which decisions on admission and discharge could vary from real-world management Background — Patients with a first episode of unprovoked venous thromboembolism have a high risk of recurrence after discontinuation of anticoagulant therapy . Extending anticoagulation reduces the risk of recurrence but is associated with increased bleeding . Sulodexide , a glycosaminoglycan , exerts antithrombotic and profibrinolytic actions with a low bleeding risk when administered orally , but its benefit for preventing recurrent venous thromboembolism is not well known . Methods and Results — In this multicenter , double-blind study , 615 patients with first-ever unprovoked venous thromboembolism who had completed 3 to 12 months of oral anticoagulant treatment were r and omly assigned to sulodexide 500 lipasemic units twice daily or placebo for 2 years , in addition to elastic stockings . The primary efficacy outcome was recurrence of venous thromboembolism . Major or clinical ly relevant bleeding was the primary safety outcome . Venous thromboembolism recurred in 15 of the 307 patients who received sulodexide and in 30 of the 308 patients who received placebo ( hazard ratio , 0.49 ; 95 % confidence interval [ CI ] , 0.27–0.92 ; P=0.02 ) . The analysis in which lost to follow-up was assigned to failure yielded a risk ratio among treated versus control subjects of 0.54 ( 95 % confidence interval , 0.35–0.85 ; P=0.009 ) . No major bleeding episodes occurred ; 2 patients in each treatment group had a clinical ly relevant bleeding episode . Adverse events were similar in the 2 groups . Conclusion — Sulodexide given after discontinuation of anticoagulant treatment reduced the risk of recurrence in patients with unprovoked venous thromboembolism , with no apparent increase of bleeding risk . Clinical Trial Registration — URL : https://www . clinical trialsregister.eu/. Identifier : EudraCT number 2009 - 016923 - 77 Background — Predicting the risk of recurrent venous thromboembolism ( VTE ) in an individual patient is often not feasible . We aim ed to develop a simple risk assessment model that improves prediction of the recurrence risk . Methods and Results — In a prospect i ve cohort study , 929 patients with a first unprovoked VTE were followed up for a median of 43.3 months after discontinuation of anticoagulation .  We excluded patients with a strong thrombophilic defect such as a natural inhibitor deficiency , the lupus anticoagulant , and homozygous or combined defects . A total of 176 patients ( 18.9 % ) had recurrent VTE . Preselected clinical and laboratory variables ( age , sex , location of VTE , body mass index , factor V Leiden , prothrombin G20210A mutation , D-dimer , and in vitro thrombin generation ) were analyzed in a Cox proportional hazards model , and those variables that were significantly associated with recurrence were used to compute risk scores . Male sex ( hazard ratio versus female sex 1.90 , 95 % confidence interval 1.31 to 2.75 ) , proximal deep vein thrombosis ( hazard ratio versus distal 2.08 , 95 % confidence interval 1.16 to 3.74 ) , pulmonary embolism ( hazard ratio versus distal thrombosis 2.60 , 95 % confidence interval 1.49 to 4.53 ) , and elevated levels of D-dimer ( hazard ratio per doubling 1.27 , 95 % confidence interval 1.08 to 1.51 ) were related to a higher recurrence risk . Using these variables , we developed a nomogram that can be used to calculate risk scores and to estimate the cumulative probability of recurrence in an individual patient . The model was cross vali date d , and patients were assigned to different risk categories based on their risk score . Recurrence rates corresponded well with the different risk categories . Conclusions — By use of a simple scoring system , the assessment of the recurrence risk in patients with a first unprovoked VTE and without strong thrombophilic defects can be improved BACKGROUND The direct oral thrombin inhibitor dabigatran has a predictable anticoagulant effect and may be an alternative therapy to warfarin for patients who have acute venous thromboembolism . METHODS In a r and omized , double-blind , noninferiority trial involving patients with acute venous thromboembolism who were initially given parenteral anticoagulation therapy for a median of 9 days ( interquartile range , 8 to 11 ) , we compared oral dabigatran , administered at a dose of 150 mg twice daily , with warfarin that was dose-adjusted to achieve an international normalized ratio of 2.0 to 3.0 . The primary outcome was the 6-month incidence of recurrent symptomatic , objective ly confirmed venous thromboembolism and related deaths . Safety end points included bleeding events , acute coronary syndromes , other adverse events , and results of liver-function tests . RESULTS A total of 30 of the 1274 patients r and omly assigned to receive dabigatran ( 2.4 % ) , as compared with 27 of the 1265 patients r and omly assigned to warfarin ( 2.1 % ) , had recurrent venous thromboembolism ; the difference in risk was 0.4 percentage points ( 95 % confidence interval [ CI ] , -0.8 to 1.5 ; P<0.001 for the prespecified noninferiority margin ) . The hazard ratio with dabigatran was 1.10 ( 95 % CI , 0.65 to 1.84 ) . Major bleeding episodes occurred in 20 patients assigned to dabigatran ( 1.6 % ) and in 24 patients assigned to warfarin ( 1.9 % ) ( hazard ratio with dabigatran , 0.82 ; 95 % CI , 0.45 to 1.48 ) , and episodes of any bleeding were observed in 205 patients assigned to dabigatran ( 16.1 % ) and 277 patients assigned to warfarin ( 21.9 % ; hazard ratio with dabigatran , 0.71 ; 95 % CI , 0.59 to 0.85 ) . The numbers of deaths , acute coronary syndromes , and abnormal liver-function tests were similar in the two groups . Adverse events leading to discontinuation of the study drug occurred in 9.0 % of patients assigned to dabigatran and in 6.8 % of patients assigned to warfarin ( P=0.05 ) . CONCLUSIONS For the treatment of acute venous thromboembolism , a fixed dose of dabigatran is as effective as warfarin , has a safety profile that is similar to that of warfarin , and does not require laboratory monitoring . ( Clinical Trials.gov number , NCT00291330 . BACKGROUND Warfarin is very effective in preventing recurrent venous thromboembolism but is also associated with a substantial risk of bleeding . After three months of conventional warfarin therapy , a lower dose of anticoagulant medication may result in less bleeding and still prevent recurrent venous thromboembolism . METHODS We conducted a r and omized , double-blind study , in which 738 patients who had completed three or more months of warfarin therapy for unprovoked venous thromboembolism were r and omly assigned to continue  warfarin therapy with a target international normalized ratio ( INR ) of 2.0 to 3.0 ( conventional intensity ) or a target INR of 1.5 to 1.9 ( low intensity ) . Patients were followed for an average of 2.4 years . RESULTS Of 369 patients assigned to low-intensity therapy , 16 had recurrent venous thromboembolism ( 1.9 per 100 person-years ) , as compared with 6 of 369 assigned to conventional-intensity therapy ( 0.7 per 100 person-years ; hazard ratio , 2.8 ; 95 percent confidence interval , 1.1 to 7.0 ) . A major bleeding episode occurred in nine patients assigned to low-intensity therapy ( 1.1 events per 100 person-years ) and eight patients assigned to conventional-intensity therapy ( 0.9 event per 100 person-years ; hazard ratio , 1.2 ; 95 percent confidence interval , 0.4 to 3.0 ) . There was no significant difference in the frequency of overall bleeding between the two groups ( hazard ratio , 1.3 ; 95 percent confidence interval , 0.8 to 2.1 ) . CONCLUSIONS Conventional-intensity warfarin therapy is more effective than low-intensity warfarin therapy for the long-term prevention of recurrent venous thromboembolism . The low-intensity warfarin regimen does not reduce the risk of clinical ly important bleeding BACKGROUND Anticoagulation is recommended as st and ard of care for venous thromboembolism ( VTE ) ( pulmonary embolism [PE]/deep vein thrombosis [ DVT ] ) , for which unfractionated heparin ( UFH ) and warfarin are used in Japan . In the multi-regional AMPLIFY study , a fixed-dose regimen of apixaban alone was non-inferior to conventional therapy for treatment of PE/DVT and was associated with significantly fewer bleeding events . METHODS AND RESULTS Japan phase 3 study ( AMPLIFY-J ) , r and omized , active-controlled , open-label study in Japanese subjects with acute PE/DVT , was design ed based on AMPLIFY . Key objectives were to investigate safety and efficacy of apixaban in symptomatic PE/DVT subjects during 24-week treatment . UFH/warfarin was used as control treatment . Apixaban was initiated at 10 mg twice daily for 7 days , followed by 5 mg twice daily for 23 weeks . All endpoints and imaging for thrombotic burden were assessed by an event adjudication committee . Eighty subjects were r and omized , 33 subjects ( 41.3 % ) were aged < 65 years .  Proportion of major/ clinical ly relevant non-major bleeding was lower in apixaban ( 7.5 % ) compared with well-controlled UFH/warfarin ( 28.2 % ; median TTR , 70.4 % ) . [ corrected ] . Recurrent VTE occurred in no subjects in apixaban and in 1 subject in UFH/warfarin .  Thrombotic burden results were similar in both groups . Proportions of subjects with adverse events was generally similar in both groups . CONCLUSIONS Apixaban was well-tolerated and had a favorable safety profile . No clinical ly important efficacy difference compared with UFH/warfarin was observed Context The decision to discontinue anticoagulation for venous thromboembolism ( VTE ) should depend in part on the subsequent risk for a fatal recurrence . Previous studies have measured fatality rates in patients still receiving anticoagulant drugs .  Contribution In a cohort from 2 source studies that had monitored 2052 patients for an average of 4.5 years after discontinuing anticoagulation for a first episode of VTE , the annual risk for any fatal pulmonary embolism ( PE ) 
    Output:
    
Evidence is currently insufficient to permit definitive conclusions concerning the effectiveness and safety of extended thromboprophylaxis in prevention of recurrent VTE after initial oral anticoagulation therapy among participants with unprovoked VTE .