***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 Bleeding is the most serious complication of the use of oral anticoagulation in the prevention and treatment of thromoboembolic complications . We studied the frequency of bleeding complications in out patients treated routinely in anticoagulation clinics . METHODS In a prospect i ve cohort from thirty-four Italian anticoagulation clinics , 2745 consecutive patients were studied from the start of their oral anticoagulation ( warfarin in 64 % , acenocourmarol in the rest ) . The target anticoagulation-intensity was low ( international normalised ratio [ INR ] < or = 2.8 ) in 71 % of the patients and high ( > 2.8 ) in the remainder . We recorded demographic details and the main indication for treatment and , every 3 - 4 months , INR and outcome events . Such events included all complications ( bleeding , thrombosis , other ) , although only bleeding events are reported here , and deaths . We divided bleeding into major and minor categories . FINDINGS 43 % of the patients were women . Nearly three-fifths of the patients were aged 60 - 79 ; 8 % were over 80 . The main indication for treatment was venous thrombolism ( 33 % ) , followed by non-ischaemic heart disease ( 17 % ) . Mean follow-up was 267 days . Over 2011 patient-years of follow-up , 153 bleeding complications occurred ( 7.6 per 100 patient-years ) . 5 were fatal ( all cerebral haemorrhages , 0.25 per 100 patient-years ) , 23 were major ( 1.1 ) , and 125 were minor ( 6.2 ) . The rate of events was similar between sexes , coumarin type , size of enrolling centre , and target INR . The rate was higher in older patients : 10.5 per 100 patient-years in those aged 70 or over , 6.0 in those aged under 70 ( relative risk 1.75 , 95 % Cl 1.29 - 2.39 , p < 0.001 ) . The rate was also higher when the indication was peripheral and /or cerebrovascular disease than venous thromboembolism plus other indications ( 12.5 vs 6.0 per 100 patient-years ) ( 1.80 , 1.2 - 2.7 , p < 0.01 ) , and during the first 90 days of treatment compared with later ( 11.0 vs 6.3 , 1.75 , 1.27 - 2.44 , p < 0.001 ) . A fifth of the bleeding events occurred at low anticoagulation intensity ( INR < 2 , rate 7.7 per 100 patient-years of follow-up ) . The rates were 4.8 , 9.5 , 40.5 , and 200 at INRs 2.0 - 2.9 , 3 - 4.4 , 4.5 - 6.9 , and over 7 , respectively ( relative risks for INR > 4.5 , 7.91 , 5.44 - 11.5 , p < 0.0001 ) . INTERPRETATION We saw fewer bleeding events than those recorded in other observational and experimental studies . Oral anticoagulation has become safer in recent years , especially if monitored in anticoagulation clinics . Caution is required in elderly patients and anticoagulation intensity should be closely monitored to reduce periods of overdosing In recent years quality of life instruments have been featured as primary outcomes in many r and omized trials . One of the challenges facing the investigator using such measures is determining the significance of any differences observed , and communicating that significance to clinicians who will be applying the trial results . We have developed an approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change . Using this approach we have established a plausible range within which the minimal clinical ly important difference ( MCID ) falls . In three studies in which instruments measuring  dyspnea , fatigue , and emotional function in patients with chronic heart and lung disease were applied the MCID was represented by mean change in score of approximately 0.5 per item , when responses were presented on a seven point Likert scale . Furthermore , we have established ranges for changes in question naire scores that correspond to moderate and large changes in the domains of interest . This information will be useful in interpreting question naire scores , both in individuals and in groups of patients participating in controlled trials , and in the planning of new trials Patients who agree and those who refuse clinical trial entry may differ in attitudes towards decision control and the benefits associated with the trial arms . These differences , if they exist , have implication s for the process of obtaining informed consent and for the generalization of the results of a clinical trial . This paper describes the development and initial application of methods design ed to detect such differences . Developmental work involved creating an inventory of instruments design ed to determine patients ' attitudes towards participating in treatment decision making , permitting r and om selection of treatment , and undertaking the risks and benefits associated with the various treatments in a trial . Initial application involved modifying these instruments in terms of an actual chemotherapeutic trial for colonic adenocarcinoma , seeking responses to these measures from 60 non-eligible colorectal cancer patients , then determining whether those who would agree to trial entry differed systematic ally on these measures from those who indicated that they would refuse such a trial . Twenty-five of the respondents reported that , if faced with the actual decision , they would agree to trial entry : 35 would refuse . Refusers dem and ed more participation in decision making ( Chi-square ; P = 0.01 ) and a greater increment in treatment benefit ( t-test ; P = 0.0001 ) . Twenty-two of the 35 refusers reported aversion to r and omization as their primary reason for trial refusal . Since their particular content can be modified , these measures may be applicable to all clinical trials . They could be used to study the reasons patients accept or refuse trial entry and to determine if agreer-refuser attitude differences undermine the generalizability of a trials results CONTEXT Decision aids are tools design ed to help patients participate in the clinical decision-making process . OBJECTIVE To determine whether use of an audiobooklet ( AB ) decision aid explaining the results of a clinical trial affected the decision-making process of study participants . DESIGN R and omized controlled trial conducted from May 1997 to April 1998 . SETTING Fourteen centers that participated in the Stroke Prevention in Atrial Fibrillation ( SPAF ) III trial . PARTICIPANTS A total of 287 patients from the SPAF III aspirin cohort study , in which patients with atrial fibrillation and a relatively low risk of stroke received 325 mg/d of aspirin and were followed up for a mean of 2 years . INTERVENTION At the end of SPAF III , participants were r and omized to be informed of the study results with usual care plus use of an AB ( AB group ) vs usual care alone ( control group ) . The AB included pertinent information to help patients decide whether to continue taking aspirin or switch to warfarin . MAIN OUTCOME MEASURES Patients ' ability to make choices regarding antithrombotic therapy , and 6-month adherence to these decisions . Their knowledge , expectations , decisional conflict ( the amount of uncertainty about the course of action to take ) , and satisfaction with the decision-making process were also measured . RESULTS More patients in the AB group made a choice about antithrombotic therapy than in the control group ( 99 % vs 94 % ; P = .02 ) . Patients in the AB group were more knowledgeable and had more realistic expectations about the risk of stroke and hemorrhage ( in the AB group , 53%-80 % correctly estimated different risks ; in the control group , 16%-28 % gave correct estimates ) . Decisional conflict and satisfaction were similar for the 2 groups . After 6 months , a similar percentage of patients were still taking their initial choice of antithrombotic therapy ( 95 % vs 93 % ; P = .44 ) . CONCLUSIONS For patients with atrial fibrillation who had participated in a major clinical trial , the use of an AB decision aid improved their underst and ing of the benefits and risks associated with different treatment options and helped them make definitive choices about which therapy to take . Further studies are necessary to evaluate the acceptability and impact of decision aids in other clinical setting In early 1983 , all 1,280 faculty and resident physicians at one hospital who were eligible to be vaccinated against hepatitis B  were divided r and omly into three groups : Group 1 physicians received general information about the risks and benefits of alternative vaccine decisions ; Group 2 physicians were additionally invited to provide personal information for an individualized decision analysis ( 12.6 percent responded ) ; and Group 3  physicians  , who served as controls , were not contacted . In one year 's follow-up , 20 percent of physicians were screened for hepatitis B antibody or vaccinated . More Group 2 physicians whose decision analyses recommended screening or vaccination took these actions ( 39 percent ) than any other group . Group assignment remained significantly associated with vaccine decisions after analyzing results by the " intention to treat " principle , and after adjusting for training status , exposure to blood and blood products , and pre- study intentions about the vaccine . Despite the low overall vaccine acceptance rate , it is concluded that individualized decision analysis can influence the clinical decisions taken by knowledgeable and interested patients BACKGROUND Given the greater uncertainty surrounding probability estimates associated with qualitative ( use of words or phrases ) descriptions , the use of quantitative ( numerical ) information to communicate the risks and benefits of therapies is recommended but the impact of its use in decision aids is unexplored . OBJECTIVE Using stroke prevention in atrial fibrillation as an example , to compare the impact of quantitative vs. qualitative descriptions of probability risk estimates in decision aids on the clinical decision-making process . DESIGN R and omized trial with a 2 x 2 factorial design . SUBJECTS A total of 198 volunteers aged 60 - 80 years . SETTING Outpatient clinics of a university-affiliated , tertiary-care teaching hospital . METHODS Participants were asked to imagine that they had atrial fibrillation , and using a decision aid , were then r and omized to two ways of receiving pertinent risk information regarding the probability of stroke and major bleeding when taking warfarin , aspirin or no therapy : ( 1 ) quantitatively , in which the 2-year probabilities of stroke and major haemorrhage were presented both numerically and graphically with 100 faces ( e.g. 8 of 100 ) , and ( 2 ) qualitatively in which these probabilities were presented with the use of verbal phrases ( e.g. very low , moderate ) . OUTCOME MEASURES Primary : decisional conflict . Secondary : participants ' choices , knowledge and expectations of outcomes using qualitative and quantitative scales . RESULTS Participants review ing quantitative risk information scored better on the informed subscale of the decisional conflict scale ( P < 0.05 ) and , as expected , were better able to estimate numerically their chance of stroke and bleeding when taking warfarin , aspirin or no medication . For the low risk arm , there were no significant differences in treatment choices for the qualitative and quantitative groups . For the moderate risk arm , treatment choices between the two groups were significantly different ( P = 0.01 ) , with those in the quantitative group more likely to make an actual choice and to choose therapies at the extremes of effectiveness ( warfarin and no treatment ) . There were no significant differences between the quantitative and qualitative groups in their ability to rank-order their stroke risk when taking  warfarin , aspirin and no treatment , overall knowledge about atrial fibrillation and its treatment , and other dimensions of decisional conflict ( all P-values > 0.05 ) . CONCLUSIONS For participants without the disease in question , this study found that providing sufficient quantitative risk information makes them feel more informed , which sometimes affects their treatment choices . Further studies are necessary to confirm these findings for patients making actual clinical decisions The management of carotid artery stenosis is an art evolving into a science , increasingly informed by clinical trials of medical management versus carotid endarterectomy ( CEA ) . Ideas about optimal management depend on the confluence of patient-specific variables , surgical expertise , and the state of medical knowledge . In this complex and progressing setting , an up-to- date decision support system could help physicians apply the latest evidence to patient care . Carotid ultrasonography ( US ) studies provide an excellent opportunity to aid in the therapy of carotid stenosis . We developed a Carotid US Report Enhancement ( CURE ) to augment carotid US reports with treatment-specific prognostic information and patient-specific portions of the American Heart Association 's 1998 guideline for the management of carotid artery stenosis . In the process of design ing and implementing the CURE software , we encountered and eventually solved a variety of problems . The first problem was that US test was not always precise enough to distinguish between a moderate and mild carotid stenosis . Likewise , the st and ard US reports did not eluci date several technical problems that decreased the reliability of the US result . Third , although 17 of 18 physicians agreed to receive the CURE reports , they requested non-incriminating wording . Fourth , vascular surgeons supervising the US laboratories were reluctant to support the CURE report if they thought it would be construed as prompting self-referral . Finally , information about some comorbid conditions ( e.g. a history of atrial fibrillation ) could not be obtained reliably from the patients . The result of responding to these problems is a decision support program that is increasingly robust , able to detect many of its own limitations , and capable of integrating data from multiple sources . A r and omized controlled trial now in progress will evaluate the clinical impact of the CURE program The Canadian Atrial Fibrillation Anticoagulation Study was a r and omized double-blind placebo-controlled trial to assess the potential of warfarin to reduce systemic thromboembolism and its inherent risk of hemorrhage . As 
    Output:
    
For patients with atrial fibrillation , treatment recommendations from clinical practice guidelines often differ from patient preferences , with substantial heterogeneity in their individual preferences .