***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: OBJECTIVE To assess the efficacy of endovascular aneurysm repair ( EVAR ) against st and ard alternative management in patients with large abdominal aortic aneurysm ( AAA ) . DESIGN Two national , multicentre r and omised trials - EVAR trials 1 and 2 . SETTING Patients were recruited from 38 out of 41 eligible UK hospitals . PARTICIPANTS Men and women aged at least 60 years , with an AAA measuring at least 5.5 cm on a computerised tomography scan that was regarded as anatomically suitable for EVAR , were assessed for fitness for open repair . Patients considered fit were r and omised to EVAR or open repair in EVAR trial 1 and patients considered unfit were r and omised to EVAR or no intervention in EVAR trial 2 . INTERVENTIONS EVAR , open repair or no intervention . MAIN OUTCOME MEASURES The primary outcome was mortality ( operative , all-cause and AAA related ) . Patients were flagged at the UK Office for National Statistics with central ly coded death certificates assessed by an Endpoints Committee . Power calculations based upon mortality indicated that 900 and 280 patients were required for EVAR trials 1 and 2 , respectively . Secondary outcomes were graft-related complications and re interventions , adverse events , renal function , health-related quality of life and costs . Cost-effectiveness analyses were performed for both trials . RESULTS Recruitment occurred between 1 September 1999 and 31 August 2004 , with targets exceeded in both trials : 1252 r and omised into EVAR trial 1 ( 626 to EVAR ) and 404 r and omised into EVAR trial 2 ( 197 to EVAR ) . Follow-up closed in December 2009 with very little loss to follow-up ( 1 % ) . In EVAR trial 1 , 30-day operative mortalities were 1.8 % and 4.3 % in the EVAR and open-repair groups , respectively : adjusted odds ratio 0.39 [ 95 % confidence interval ( CI ) 0.18 to 0.87 ] , p = 0.02 . During a total of 6904 person-years of follow-up , 524 deaths occurred ( 76 AAA related ) . Overall , there was no significant difference between the groups in terms of all-cause mortality : adjusted hazard ratio ( HR ) 1.03 ( 95 % CI 0.86 to 1.23 ) , p = 0.72 . The EVAR group did demonstrate an early advantage in terms of AAA-related mortality , which was sustained for the first few years , but lost by the end of the study , primarily due to fatal endograft ruptures : adjusted HR 0.92 ( 95 % CI 0.57 to 1.49 ) , p = 0.73 . The EVAR procedure was more expensive than open repair ( mean difference £ 1177 ) and not found to be cost-effective , but the model was sensitive to alternative assumptions . In EVAR trial 2 , during a total of 1413 person-years of follow-up , a total of 305 deaths occurred ( 78 AAA related ) . The 30-day operative mortality was 7.3 % in the EVAR group . However , this group later demonstrated a significant advantage in terms of AAA-related mortality , but this became apparent only after 4 years : overall adjusted HR 0.53 ( 95 % CI 0.32 to 0.89 ) , p = 0.02 . Sadly , this advantage did not result in any benefit in terms of all-cause mortality : adjusted HR 0.99 ( 95 % CI 0.78 to 1.27 ) , p = 0.97 . Overall , EVAR was more expensive than no intervention ( mean difference £ 10,222 ) and not found to be cost-effective . CONCLUSIONS EVAR offers a clear operative mortality benefit over open repair in patients fit for both procedures , but this early benefit is not translated into a long-term survival advantage . Among patients unfit for open repair  , EVAR is associated with a significant long-term reduction in AAA-related mortality but this does not appear to influence all-cause mortality . TRIAL REGISTRATION Current Controlled Trials IS RCT N 55703451 . FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol . 16 , No. 9 . See the HTA programme website for further project information BACKGROUND The Positive Impact of EndoVascular Options for Treating Aneurysms Early ( PIVOTAL ) trial enrolled individuals with small ( 4.0- to 5.0-cm diameter ) abdominal aortic aneurysms ( AAA ) and reported no difference in rupture or aneurysm-related death for patients who received early endovascular repair ( EVAR ) vs surveillance with serial imaging studies .  We evaluated re source use , medical cost , and quality of life outcomes associated with the PIVOTAL treatment strategies . METHODS This prospect i ve economic and quality of life study was conducted within a r and omized trial , with PIVOTAL sites participating in the quality of life ( n = 67 ) and economic ( n = 63 ) studies . The PIVOTAL trial r and omized 728 patients ( 366 early EVAR and 362 surveillance ) . We used information from 701 quality of life ( 351 early EVAR and 350 surveillance ) and 614 economic ( 314 early EVAR and 300 surveillance ) study participants enrolled in the PIVOTAL trial . The main outcome measures were total medical costs and the aneurysm repair rate at 48 months . RESULTS After 6 months , the rate of aneurysm repair was 96 vs 10 per 100 patients in the early EVAR and surveillance groups , respectively ( difference , 86 ; 95 % confidence interval [ CI ] , 82 - 90 ; P < .0001 ) , and total medical costs were greater in the early EVAR group ( $ 33,471 vs $ 5520 ; difference , $ 27,951 ; 95 % CI , $ 25,156-$30,746 ; P < .0001 ) . In months 7 through 48 , however , the rate of aneurysm repair was 54 per 100 patients in the surveillance group , and total medical costs were higher for patients in the surveillance vs the early EVAR group ( $ 40,592 vs $ 15,197 ; difference , $ 25,394 ; 95 % CI , $ 15,184-$35,605 ; P < .0001 ) . At 48 months ' follow-up , early EVAR patients had greater cumulative use of AAA repair ( 97 vs 64 per 100 patients ; difference , 34 ; 95 % CI , 21 - 46 ; P < .0001 ) , but there was no difference in total medical costs ( $ 48,669 vs $ 46,112 ; difference , $ 2557 ; 95 % CI , -$8043 to $ 13,156 ; P = .64 ) . After discounting at 3 % per annum , total medical costs for early EVAR and surveillance patients remained similar ( $ 47,765 vs $ 43,532 ; difference , 4232 ; 95 % CI , -$5561 to $ 14,025 ; P = .40 ) . There were no treatment-related differences in quality of life at 24 months . CONCLUSIONS A treatment strategy involving early repair of smaller AAA with EVAR is associated with no difference in total medical costs at 48 months vs surveillance with serial imaging studies . Longer follow-up is required to determine whether the late medical cost increases observed for surveillance will persist beyond 48 months OBJECTIVE This study was conducted to determine the costs and comparative cost-effectiveness of two methods of  abdominal aortic aneurysm ( AAA ) repair in the Open Versus Endovascular Repair ( OVER ) Veterans Affairs ( VA ) Cooperative Study , a multicenter r and omized trial of 881 patients . METHODS The primary outcomes of this analysis were mean total health care cost per life-year and per quality -adjusted life-year ( QALY ) from r and omization to 2 years after . QALYs were calculated from EuroQol (EQ)-5D question naires collected at baseline and annually . Health care utilization data were obtained directly from patients and from national VA and Medicare data sources . VA costs were obtained from national VA sources using methods previously developed by the VA Health Economics Re source Center . Costs for non-VA care were determined from Medicare cl aims data or billing data from the patient 's health care providers . RESULTS After 2 years of follow-up , mean life-years were 1.78 in the endovascular repair group and 1.74 in the open repair group ( difference , 0.04 ; 95 % confidence interval [ CI ] , -0.03 to 0.09 ; P = .29 ) . Mean QALYs were 1.462 in the endovascular group and 1.461 in the open group ( difference adjusting for baseline EQ-5D score , 0.006 ; 95 % CI , -0.038 to 0.052 ; P = .78 ) . Mean graft costs were higher in the endovascular group ( $ 14,052 vs $ 1363 ; P < .001 ) , but length of stay was shorter ( 5.0 vs 10.5 days ; P < .001 ) , result ing in a lower mean cost of the hospital admission for the AAA procedure in the endovascular repair group of $ 37,068 vs $ 42,970 ( difference , -$5901 ; 95 % CI , -$12,135 to -$821 ; P = .04 ) . After 2 years , total health care costs remained lower in the endovascular group , but the difference was no longer significant ( -$5019 ; 95 % CI , -$16,720 to $ 4928 ; P = .35 ) . The probability of endovascular repair being less costly and more effective was 70.9 % for life-years and 51.4 % for QALYs . CONCLUSIONS In this multicenter r and omized trial , endovascular AAA repair result ed in lower cost and better survival than open repair after the initial hospitalization for repair ; but after 2 years , survival , quality of life , and costs were not significantly different between the two treatments Objective To assess the cost effectiveness of screening  men aged 65 for abdominal aortic aneurysm . Design Cost effectiveness analysis based on a probabilistic , enhanced economic decision analytical model from screening to death . Population and setting Hypothetical population of men aged 65 invited ( or not invited ) for ultrasound screening in the Danish healthcare system . Data sources Published results from r and omised trials and observational epidemiological studies retrieved from electronic bibliographic data bases , and supplementary data obtained from the Danish Vascular Registry . Data synthesis A hybrid decision tree and Markov model was developed to simulate the short term and long term effects of screening for abdominal aortic aneurysm compared with no systematic screening on clinical and cost effectiveness outcomes . Probabilistic sensitivity analyses using Monte Carlo simulation were carried out . Results were presented in a cost effectiveness acceptability curve , an expected value of perfect information curve , and a curve showing the expected ( net ) number of avoided deaths from abdominal aortic aneurysm over time after the introduction of screening . The model was vali date d by calibrating base case health outcomes and expected activity levels against evidence from the recent Cochrane review of screening for abdominal aortic aneurysm . Results The estimated costs per quality adjusted life year ( QALY ) gained discounted at 3 % per year over a lifetime for costs and QALYs was £ 43 485 ( € 54 852 ; $ 71 160 ) . At a willingness to pay threshold of £ 30 000 the probability of screening for abdominal aortic aneurysm being cost effective was less than 30 % . One way sensitivity analyses showed the incremental cost effectiveness ratio varying from £ 32 640 to £ 66 001 per QALY . Conclusion Screening for abdominal aortic aneurysm does not seem to be cost effective . Further research is needed on long term quality of life outcomes and costs The Glasgow Aneurysm Score ( GAS ) , developed and published by the same authors , is a clinical prognostic scoring system that predicts mortality when operating on either intact or ruptured abdominal aortic aneurysms ( AAA ) taking into account these clinical criteria : patient 's age , shock at presentation , myocardial disease , cerebrovascular disease and renal disease . The GAS was prospect ively evaluated by study ing 320 consecutive patients with AAA who were operated on at Glasgow , Aberdeen and Inverness , Scotl and , in the period between January 1990 and May 1993 .  Logistic regression analysis showed very similar results to the original analysis used in developing the score . Age , shock , myocardial disease and renal disease were highly significant . Although it was not significant , cerebrovascular disease weight was not significantly different to its value in the original analysis . The mortality correlated well with the values of the score and ranged from 0 % for scores below ' 70 GAS ' to 80 % for scores over ' 95 GAS ' . The GAS appears , therefore , to be a reliable clinical predicative tool in foretelling the outcome of operating on AAA 
    Output:
    
RESULTS The analysis demonstrated it is feasible to build and run a complex clinical decision aid using DES .
The model results support current guidelines for most vignettes but suggest that earlier repair may be effective in younger , fitter patients and ongoing surveillance may be effective in elderly patients with comorbidities .
The model adds information to support decisions for patients with aneurysms outside current indications .
The economic evaluation suggests that using the ARDA compared with current guidelines could be cost-effective but there is a high level of uncertainty .
LIMITATIONS Lack of high- quality long-term data to populate all sections of the model meant that there is high uncertainty about the long-term clinical and economic consequences of repair .
The ARDA provides detailed information on the potential consequences of AAA repair or a decision not to repair that may be helpful to vascular surgeons and their patients in reaching informed decisions .