***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: BACKGROUND Patients with acute proximal deep-vein thrombosis are usually treated first in the hospital with intravenous st and ard ( unfractionated ) heparin . However , the longer plasma half-life , better bioavailability after subcutaneous administration , and more predictable anticoagulant response of low-molecular-weight heparins make them attractive for possible home use . We compared these two approaches . METHODS Patients with acute proximal deep-vein thrombosis were r and omly assigned to receive either intravenous st and ard heparin in the hospital ( 253 patients ) or low-molecular-weight heparin ( 1 mg of enoxaparin per kilogram of body weight subcutaneously twice daily ) administered primarily at home ( 247 patients ) . The study design allowed out patients taking low-molecular-weight heparin  to go home immediately and hospitalized patients taking low-molecular-weight heparin to be discharged early . All the patients received warfarin starting on the second day . RESULTS Thirteen of the 247 patients receiving low-molecular-weight heparin  ( 5.3 percent ) had recurrent thromboembolism , as compared with 17 of the 253 patients receiving st and ard heparin ( 6.7 percent ; P=0.57 ; absolute difference , 1.4 percentage points ; 95 percent confidence interval , -3.0 to 5.7 ) . Five patients receiving low-molecular-weight heparin had major bleeding , as compared with three patients receiving st and ard heparin . After r and omization , the patients who received low-molecular-weight heparin spent a mean of 1.1 days in the hospital , as compared with 6.5 days for the st and ard-heparin group ; 120 patients in the low-molecular-weight- heparin group did not need to be hospitalized at all . CONCLUSIONS Low-molecular-weight heparin can be used safely and effectively to treat patients with proximal deep-vein thrombosis at home Subcutaneous body weight-adjusted low molecular weight heparin ( LMWH ) has been proven as effective and safe as intravenous aPTT-adjusted unfractionated heparin ( UFH ) for the treatment of patients with acute deep venous thrombosis ( DVT ) . In this study we evaluate the efficacy of the initial treatment of proximal DVT with a fixed-dose , body weight-independent application of the LMWH Certoparin with a six month follow-up . In a prospect i ve , multicentre , r and omized , active-controlled study 1220 patients with objective ly diagnosed proximal DVT were r and omly assigned to subcutaneous 8000 U anti-factor Xa of Certoparin twice daily for 10 to 14 days or intravenous aPTT-adjusted UFH for 5 to 8 days . Both regimen were followed by oral anticoagulation for 6 months . The primary end point was the rate of symptomatic and objective ly confirmed thromboembolic events within 6 months . The aim of the study was to demonstrate the non-inferiority of the Certoparin regimen as compared to UFH . The per- protocol analysis revealed 22 ( 3.8 % ) thromboembolic events in the Certoparin group and 24 ( 4.3 % ) in patients assigned to UFH within 6 months , thereby proving the non-inferiority ( p<0.01 ) , confirmed by intent-to-treat analysis ( p<0.001 ) . Major bleeding occurred in 6 and 7 patients started on Certoparin or UFH during the treatment period . Thromboembolic events were equally distributed in body weight categories with < 50 , 50 - 80 and > 80 kg as followed : 0 , 3.6 % and 4.1 % of patients for the Certoparin group and 0 , 4.6 % and 4.2 % of patients for the UFH group . The same was true for major bleeding complications with 0 , 2.9 % and 1.5 % for Certoparin and 0 , 3.5 % and 4.2 % for UFH .  Overall mortality was 1.9 % in the Certoparin group and 2.7 % in the UFH group . Fixed-dose body weight-independent subcutaneous LMWH Certoparin is at least as efficacious and safe as intravenous aPTT-adjusted UFH for the initial treatment of acute proximal DVT . This effect is maintained during a 6-months follow-up of treatment with oral anticoagulation INTRODUCTION Trials comparing the use of full dose unfractionated heparin ( UFH ) or low molecular weight heparins ( LMWHs ) in very elderly patients with impaired renal function are lacking . IRIS aim ed to assess whether LMWH is at least as safe as UFH in this population . MATERIAL S AND METHODS The study included renally impaired patients ≥70 years with acute symptomatic lower limb deep vein thrombosis ( DVT ) . Patients were r and omized to initial treatment with either tinzaparin 175 IU/kg once daily ( n=269 ) or activated partial thromboplastin time-adjusted UFH twice daily ( n=270 ) . After acute management both groups received vitamin K antagonist to day 90 . RESULTS The trial was stopped prematurely due to a difference in mortality favoring the UFH group ( 11.5 vs. 6.3 % ; p=0.035 ) . Rates of clinical ly relevant bleedings by day 90 were similar in the tinzaparin ( 11.9 % ) and UFH ( 11.9 % ) groups , as were rates of confirmed recurrent venous thromboembolism ( VTE ) ( 2.6 vs. 1.1 % ; p=0.34 ) . As the mortality difference could not be explained by bleedings or recurrent VTE , a post-hoc analysis was performed . This identified six baseline characteristics significantly correlated with mortality , of which five were over-represented in the tinzaparin group . CONCLUSION The IRIS study was a challenging study involving patients ( mean age 83 years ) usually excluded from clinical studies , but its early termination has left questions unanswered . The mortality difference observed with tinzaparin vs. UFH in elderly , renally-impaired patients with DVT can not be explained on the basis of bleedings or recurrent VTE , and may reflect an imbalance of mortality risk factors at baseline Intravenous heparin followed by oral anticoagulant therapy ( e. g. with coumarin ) is still the most widely used treatment for  deep venous thromboembolism .  Self-administered subcutaneous injections of heparin have been thought of as a promising alternative to coumarin , but the high doses required for ongoing prophylaxis have raised concerns about the possible development of bone disease . Certainly , long-term heparin therapy has been reported to cause osteoporosis in both laboratory animals and humans . This study aim ed to compare the efficacy and safety of unfractionated ( UF ) heparin with that of a low molecular weight heparin ( Fragmin , Kabi Pharmacia ) in the prevention of recurrent deep venous thrombosis ( DVT ) and pulmonary embolism ( PE ) in a consecutive series of patients with contraindications to coumarin therapy . The patients comprised 40 men and 40 women , aged between 19 and 92 years ( mean age , 68 years ) . They had all previously been diagnosed as having acute DVT and had been treated with conventional doses of heparin while in hospital . All patients had at least one of the following conditions : recent blood loss ( either spontaneous or during admission while receiving heparin therapy ) ; active gastroduodenal ulcer disease ; psychological or physical inability or unwillingness to underst and and accept the need for regular laboratory monitoring during coumarin treatment ; chronic alcoholism ; dementia ; pregnancy ; recent neurosurgery , and pericardial effusion ; or were over 80 years of age . They were r and omly allocated to receive either UF heparin , 10,000 IU s.c . b.d . , or Fragmin , 5000 IU anti-Factor Xa s.c . b.d . , for a period of 3 - 6 months . ( ABSTRACT TRUNCATED AT 250 WORDS BACKGROUND Body weight-adjusted subcutaneous low-molecular-weight heparin ( LMWH ) has been proven to be at least as effective and safe as dose-adjusted intravenous unfractionated heparin ( UFH ) for the treatment of patients with venous thromboembolism . However , body weight-adjusted dosage of low-molecular-weight heparin may be cumbersome and could lead possibly to incorrect dosing . Therefore a fixed LMWH dose , independent of body-weight , might rationalize initial treatment for venous thromboembolism . METHODS Patients with proven proximal deep-vein thrombosis were r and omly assigned to fixed dose subcutaneous LMWH Certoparin ( 8,000 anti-factor Xa U b.i.d . ; 265 patients ) or to adjusted dose i.v . UFH ( 273 patients ) for 12 days . Vitamin K antagonists were started between day 3 and 7 and continued for up to 6 months . The primary outcome measure was a 30 percent or greater improvement in the Marder Score , as revealed by repeated venography on day 12 ( end of the initial treatment ) . The secondary composite outcome measure included death , recurrent venous thromboembolism and major bleeding and was assessed at day 12 and after 6 months by a blinded adjunction committee . RESULTS The Marder score improved by 30 % or more in 30.3 % and 25.0 % of patients assigned to LMWH ( 198 paired venograms ) and UFH ( 192 paired venograms ) , respectively ( 2p = 0.26 ) . At the end of the initial treatment , the composite outcome was observed in 4 of the 265 patients ( 1.5 % ) r and omized to LMWH , as compared with 14 of the 273 patients ( 5.1 % ) r and omized to UFH ( 2p = 0.03 ) . At 6 months these figures were 6.8 % and 12.8 % , respectively ( risk reduction 0.53 , confidence interval 0.31 - 0.90 , 2p = 0.02 ) . CONCLUSION Fixed dose subcutaneous LMWH certoparin is at least as efficacious as UFH in resolving proximal vein thrombosis We performed a prospect i ve , r and omized , double-blind trial in 194 unselected patients to determine the safety and efficacy of low molecular weight heparin ( Fragmin ) compared with st and ard heparin as the initial treatment of acute venous thromboembolism . Ninety-eight patients received continuous intravenous heparin  , and 96 patients received Fragmin for 5 - 10 days . Doses were adjusted to maintain anti-Xa levels between 0.3 and 0.6 unit/ml for patients with a high risk for a bleeding complication and between 0.4 and 0.9 unit/ml for patients with a low risk for bleeding . Treatment was stopped when a therapeutic level of anticoagulation ( International Normalized Ratio greater than 3.5 ) was reached with coumarins . Thirteen patients in the heparin group and 10 patients in the Fragmin group had a major bleeding complication . The incidence of major and minor bleeding complications combined decreased from 48.9 % to 38.5 % ( 95 % confidence interval for the difference , -3.5 % to + 24.2 % ) , corresponding with a relative bleeding risk reduction of 21.2 % . There were no significant differences in efficacy as defined by new high-probability defects on repeat ventilation-perfusion scintigraphy of the lung in 80 patients : six of 46 patients in the heparin group and 3 of 34 patients in the Fragmin group had new defects ( 95 % confidence interval for the difference , -9.4 % to + 17.8 % ) . We conclude that low molecular weight heparin ( Fragmin ) given in adjusted , continuous , and intravenous doses is safe and effective as initial treatment of acute venous thromboembolism compared with heparin . There is a trend in risk reduction for bleeding in favor of low molecular weight heparin , a trend , however , that is smaller than expected compared with animal studies BACKGROUND An intravenous course of st and ard ( unfractionated ) heparin with the dose adjusted to prolong the activated partial-thromboplastin time to a desired length is the st and ard initial in-hospital treatment for patients with deep-vein thrombosis , but fixed-dose subcutaneous low-molecular-weight heparin appears to be as effective and safe . Because the latter treatment can be given on an outpatient basis , we compared the two treatments in symptomatic out patients with proximal-vein thrombosis but no signs of pulmonary embolism . METHODS We r and omly assigned patients to adjusted-dose intravenous st and ard heparin administered in the hospital ( 198 patients ) or fixed-dose subcutaneous low-molecular-weight heparin administered at home , when feasible ( 202 patients ) . We compared the treatments with respect to recurrent venous thromboembolism , major bleeding , quality of life , and costs . RESULTS Seventeen of the 198 patients who received st and ard heparin ( 8.6 percent ) and 1 
    Output:
    
This review presents moderate- quality evidence that fixed dose LMWH reduced the incidence of recurrent thrombotic complications and occurrence of major haemorrhage during initial treatment ; and low- quality evidence that fixed dose LMWH reduced thrombus size when compared to UFH for the initial treatment of VTE .
There was no difference in overall mortality between participants treated with LMWH and those treated with UFH ( moderate- quality evidence ) .