***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 
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    Input: Background and Purpose — Most r and omized controlled trials of venous thromboembolism prophylaxis have focused on reduction of deep vein thrombosis , predominantly asymptomatic deep vein thrombosis , detected on imaging . We aim ed to estimate the effects of graduated compression stockings on venous thromboembolism events , survival , and functional status at 6 months after stroke . Methods — The CLOTS Trials adopted an international multicentre , parallel group design , with central r and omization and a 1:1 treatment allocation . In CLOTS Trial 1 , 2518 immobile stroke patients were allocated thigh-length graduated compression stockings or not , and in CLOTS trial 2 , 3014 to thigh-length or below-knee graduated compression stockings . We measured vital status , Oxford H and icap Scale , and quality of life ( EQ5D-3 L ) at 6 months . Results — We compared survival in patients enrolled in Trials 1 and 2 with a Cox proportional hazards model , including variables included in our minimization algorithm . In both trials , allocation to thigh-length graduated compression stockings was associated with a very slight , but nonsignificant , increased hazard of death in the first 6 months ( Trial 1 : hazard ratio , 1.087 ; 95 % confidence interval , 0.913–1.295 ; and Trial 2 : hazard ratio , 1.037 ; 95 % confidence interval , 0.892–1.205 ) . There were no statistically significant differences in venous thromboembolism events , Oxford H and icap Scale , or EQ5D-3 L between the treatment groups in CLOTS Trials 1 or 2 . Conclusions — Although underpowered to detect clinical ly important effects on long-term outcomes , our results effectively exclude a > 10 % relative reduction in the hazard of death within 6 months associated with the use of thigh-length stockings . No other long-term benefits were apparent Introduction Post-thrombotic syndrome ( PTS ) is a serious complication of deep vein thrombosis ( DVT ) of the leg that affects 20–50 % of patients . Once a patient experiences PTS there is no treatment that effectively reduces the debilitating complaints . Two r and omised controlled trials showed that elastic compression stocking ( ECS ) therapy after DVT for 24 months can reduce the incidence of PTS by 50 % . However , it is unclear whether all patients benefit to the same extent from ECS therapy or what the optimal duration of therapy for individual patients should be . ECS therapy is costly , inconvenient , dem and ing and sometimes even debilitating . Tailoring therapy to individual needs could save substantial costs . The objective of the IDEAL DVT study , therefore , is to evaluate whether tailoring the duration of ECS therapy on signs and symptoms of the individual patient is a safe and effective method to prevent PTS , compared with st and ard ECS therapy . Methods and analysis A multicentre , single-blinded , allocation concealed , r and omised , non-inferiority trial . A total of 864 consecutive patients with acute objective ly documented proximal DVT of the leg are r and omised to either st and ard duration of 24 months or tailored duration of ECS therapy following an initial therapeutic period of 6 months . Signs and symptoms of PTS are recorded at regular clinic visits . Furthermore , quality of life , costs , patient preferences and compliance are measured . The primary outcome is the proportion of patients with PTS at 24 months . Ethics and dissemination Based on current knowledge the st and ard application of ECS therapy is question ed . The IDEAL DVT study will address the central questions that remain unanswered : Which individual patients benefit from ECS therapy and what is the optimal individual treatment duration ? Primary ethics approval was received from the Maastricht University Medical Centre . Results Results of the study will be disseminated via peer- review ed publications and presentations at scientific conferences . Trial registration number NCT01429714 and NTR 2597 Acute deep venous thrombosis ( DVT ) causes leg pain .  Elastic compression stockings ( ECS ) have potential to relieve DVT-related leg pain by diminishing the diameter of distended veins and increasing venous blood flow . It was our objective to determine whether ECS reduce leg pain in patients with acute DVT . We performed a secondary analysis of the SOX Trial , a multicentre r and omised placebo controlled trial of active ECS versus placebo ECS to prevent the post-thrombotic syndrome . The study was performed in 24 hospital centres in Canada and the U.S. and included 803 patients with a first episode of acute proximal DVT . Patients were r and omised to receive active ECS ( knee length , 30 - 40 mm Hg graduated pressure ) or placebo ECS ( manufactured to look identical to active ECS , but lacking therapeutic compression ) . Study outcome was leg pain severity assessed on an 11-point numerical pain rating scale ( 0 , no pain ; 10 , worst possible pain ) at baseline , 14 , 30 and 60 days after r and omisation . Mean age was 55 years and 60 % were male . In active ECS patients ( n=409 ) , mean ( SD ) pain severity at baseline and at 60 days were 5.18 ( 3.29 ) and 1.39 ( 2.19 ) , respectively , and in placebo ECS patients ( n=394 ) were 5.38 ( 3.29 ) and 1.13 ( 1.86 ) , respectively . There were no significant differences in pain scores between groups at any assessment point , and no evidence for subgroup interaction by age , sex or anatomical extent of DVT . Results were similar in an analysis restricted to patients who reported wearing stockings every day . In conclusion , ECS do not reduce leg pain in patients with acute proximal DVT Objective The purpose of this r and omized study was to evaluate the influence of immediate multilayer compression b and ages before application of elastic stockings in the acute phase of deep-vein thrombosis ( DVT ) on development of the post-thrombotic syndrome ( PTS ) . Methods Sixty-nine patients with acute symptomatic DVT were r and omized to immediate b and aging ( n = 34 ) or no b and aging ( n = 35 ) . After reduction of edema sized-to-fit elastic stockings were applied in all patients after 7–14 days . Follow-up visits and non-invasive examinations were planned after 7 , 30 and 90 days and 1 year . Venous outflow resistance ( VOR ) was measured by strain gauge plethysmography . Thrombosis score ( TS ) and reflux were measured by duplex scanning . After one year patients were evaluated for clinical PTS using both the clinical scale of the CEAP classification and the Villalta score . Results Improvement of clinical symptoms and decrease of leg circumference was better on day 7 in the b and aging group , but after 1 and 3 months clinical symptoms had improved equally in both groups . In 7 patients in the no-b and aging group a b and age was applied after all because of persistent edema after 10 days . There were no differences in VOR , TS and reflux . Using the CEAP classification the incidence of PTS was 39 % in patients with b and ages and 42 % in patients without b and ages ( RR 0.91 , 95 % CI 0.50–1.66 ) . Using the Villalta score the incidence of PTS was resp . 29 and 33 % ( RR 0.87 , 95 % CI 0.41–1.8 ) . There was no difference in severity of PTS . Conclusion Immediate multilayer compression b and aging in the acute phase of DVT is effective in reducing edema and complaints in the first week , but has no effect on thrombus regression , valve incompetence and the development of clinical PTS after 1 year OBJECTIVE The purpose of this r and omized controlled trial was to evaluate the benefits of compression and walking exercises in comparison with bed rest in the acute stage of proximal deep venous thrombosis ( DVT ) . METHODS Forty-five patients with proximal DVT that was proved with compression ultrasound scan or phlebography were r and omized into three groups . Group A consisted of 15 patients who received  inelastic compression b and ages ( Unna boots on the lower leg , adhesive b and ages on the thigh ) , and group B consisted of 15 patients who received thigh-length compression stockings , class II . Group C consisted of 15 patients who underwent bed rest and no compression . All patients received dalteparin , 200 IU/kg per body weight , subcutaneously every 24 hours . The clinical characteristics of the three groups were comparable . Primary end points were the reduction of pain assessed daily with the Visual Analogue Scale and the Lowenberg test , the reduction of leg circumference at the ankle and calf levels , and the improvement of clinical scores . The daily walking distance was measured with a pedometer . Safety parameters were ventilation-perfusion scans and duplex ultrasound scans performed on days 0 and 9 . RESULTS The daily walking distance was between 600 and 12,000 m in the compression groups and averaged 66 m in the bed rest group . The pain level showed a statistically significant reduction starting after the second day in the compression groups ( A and B ) and after 9 days in the bed rest group C ( P < .05 ) . The same was true for the measurement of leg circumference . Improvement of the clinical scores was significantly better in the compression groups compared with the bed rest group ( P < .01 ) . There was no significant difference concerning the occurrence of new pulmonary emboli and regression of thrombus diameter . Progression of thrombi in the femoral vein was greater and occurred more frequently in the bed rest group than in the other two groups ( P = not significant ) . CONCLUSION Mobile patients with acute proximal DVT treated with low molecular weight heparin should be encouraged to walk with compression b and ages or medical compression stockings . The rate of resolution of pain and swelling is significantly faster when the patient ambulates with compression . The risk of pulmonary embolism is not significantly increased by this approach BACKGROUND Post-thrombotic syndrome varies from mild oedema to incapacitating swelling with pain and ulceration . We investigated the rate of post-thrombotic syndrome after a first episode of deep-vein thrombosis and assessed the preventive effect of direct application of a sized-to-fit grade d compression stocking . METHODS Patients with a first episode of venogram-proven proximal deep-vein thrombosis were r and omly assigned no stockings ( the control group ) or made-to-measure grade d compression elastic stockings for at least 2 years . Post-thrombotic syndrome was assessed with a st and ard scoring system that combined clinical characteristics and objective leg measurements . Patients were assessed every 3 months during the first 2 years , and every 6 months thereafter for at least 5 years . The cumulative incidence of mild-to-moderate post-thrombotic syndrome was the primary outcome measure . FINDINGS Of the 315 consecutive out patients considered for inclusion , 44 were excluded and 77 did not consent to take part . 194 patients were r and omly assigned compression stockings ( n = 96 ) or no stockings ( n = 98 ) . The median follow-up was 76 months ( range 60 - 96 ) in both groups . Mild-to-moderate post-thrombotic syndrome ( score > or = 3 plus one clinical sign ) occurred in 19 ( 20 % ) patients in the stocking group and in 46 ( 47 % ) control-group patients ( p < 0.001 ) . 11 ( 11 % ) patients in the stocking group developed severe post-thrombotic syndrome ( score > or = 4 ) , compared with 23 ( 23 % ) patients in the control group ( p < 0.001 ) . In both groups , most cases of post-thrombotic syndrome occurred within 24 months of the acute thrombotic event . INTERPRETATION About 60 % of patients with a first episode of proximal deep-vein thrombosis develop post-thrombotic syndrome within 2 years . A sized-to-fit compression stocking reduced this rate by about 50 % It is a common tradition to admit patients with deep vein thrombosis ( DVT ) to the hospital and put them to bed for several days because of fear from pulmonary embolism , even if they are mobile . Between May 1994 and December 1997 929 patients were admitted to our department who were treated by subcutaneous injections of low-molecular-weight heparin ( mainly 200 IU dalteparin per kilogram body-weight per 24 hours ) , got firm compression b and ages and were encouraged to walk as much as possible . On admission DVT propagated into the pelvis in 268 patients , into the thigh in 480 and below the popliteal level in 181 patients .  V/Q-lung scans  were performed at baseline and repeated after 10 days on average . In these three groups primary pulmonary embolism was diagnosed in 49.4 % , 50 % and 34 % respectively , new emboli after 10 days were found in 6.1 % , 5.7 % and 3.9 % . Only one third of the patients with embolism on admission and 5 from 50 patients who developed new emboli showed some dyspnoea . 12 patients died and underwent autopsy , 3 fatal events were caused by pulmonary embolism . With out management the incidence of thromboembolic complications is statistically significantly lower than data from the literature . Preliminary results from an ongoing r and omised trial comparing bed-rest , compression b and ages and compression stockings in the acute phase of proximal DVT demonstrate faster improvement of swelling and of pain in the compression- 
    Output:
    
Compliance with wearing of compression stockings was generally high but varied across studies .
Low- quality evidence suggests that elastic compression stockings may reduce the occurrence of PTS after DVT .