***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: The results of a multicenter , double-blind clinical trial indicate that the use of light support pantyhose significantly reduced the incidence of aches , swelling and fatigue in the lower legs of healthy women . A trend toward reduced foot and leg circumference was noted ; however , it did not correlate significantly with subjective symptomatology AIM The aim of this study was to review published literature concerning the use of compression treatments in the management of venous and lymphatic diseases and establish where reliable evidence exists to justify the use of medical compression and where further research is required to address areas of uncertainty . METHODS The authors search ed medical literature data bases and review ed their own collection s of papers , monographs and books for papers providing information about the effects of compression and r and omized clinical trials of compression devices . Papers were classified in accordance with the recommendations of the GRADE group to categorize their scientific reliability . Further classification was made according to the particular clinical problem that was addressed in the papers . The review included papers on compression stockings , b and ages and intermittent pneumatic compression devices . RESULTS The International Compression Club met once in Vienna and corresponded by email in order to reach an agreement of how the data should be interpreted . A wide range of compression levels was reported to be effective . Low levels of compression 10 - 30 mmHg applied by stockings are effective in the management of telangiectases after sclerotherapy , varicose veins in pregnancy , the prevention of edema and deep vein thrombosis ( DVT ) . High levels of compression produced by b and aging and strong compression stockings ( 30 - 40 mmHg ) are effective at healing leg ulcers and preventing progression of post-thrombotic syndrome as well as in the management of lymphedema . In some areas no reliable evidence was available to permit recommendations of level of compression or duration of treatment . These included : management of varicose veins to prevent progression , following surgical treatment or sclerotherapy for varicose veins , and the level of compression required to treat acute DVT . CONCLUSION This review shows that whilst good evidence for the use of compression is available in some clinical indications , there is much still to be discovered . Little is know about dosimetry in compression , for how long and at what level compression should be applied . The differing effects of elastic and short-stretch compression are also little understood QUESTIONS UNDER STUDY To determine the efficacy of compression stockings in preventing  emergent varicose veins in pregnancy . METHODS A prospect i ve r and omised controlled study in the outpatient department of the University Hospital of Zurich , Switzerl and , including women with uncomplicated pregnancies < 12 weeks at outset of study . A  no-stockings control group ( n = 15 ) was compared with two treatment groups : group 1 ( n = 12 ) wore compression class I stockings ( 18 - 21 mm Hg ) on the left leg and class II stockings ( 25 - 32 mm Hg ) on the right ; in group 2 ( n = 15 ) , the compression classes were reversed . Stockings were worn from study entry to term . Endpoints were emergence and worsening of superficial varicose veins , long saphenous vein reflux at the sapheno-femoral junction , and leg symptoms ( pain , discomfort , cramps ) during pregnancy . RESULTS Both classes of compression stockings failed to prevent the emergence of superficial varicose veins . However , long saphenous vein reflux at the sapheno-femoral junction was observed in the third trimester in only 1/27 treated women vs. 4/15 controls ( p = 0.047 ) ; in addition , more treated women reported improved leg symptoms ( 7/27 vs. 0/15 controls ; p = 0.045 ) . Emergent varicose changes , however , did not differ significantly ( 7/14 controls vs. 5/12 in group 1 and 8/14 in group 2 ; 3x3 table , Fisher 's exact = 0.94 ) . CONCLUSIONS Although compression stockings do not prevent the emergence of gestational varicose veins , they significantly decrease the incidence of long saphenous vein reflux at the sapheno-femoral junction and improve leg symptoms . Our results also suggest that superficial varices and deep venous insufficiency may have a different aetiology Compression garments for the lower limb were tested in two groups -- general support garments and anti-embolism supports .  A total of 98 patients was examined . The method used was by the interposition of partly fluid-filled pressure sensors between garment and skin . A combination of roller b and age with shaped tubigrip ( SBB -- Seton ) and Sigvaris stockings afforded effective pressure in the general support group but only the roller b and age plus pressure garment ( Seton ) did so in the anti-embolism group , both in the acute and prolonged studies HYPOTHESIS Surgical compression stockings measurably improve venous physiologic mechanisms , and stocking br and s do not differ from one another . METHODS Eleven patients , ( 8 men and 3 women [ mean age , 53 years ] ) , were included . Six patients had primary venous insufficiency and 5 patients had secondary venous insufficiency ; 5 patients were in CEAP class 4 and 6 were in CEAP class 5 . Patients were r and omly assigned to a sequence of 4 br and s of knee-high , open-toe , 30- to 40-mm Hg stockings . Each patient wore a stocking for a 1-month equilibration period , then a different stocking monthly for 4 months in a row .  Air plethysmography examinations  were performed with and without stockings before and after each month of wear . Patients filled out a daily stocking record log and a monthly satisfaction survey . Stockings underwent compression testing after use . RESULTS Stockings controlled reflux better than they improved calf muscle pump function . With stockings on , patients in CEAP 4 benefited more than those in CEAP 5 in decreasing reflux , while patients in CEAP 5 benefited more than those in CEAP 4 in improving calf muscle pump function . Changes in residual volume fraction were improved in patients in CEAP 5 wearing stockings but not in patients in CEAP 4 . Patients with primary disease had greater volumes of reflux and calf ejection than with secondary disease . There were no hemodynamic differences between stocking br and s but there were differences in patient compliance and acceptance . CONCLUSIONS Surgical support stockings seem to be more effective in controlling reflux than in improving calf muscle pump function . All stocking br and s function equally as measured by air plethysmography The acute and long-term effect of elastic stockings has been evaluated in 20 patients ( 20 limbs ) with grade 2 venous disease . The sites of venous reflux were determined with colour flow duplex scanning . Air Plethysmography was used to measure the amount of venous reflux and the ejecting capacity of the calf muscle pump . The patients were classified in to two different groups , A and B. Both groups of patients wore elastic stockings for four weeks . In group A ( no. = 9 ) the measurements were done before , during and one day after the removal of the stockings , whereas in group B ( no. = 11 ) the last measurements were done immediately after the removal of the stockings . Patients that showed improvement in their haemodynamics were re-examined a week later . Elastic compression appeared to be beneficial in both groups . The application of the elastic stockings improved reflux and the residual volume fraction in both groups and the ejecting capacity of the calf muscle pump in group B. Immediately after the removal of the stockings ( Group B ) all the measurements regressed to the initial values with the exemption of the residual volume fraction . However , one week later , the latter also regressed to the original value . It is concluded that the beneficial effect of elastic stockings on the venous haemodynamics is present mainly when the stockings are worn . It is completely abolished within a day after their removal BACKGROUND Medical- grade compression of class I ( 20 - 30 mmHg ) and class II ( 30 - 40 mmHg ) have been shown to be beneficial against venous hypertension or congestion . Relatively few studies address the effects of ready-to-wear ( RTW ) lightweight gradient compression pantyhose on venous symptoms . OBJECTIVE To perform a study comparing the effects of two different compression RTW lightweight gradient compression stockings ( 8 - 15 mmHg and 15 - 20 mmHg ) on the venous symptoms of flight attendants . METHOD A prospect i ve crossover trial of symptom evaluation in 19 flight attendants was performed in which participants rated their symptoms on a visual analog scale . During the initial phase , participants wore no compression for 2 weeks . They then wore 8 - 15 mmHg and 15 - 20 mmHg gradient compression support hose while flying over a 4-week period . Symptoms before and after wearing the gradient compression stockings were compared and statistically analyzed . RESULTS Wearing of 8 - 15 mmHg gradient hose result ed in statistically significant improvement of discomfort ( P < 0.01 ) . Swelling , fatigue , aching , and tightness of the leg were all improved to a statistically significant degree ( P < 0.01 ) . For 15 - 20 mmHg gradient hosiery , symptoms were improved to a statistically significant or almost significant level . The difference between the 8 - 15 mmHg and 15 - 20 mmHg compression was not statistically significant . CONCLUSIONS Use of lightweight ( low compression ) RTW gradient compression hosiery is very effective in improving symptoms of discomfort ( P < 0.01 ) , swelling ( almost P < 0 . 05 ) , fatigue ( P < 0.05 ) , aching ( P < 0.01 ) , as well as leg tightness . Improvement of symptoms is statistically significant compared to no compression when hosiery was worn regularly during waking hours for 4 weeks Physical factors are known to influence hemodynamics in the veins of the lower extrem ities . In a controlled , r and omized study the authors investigated the effects of combined physical therapy on varicose veins . Over a twenty-four-week period a treatment group consisting of 12 persons exercised under the supervision of a therapist twice a week for sixty minutes . This included muscle and joint activation by means of externally applied compression and cold-temperature stimuli ( ie , thermosteresis ) . They also exercised once a day without supervision for fifteen minutes . During the same period a control group of 12 persons underwent the same measurements but no treatment . In the treatment group venous capacity decreased by an average of 16 % from 4.9 ± 0.3 ( sd ) mL/100 mL tissue to 4.1 ±0.4 ( P < 0.005 , U-test ) while in the control group it remained practically unchanged at 4.8 ±0.4 vs 5.0 ±0.3 . Venous refilling time in the lower extremities also increased in the treatment group , half refilling time rising from 7.8 ±1.0 to 11.3 ±0.9 seconds ( P < 0.001 ) and total refilling time from 17.0 ±1.4 to 25.7 ±2.1 seconds ( P < 0.001 ) ; these parameters remained virtually unchanged in the control group , with half refilling time dropping slightly from 7.7 ± 1.1 to 7.1 ± 1.3 seconds and total refilling time from 18.3 ± 1.7 to 16.3 ± 1.9 seconds . Patient self-rating scores obtained by use of a st and ardized question naire administered at baseline and at the end of week 24 improved in the treatment group only . The combined physical therapy was thus shown to be of long-term therapeutic value , improving venous function and reducing patients ' symptoms . These findings indicate that for the further development of this combined treatment regimen it would be useful to identify the individual factors contributing to its efficacy and evaluate them separately AIM The aim of this study was to compare the efficacy of Class 1 ( 10 - 15 mmHg at the ankle ) compression stockings with that of reference stockings of identical appearance during the early stages of chronic venous disease ( CVD ) . METHODS A prospect i ve multi-center r and omized double blind crossover study was conducted on 2 groups of female patients presenting with CVD with a CEAP classification of C1 - 3SEp As1 - 5 . The efficacy of Class 1 compression stockings was evaluated with respect to global painful discomfort ( visual analog scale ) , each symptom of CVD , the daily behavior of the patient , changes in the volume of the legs , and the functioning of the venous pump ( D-PPG ) . The compliance level of each patient was measured by the number of days that she wore the stockings for at least 6 hours , and tolerance was measured by the reporting of ensuing undesirable events . RESULTS A total of 125 patients were included in the study and were analyzed for intent to treat . Highly significant differences favoring Class 1 compression stockings were noted with respect to both global painful discomfort and each symptom of CVD with the exception of paresthesia . The relief of symptoms that result ed from the use of the Class 1 compression stockings was twice that which result ed from the use of the reference stockings . Differences that favored the Class 1 compression stockings were also observed with respect to 2 quality -of-life factors ( mood and daily work activity ) . Good compliance in the use of the stockings was reported for 95 % of the patients , and tolerance was higher for the Class 1 compression stockings group than for the reference group . CONCLUSION The regular wearing of Class 1 graduated elastic compression stockings during a 15-day period results in a significant improvement in the symptomatology of early-stage chronic venous disease , i.e. , in the relief of global painful discomfort as well as in quality -of-life criteria . A high level of 
    Output:
    
Wearing compression improved symptom management , but could be confounded by the exclusion of high number of non-compliant patients within the trials .
Wearing compression to slow the progression , or prevent the reoccurrence of varicose veins could not be supported by the current published evidence .
Conclusion The evidence for the benefit of compression hosiery for varicose veins was equivocal .