human
***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: Objectives To assess whether screening improves the detection of atrial fibrillation  ( cluster r and omisation ) and to compare systematic and opportunistic screening . Design Multicentred cluster r and omised controlled trial , with subsidiary trial embedded within the intervention arm . Setting 50 primary care centres in Engl and , with further individual r and omisation of patients in the intervention practice s. Participants 14 802 patients aged 65 or over in 25 intervention and 25 control practice s. Interventions Patients in intervention practice s were r and omly allocated to systematic screening ( invitation for electrocardiography ) or opportunistic screening ( pulse taking and invitation for electrocardiography if the pulse was irregular ) . Screening took place over 12 months in each practice from October 2001 to February 2003 . No active screening took place in control practice s. Main outcome measure Newly identified atrial fibrillation . Results The detection rate of new cases of atrial fibrillation was 1.63 % a year in the intervention practice s and 1.04 % in control practice s ( difference 0.59 % , 95 % confidence interval 0.20 % to 0.98 % ) . Systematic and opportunistic screening detected similar numbers of new cases ( 1.62 % v 1.64 % , difference 0.02 % , −0.5 % to 0.5 % ) . Conclusion Active screening for atrial fibrillation detects additional cases over current practice . The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography . Trial registration Current Controlled Trials IS RCT N19633732 Background Atrial fibrillation ( AF ) has been recognised as an important independent risk factor for thromboembolic disease , particularly stroke for which it provides a five-fold increase in risk . This study aim ed to determine the baseline prevalence and the incidence of AF based on a variety of screening strategies and in doing so to evaluate the incremental cost-effectiveness of different screening strategies , including targeted or whole population screening , compared with routine clinical practice , for detection of AF in people aged 65 and over . The value of clinical assessment and echocardiography as additional methods of risk stratification for thromboembolic disease in patients with AF were also evaluated . Methods The study design was a multi-centre r and omised controlled trial with a study population of patients aged 65 and over from 50 General Practice s in the West Midl and s. These purpose fully selected general practice s were r and omly allocated to 25 intervention practice s and 25 control practice s. GPs and practice nurses within the intervention practice s received education on the importance of AF detection and ECG interpretation . Patients in the intervention practice s were r and omly allocated to systematic ( n = 5000 ) or opportunistic screening ( n = 5000 ) . Prospect i ve identification of pre-existing risk factors for AF within the screened population enabled comparison between high risk targeted screening and total population screening . AF detection rates in systematic ally screened and opportunistically screened population s in the intervention practice s were compared to AF detection rate in 5,000 patients in the control practice BACKGROUND Heart failure and stroke are major causes of morbidity and mortality in older people .  Angiotensin converting enzyme inhibitors improve symptoms and survival in left ventricular systolic dysfunction . Anticoagulants are effective in stroke prevention in atrial fibrillation with aspirin being a less effective alternative . OBJECTIVES To determine the prevalence of left ventricular systolic dysfunction , health services utilisation and prescribing of diuretics and angiotensin converting enzyme inhibitors in left ventricular systolic dysfunction , and the prevalence of atrial fibrillation and anti-platelet/thrombotic therapy in atrial fibrillation in older people in the community . METHODS 500 subjects were drawn by two-stage r and om sampling from 5,002 subjects aged 70 years and over living at home . Subjects were screened for atrial fibrillation and left ventricular systolic dysfunction using electrocardiography and echocardiography . RESULTS The population prevalence amongst older people of left ventricular systolic dysfunction was 9.8 % and of atrial fibrillation 7.8 % . More than two-thirds of those with left ventricular systolic dysfunction were not on angiotensin converting enzyme inhibitors . Of those in atrial fibrillation , 35 % were taking aspirin , 24 % were taking warfarin and 41 % were on neither aspirin nor warfarin . Nearly 90 % of older people in the community have had contact with their general practitioner over the past year , and over half of those with left ventricular systolic dysfunction have had contact with hospital-based services over the past 2 years . CONCLUSIONS Left ventricular systolic dysfunction is under-treated in older people in the community . Despite the high level of contact with hospital and community-based services , the majority of those with systolic left ventricular dysfunction are not on angiotensin converting enzyme inhibitors and a significant proportion of those in atrial fibrillation are not on any treatment for stroke prevention Objective To assess the accuracy of general practitioners , practice nurses , and interpretative software in the use of different types of electrocardiogram to diagnose atrial fibrillation . Design Prospect i ve comparison with reference st and ard of assessment of electrocardiograms by two independent specialists . Setting 49 general practice s in central Engl and . Participants 2595 patients aged 65 or over screened for atrial fibrillation as part of the screening for atrial fibrillation in the elderly ( SAFE ) study ; 49 general practitioners and 49 practice nurses . Interventions All electrocardiograms were read with the Biolog interpretative software , and a r and om sample of 12 lead , limb lead , and single lead thoracic placement electrocardiograms were assessed by general practitioners and practice nurses independently of each other and of the Biolog assessment . Main outcome measures Sensitivity , specificity , and positive and negative predictive values . Results General practitioners detected 79 out of 99 cases of atrial fibrillation on a 12 lead electrocardiogram ( sensitivity 80 % , 95 % confidence interval 71 % to 87 % ) and misinterpreted 114 out of 1355 cases of sinus rhythm as atrial fibrillation ( specificity 92 % , 90 % to 93 % ) . Practice nurses detected a similar proportion of cases of atrial fibrillation ( sensitivity 77 % , 67 % to 85 % ) , but had a lower specificity ( 85 % , 83 % to 87 % ) . The interpretative software was significantly more accurate , with a specificity of 99 % , but missed 36 of 215 cases of atrial fibrillation ( sensitivity 83 % ) . Combining general practitioners ' interpretation with the interpretative software led to a sensitivity of 92 % and a specificity of 91 % . Use of limb lead or single lead thoracic placement electrocardiograms result ed in some loss of specificity . Conclusions Many primary care professionals can not accurately detect atrial fibrillation on an electrocardiogram , and interpretative software is not sufficiently accurate to circumvent this problem , even when combined with interpretation by a general practitioner . Diagnosis of atrial fibrillation in the community needs to factor in the reading of electrocardiograms by appropriately trained people AIMS Atrial fibrillation ( AF ) is a major cause of morbidity , mortality , and health re source consumption . However , as many patients with chronic AF are asymptomatic , rapid , accurate opportunistic screening is needed in primary care to detect AF . Conventional electrocardiogram ( ECG ) technology is too clumsy and time consuming for mass opportunistic screening , thus technology that allows easy , rapid , yet accurate AF screening is required . To address this requirement a prototype h and -held electrode assembly was developed . We hypothesized that a 6-lead frontal-plane ECG acquired from this apparatus in a seated , clothed patient would be as accurate at detecting AF as conventional 12-lead ECG in the undressed , supine patient ( the ' gold st and ard ' ) . METHODS AND RESULTS Electrocardiograms were obtained from 78 patients with AF and 79 with sinus rhythm ( SR ) . All had a  conventional 12-lead ECG  , a 6-lead ECG from conventionally positioned limb electrodes , a supine 6-lead recording using the prototype recorder placed on the lower thorax/upper abdomen , and a 6-lead prototype recording in the seated patient , the latter with loosened clothing only . Electrocardiograms were r and omly and blindly assessed by two cardiologists for ( i ) diagnosis of AF vs. SR and ( ii ) tracing quality ( subjectively assessed as good , adequate , or bad ) . Compared with conventional 12-lead ECG recordings , all ' new ' recording methods performed satisfactorily with sensitivities ≥90 % ( 90 - 99 % ) , specificities ≥94 % ( 94 - 100 % ) , positive predictive values ≥94 % ( 94 - 100 % ) , negative predictive values ≥90 % ( 90 - 99 % ) , and accuracies ≥93 % ( 93 - 99 % ) . Tracing quality was higher in conventional 12-lead recordings ( 71 and 80 % were assessed as good by the two observers ) compared with conventional 6-lead ( 57 and 59 % ) , supine prototype ( 41 and 31 % ) , and sitting prototype ( 39 and 19 % ) . CONCLUSIONS Despite inferior electrocardiographic quality a 6-lead frontal plane ECG acquired by a simple prototype h and -held electrode assembly allowed reliable differentiation of AF from SR compared with st and ard 12-lead ECG Objectives : To assess the demographic and psychological mediators of gender differences in uptake of flexible sigmoidoscopy ( FS ) screening for colorectal cancer . Setting : A sub sample ( n=5462 ) from a large community trial of FS in the UK . Methods : Men and women r and omized to screening as part of the UK Flexible Sigmoidoscopy Trial were sent a postal question naire assessing  demographic characteristics and  attitudes  to screening six months before their screening appointment . Attendance at screening  was recorded by the screening centres . Results : More men than women  attended screening  ( 73 % versus 67 % ) . The higher male attendance was partially explained by their lower levels of socioeconomic deprivation , higher levels of marital status and lower perceived barriers to screening . Conclusions : Contrary to expectations , men weremore likely than women to attend FS screening .  This was partially explained by socioeconomic and attitudinal differences to screening , but additional research is needed to underst and the key aspects of FS screening that will maximize screening uptake in men and women Background : Atrial fibrillation is a common arrhythmia associated with excess morbidity and mortality . We studied temporal changes in hospital admission rates for atrial fibrillation using data from a prospect i ve population -based cohort study spanning 2 decades ( the Copenhagen City Heart Study ) . Methods : The study included baseline data collected in 1981 through 1983 on 10,955 persons age 40 to 79 years and baseline data collected in 1991 through 1994 on 7212 persons age 40 to 79 years . We used hospital diagnosis data from the Danish National Hospital Discharge Register to determine the rate of first hospital admission for atrial fibrillation during 7 years following each of the 2 baseline data collecting periods . Changes in admission rates were analyzed using Cox proportional hazard models . Results : During the 2 7-year periods , 379 subjects were admitted with a hospital diagnosis of atrial fibrillation . The rate of hospital admissions for atrial fibrillation increased among both men and women from the first to the second period ( relative risk = 1.6 ; 95 % confidence interval = 1.3–1.9 [ adjusted for age , sex , prior myocardial infa rct ion , arterial hypertension , diabetes mellitus , electrocardiographic left ventricular hypertrophy , decreased lung function , smoking , height , and weight ] ) . Conclusion : During the latest 10 to 20 years , there has been a 60 % increase in hospital admissions for atrial fibrillation independent of changes in known risk factors . This increase could result from changes in admission threshold or coding practice s , or it could reflect a genuine increase in the population incidence of atrial fibrillation BACKGROUND AND PURPOSE Stroke occurring with atrial fibrillation ( AF )  is more likely to be fatal or more severe than non-AF stroke based on clinical series , but data from prospect i ve epidemiological studies are sparse and inconsistent . METHODS Over 40-year follow-up of the original 5070 Framingham cohort , 501 initial ischemic strokes , including 103 with AF , were analyzed . Stroke severity was rated as none , mild , moderate , severe , or fatal . Since 1981 , functional status indicated by the Barthel index has been evaluated acutely and at 3 , 6 , and 12 months . Severity and functional status of AF strokes were compared with non-AF strokes using chi 2 test and Student 's t test . Thirty-day mortality was assessed by logistic regression analyses . RESULTS AF was associated with increased stroke severity ( P = .048 ) . Thirty-day mortality was greater in AF strokes than in non-AF strokes ( 
    Output:
    
agent
Systematic and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice .
While both approaches have a comparable effect on the overall AF diagnosis rate , the cost of systematic screening is significantly more than that of opportunistic screening from the perspective of the health service provider .
***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: Objectives To assess whether screening improves the detection of atrial fibrillation  ( cluster r and omisation ) and to compare systematic and opportunistic screening . Design Multicentred cluster r and omised controlled trial , with subsidiary trial embedded within the intervention arm . Setting 50 primary care centres in Engl and , with further individual r and omisation of patients in the intervention practice s. Participants 14 802 patients aged 65 or over in 25 intervention and 25 control practice s. Interventions Patients in intervention practice s were r and omly allocated to systematic screening ( invitation for electrocardiography ) or opportunistic screening ( pulse taking and invitation for electrocardiography if the pulse was irregular ) . Screening took place over 12 months in each practice from October 2001 to February 2003 . No active screening took place in control practice s. Main outcome measure Newly identified atrial fibrillation . Results The detection rate of new cases of atrial fibrillation was 1.63 % a year in the intervention practice s and 1.04 % in control practice s ( difference 0.59 % , 95 % confidence interval 0.20 % to 0.98 % ) . Systematic and opportunistic screening detected similar numbers of new cases ( 1.62 % v 1.64 % , difference 0.02 % , −0.5 % to 0.5 % ) . Conclusion Active screening for atrial fibrillation detects additional cases over current practice . The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography . Trial registration Current Controlled Trials IS RCT N19633732 Background Atrial fibrillation ( AF ) has been recognised as an important independent risk factor for thromboembolic disease , particularly stroke for which it provides a five-fold increase in risk . This study aim ed to determine the baseline prevalence and the incidence of AF based on a variety of screening strategies and in doing so to evaluate the incremental cost-effectiveness of different screening strategies , including targeted or whole population screening , compared with routine clinical practice , for detection of AF in people aged 65 and over . The value of clinical assessment and echocardiography as additional methods of risk stratification for thromboembolic disease in patients with AF were also evaluated . Methods The study design was a multi-centre r and omised controlled trial with a study population of patients aged 65 and over from 50 General Practice s in the West Midl and s. These purpose fully selected general practice s were r and omly allocated to 25 intervention practice s and 25 control practice s. GPs and practice nurses within the intervention practice s received education on the importance of AF detection and ECG interpretation . Patients in the intervention practice s were r and omly allocated to systematic ( n = 5000 ) or opportunistic screening ( n = 5000 ) . Prospect i ve identification of pre-existing risk factors for AF within the screened population enabled comparison between high risk targeted screening and total population screening . AF detection rates in systematic ally screened and opportunistically screened population s in the intervention practice s were compared to AF detection rate in 5,000 patients in the control practice BACKGROUND Heart failure and stroke are major causes of morbidity and mortality in older people .  Angiotensin converting enzyme inhibitors improve symptoms and survival in left ventricular systolic dysfunction . Anticoagulants are effective in stroke prevention in atrial fibrillation with aspirin being a less effective alternative . OBJECTIVES To determine the prevalence of left ventricular systolic dysfunction , health services utilisation and prescribing of diuretics and angiotensin converting enzyme inhibitors in left ventricular systolic dysfunction , and the prevalence of atrial fibrillation and anti-platelet/thrombotic therapy in atrial fibrillation in older people in the community . METHODS 500 subjects were drawn by two-stage r and om sampling from 5,002 subjects aged 70 years and over living at home . Subjects were screened for atrial fibrillation and left ventricular systolic dysfunction using electrocardiography and echocardiography . RESULTS The population prevalence amongst older people of left ventricular systolic dysfunction was 9.8 % and of atrial fibrillation 7.8 % . More than two-thirds of those with left ventricular systolic dysfunction were not on angiotensin converting enzyme inhibitors . Of those in atrial fibrillation , 35 % were taking aspirin , 24 % were taking warfarin and 41 % were on neither aspirin nor warfarin . Nearly 90 % of older people in the community have had contact with their general practitioner over the past year , and over half of those with left ventricular systolic dysfunction have had contact with hospital-based services over the past 2 years . CONCLUSIONS Left ventricular systolic dysfunction is under-treated in older people in the community . Despite the high level of contact with hospital and community-based services , the majority of those with systolic left ventricular dysfunction are not on angiotensin converting enzyme inhibitors and a significant proportion of those in atrial fibrillation are not on any treatment for stroke prevention Objective To assess the accuracy of general practitioners , practice nurses , and interpretative software in the use of different types of electrocardiogram to diagnose atrial fibrillation . Design Prospect i ve comparison with reference st and ard of assessment of electrocardiograms by two independent specialists . Setting 49 general practice s in central Engl and . Participants 2595 patients aged 65 or over screened for atrial fibrillation as part of the screening for atrial fibrillation in the elderly ( SAFE ) study ; 49 general practitioners and 49 practice nurses . Interventions All electrocardiograms were read with the Biolog interpretative software , and a r and om sample of 12 lead , limb lead , and single lead thoracic placement electrocardiograms were assessed by general practitioners and practice nurses independently of each other and of the Biolog assessment . Main outcome measures Sensitivity , specificity , and positive and negative predictive values . Results General practitioners detected 79 out of 99 cases of atrial fibrillation on a 12 lead electrocardiogram ( sensitivity 80 % , 95 % confidence interval 71 % to 87 % ) and misinterpreted 114 out of 1355 cases of sinus rhythm as atrial fibrillation ( specificity 92 % , 90 % to 93 % ) . Practice nurses detected a similar proportion of cases of atrial fibrillation ( sensitivity 77 % , 67 % to 85 % ) , but had a lower specificity ( 85 % , 83 % to 87 % ) . The interpretative software was significantly more accurate , with a specificity of 99 % , but missed 36 of 215 cases of atrial fibrillation ( sensitivity 83 % ) . Combining general practitioners ' interpretation with the interpretative software led to a sensitivity of 92 % and a specificity of 91 % . Use of limb lead or single lead thoracic placement electrocardiograms result ed in some loss of specificity . Conclusions Many primary care professionals can not accurately detect atrial fibrillation on an electrocardiogram , and interpretative software is not sufficiently accurate to circumvent this problem , even when combined with interpretation by a general practitioner . Diagnosis of atrial fibrillation in the community needs to factor in the reading of electrocardiograms by appropriately trained people AIMS Atrial fibrillation ( AF ) is a major cause of morbidity , mortality , and health re source consumption . However , as many patients with chronic AF are asymptomatic , rapid , accurate opportunistic screening is needed in primary care to detect AF . Conventional electrocardiogram ( ECG ) technology is too clumsy and time consuming for mass opportunistic screening , thus technology that allows easy , rapid , yet accurate AF screening is required . To address this requirement a prototype h and -held electrode assembly was developed . We hypothesized that a 6-lead frontal-plane ECG acquired from this apparatus in a seated , clothed patient would be as accurate at detecting AF as conventional 12-lead ECG in the undressed , supine patient ( the ' gold st and ard ' ) . METHODS AND RESULTS Electrocardiograms were obtained from 78 patients with AF and 79 with sinus rhythm ( SR ) . All had a  conventional 12-lead ECG  , a 6-lead ECG from conventionally positioned limb electrodes , a supine 6-lead recording using the prototype recorder placed on the lower thorax/upper abdomen , and a 6-lead prototype recording in the seated patient , the latter with loosened clothing only . Electrocardiograms were r and omly and blindly assessed by two cardiologists for ( i ) diagnosis of AF vs. SR and ( ii ) tracing quality ( subjectively assessed as good , adequate , or bad ) . Compared with conventional 12-lead ECG recordings , all ' new ' recording methods performed satisfactorily with sensitivities ≥90 % ( 90 - 99 % ) , specificities ≥94 % ( 94 - 100 % ) , positive predictive values ≥94 % ( 94 - 100 % ) , negative predictive values ≥90 % ( 90 - 99 % ) , and accuracies ≥93 % ( 93 - 99 % ) . Tracing quality was higher in conventional 12-lead recordings ( 71 and 80 % were assessed as good by the two observers ) compared with conventional 6-lead ( 57 and 59 % ) , supine prototype ( 41 and 31 % ) , and sitting prototype ( 39 and 19 % ) . CONCLUSIONS Despite inferior electrocardiographic quality a 6-lead frontal plane ECG acquired by a simple prototype h and -held electrode assembly allowed reliable differentiation of AF from SR compared with st and ard 12-lead ECG Objectives : To assess the demographic and psychological mediators of gender differences in uptake of flexible sigmoidoscopy ( FS ) screening for colorectal cancer . Setting : A sub sample ( n=5462 ) from a large community trial of FS in the UK . Methods : Men and women r and omized to screening as part of the UK Flexible Sigmoidoscopy Trial were sent a postal question naire assessing  demographic characteristics and  attitudes  to screening six months before their screening appointment . Attendance at screening  was recorded by the screening centres . Results : More men than women  attended screening  ( 73 % versus 67 % ) . The higher male attendance was partially explained by their lower levels of socioeconomic deprivation , higher levels of marital status and lower perceived barriers to screening . Conclusions : Contrary to expectations , men weremore likely than women to attend FS screening .  This was partially explained by socioeconomic and attitudinal differences to screening , but additional research is needed to underst and the key aspects of FS screening that will maximize screening uptake in men and women Background : Atrial fibrillation is a common arrhythmia associated with excess morbidity and mortality . We studied temporal changes in hospital admission rates for atrial fibrillation using data from a prospect i ve population -based cohort study spanning 2 decades ( the Copenhagen City Heart Study ) . Methods : The study included baseline data collected in 1981 through 1983 on 10,955 persons age 40 to 79 years and baseline data collected in 1991 through 1994 on 7212 persons age 40 to 79 years . We used hospital diagnosis data from the Danish National Hospital Discharge Register to determine the rate of first hospital admission for atrial fibrillation during 7 years following each of the 2 baseline data collecting periods . Changes in admission rates were analyzed using Cox proportional hazard models . Results : During the 2 7-year periods , 379 subjects were admitted with a hospital diagnosis of atrial fibrillation . The rate of hospital admissions for atrial fibrillation increased among both men and women from the first to the second period ( relative risk = 1.6 ; 95 % confidence interval = 1.3–1.9 [ adjusted for age , sex , prior myocardial infa rct ion , arterial hypertension , diabetes mellitus , electrocardiographic left ventricular hypertrophy , decreased lung function , smoking , height , and weight ] ) . Conclusion : During the latest 10 to 20 years , there has been a 60 % increase in hospital admissions for atrial fibrillation independent of changes in known risk factors . This increase could result from changes in admission threshold or coding practice s , or it could reflect a genuine increase in the population incidence of atrial fibrillation BACKGROUND AND PURPOSE Stroke occurring with atrial fibrillation ( AF )  is more likely to be fatal or more severe than non-AF stroke based on clinical series , but data from prospect i ve epidemiological studies are sparse and inconsistent . METHODS Over 40-year follow-up of the original 5070 Framingham cohort , 501 initial ischemic strokes , including 103 with AF , were analyzed . Stroke severity was rated as none , mild , moderate , severe , or fatal . Since 1981 , functional status indicated by the Barthel index has been evaluated acutely and at 3 , 6 , and 12 months . Severity and functional status of AF strokes were compared with non-AF strokes using chi 2 test and Student 's t test . Thirty-day mortality was assessed by logistic regression analyses . RESULTS AF was associated with increased stroke severity ( P = .048 ) . Thirty-day mortality was greater in AF strokes than in non-AF strokes ( 
    Output:
    