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 The purpose of this study was to test the value of gait speed , a clinical marker for frailty , to improve the prediction of mortality and major morbidity in elderly patients undergoing cardiac surgery . BACKGROUND It is increasingly difficult to predict the elderly patient 's risk posed by cardiac surgery because existing risk assessment tools are incomplete . METHODS A multicenter prospect i ve cohort of elderly patients undergoing cardiac surgery was assembled at 4 tertiary care hospitals between 2008 and 2009 . Patients were eligible if they were 70 years of age or older and were scheduled for coronary artery bypass and /or valve replacement or repair . The primary predictor was slow gait speed , defined as a time taken to walk 5 m of ≥ 6 s. The primary end point was a composite of in-hospital post-operative mortality or major morbidity . RESULTS The cohort consisted of 131 patients with a mean age of 75.8 ± 4.4 years ; 34 % were female patients . Sixty patients ( 46 % ) were classified as slow walkers before cardiac surgery . Slow walkers were more likely to be female ( 43 % vs. 25 % , p = 0.03 ) and diabetic ( 50 % vs. 28 % , p = 0.01 ) . Thirty patients ( 23 % ) experienced the primary composite end point of mortality or major morbidity after cardiac surgery . Slow gait speed was an independent predictor of the composite end point after adjusting for the Society of Thoracic Surgeons risk score ( odds ratio : 3.05 ; 95 % confidence interval : 1.23 to 7.54 ) . CONCLUSIONS Gait speed is a simple and effective test that may identify a subset of vulnerable elderly patients at incrementally higher risk of mortality and major morbidity after cardiac surgery Background When people with stroke recover gait speed , they report improved function and reduced disability . However , the minimal amount of change in gait speed that is clinical ly meaningful and associated with an important difference in function for people poststroke has not been determined . Objective The purpose of this study was to determine the minimal clinical ly important difference ( MCID ) for comfortable gait speed ( CGS ) associated with an improvement in the modified Rankin Scale ( mRS ) score for people between 20 to 60 days poststroke . Design This was a prospect i ve , longitudinal , cohort study . Methods The participants in this study were 283 people with first-time stroke prospect ively enrolled in the ongoing Locomotor Experience Applied Post Stroke ( LEAPS ) multi-site r and omized clinical trial . Comfortable gait speed was measured and mRS scores were obtained at 20 and 60 days poststroke . Improvement of ≥1 on the mRS was used to detect meaningful change in disability level . Results Mean ( SD ) CGS was 0.18 ( 0.16 ) m/s at 20 days and 0.39 ( 0.22 ) m/s at 60 days poststroke . Among all participants , 47.3 % experienced an improvement in disability level ≥1 . The MCID was estimated as an improvement in CGS of 0.16 m/s anchored to the mRS . Limitations Because the mRS is not a gait-specific measure of disability , the estimated MCID for CGS was only 73.9 % sensitive and 57.0 % specific for detecting improvement in mRS scores . Conclusions We estimate that the MCID for gait speed among patients with subacute stroke and severe gait speed impairments is 0.16 m/s . Patients with subacute stroke who increase gait speed ≥0.16 m/s are more likely to experience a meaningful improvement in disability level than those who do not . Clinicians can use this reference value to develop goals and interpret progress in patients with subacute stroke Objective To study the relation between low walking speed and the risk of death  in older people , both overall and with regard to the main causes of death . Design Prospect i ve cohort study . Setting Dijon centre ( France ) of the Three-City study . Participants 3208 men and women aged ≥65 living in the community , recruited from 1999 to 2001 , and followed for an average of 5.1 years . Main outcome measures Mortality , overall and according to the main causes of death , by thirds of baseline walking speed ( measured at maximum speed over six metres ) , adjusted for several potential confounders ; Kaplan-Meier survival curves by thirds of baseline walking speed . Vital status during follow-up . Causes of death . Results During 16 414 person years of follow-up , 209 participants died ( 99 from cancer , 59 from cardiovascular disease , 51 from other causes ) . Participants in the lowest third of baseline walking speed had an increased risk of death ( hazard ratio 1.44 , 95 % confidence interval 1.03 to 1.99 ) compared with the upper thirds . Analyses for specific causes of death showed that participants with low walking speed had about a threefold increased risk of cardiovascular death ( 2.92 , 1.46 to 5.84 ) compared with participants who walked faster . There was no relation with cancer mortality ( 1.03 , 0.65 to 1.70 ) . In stratified analyses , cardiovascular mortality was increased across various strata defined by sex , median age , median body mass index ( BMI ) , and level of physical activity . Conclusion Slow walking speed  in older people is strongly associated with an increased risk of cardiovascular mortality Objective Performance measures provide important information , but the meaning of change in these measures is not well known . The purpose of this research is to 1 ) examine the effect of treatment assignment on the relationship between self-report and performance ; 2 ) to estimate the magnitude of meaningful change in 400- meter walk time ( 400MWT ) , 4-meter gait speed ( 4MGS ) , and Short Physical Performance Battery ( SPPB ) and 3 ) to evaluate the effect of direction of change on estimates of magnitude . Design This is a secondary analysis of data from the LIFE-P study , a single blinded r and omized clinical trial . Using change over one year , we applied distribution-based and anchor-based methods for self-reported mobility to estimate minimally important and substantial change in 400MWT , 4MGS and SPPB . Setting Four university-based clinical research sites . Participants Sedentary adults aged 70–89 whose SPPB scores were less than 10 and who were able to complete a 400MW at baseline ( n=424 ) . Interventions A structured exercise program versus health education . Measurements 400MWT , 4MGS , SPPB . Results Relationships between self-report and performance measures were consistent between treatment arms . Minimally significant change estimates were 400MWT : 20–30 seconds , 4MGS : 0.03–0.05 m/s and SPPB : 0.3–0.8 points . Substantial changes were 400MWT : 50–60 seconds , 4MGS : 0.08 m/s , SPPB : 0.4–1.5 points . Magnitudes of change for improvement and decline were not significantly different . Conclusions The magnitude of clinical ly important change in physical performance measures is reasonably consistent using several analytic techniques and appears to be achievable in clinical trials of exercise . Due to limited power , the effect of direction of change on estimates of magnitude remains uncertain OBJECTIVES To estimate meaningful improvements in gait speed observed during recovery from hip fracture and to evaluate the sensitivity and specificity of gait speed changes in detecting change in self-reported mobility . DESIGN Secondary longitudinal data analysis from two r and omized controlled trials SETTING Twelve hospitals in the Baltimore , Maryl and , area . PARTICIPANTS Two hundred seventeen women admitted with hip fracture . MEASUREMENTS  Usual gait speed and self-reported mobility ( ability to walk 1 block and climb 1 flight of stairs ) measured 2 and 12 months after fracture . RESULTS Effect size-based estimates of meaningful differences were 0.03 for small differences and 0.09 for substantial differences . Depending on the anchor ( stairs vs walking ) and method ( mean difference vs regression ) , anchor-based estimates ranged from 0.10 to 0.17 m/s for small meaningful improvements and 0.17 to 0.26 m/s for substantial meaningful improvement . Optimal gait speed cutpoints yielded low sensitivity ( 0.39 - 0.62 ) and specificity ( 0.57 - 0.76 ) for improvements in self-reported mobility . CONCLUSION Results from this sample of women recovering from hip fracture provide only limited support for the 0.10-m/s cut point for substantial meaningful change previously identified in community-dwelling older adults experiencing declines in walking abilities . Anchor-based estimates and cut points derived from receiver operating characteristic curve analysis suggest that greater improvements in gait speed may be required for substantial perceived mobility improvement in female hip fracture patients . Furthermore , gait speed change performed poorly in discriminating change in self-reported mobility . Estimates of meaningful change in gait speed may differ based on the direction of change ( improvement vs decline ) or between patient population Abstract Background : Limited data define what constitutes a clinical ly significant change on the Timed 25-Foot Walk ( T25FW ) in multiple sclerosis ( MS ) ; however , most studies suggest a value of ≥20 % . Analyses were undertaken to estimate the minimally important clinical difference ( MICD ) in walking speed as measured by the T25FW in patients with MS . Methods : Data from MS-F203 , a r and omized trial of dalfampridine extended release tablets , 10 mg twice daily ( prolonged-release/sustained-release fampridine outside the US ) in patients with MS , were used to calculate the MICD , as an absolute and percentage value , for the T25FW test . Both anchor- ( using the Clinician Global Impression [ CGI ] ) and distribution-based ( 2.77 × st and ard error of measurement or 0.50 st and ard deviation units ) approaches were used . Using the anchor-based estimations , the proportion of patients in the dalfampridine and placebo groups achieving at least a MICD in MS-F203 was determined . Results : A correlation between change in T25FW speed during and CGI at the end of double-blind period was found ( Spearman r = −0.39 , p < 0.0001 ) . Irrespective of treatment group , participants categorized ‘ minimally improved ’ by the CGI had a mean improvement in T25FW speed of 0.36 feet/second or a 17.2 % relative change from an average baseline walking speed of 2.1 feet/second ( effect size = 0.49 ) ; values representing MICDs . MICD estimates of 0.35 and 0.37 feet/second were generated using distribution-based approaches . In MS-F203 , a greater proportion of patients receiving dalfampridine achieved ≥0.36 feet/second ( 12/72 vs. 78/224 , p = 0.007 ) and a 17.2 % ( 11/72 vs. 87/224 , p = 0.0005 ) improvement in T25FW speed compared to placebo . Limitations : MICD estimates from this analysis may not apply to patients with different disease characteristics from MS-F203 . A different anchor may result in a different MICD estimation . Conclusion : Our MICD estimate for an improvement in T25FW is close to previous estimates of 20 % change . Dalfampridine may improve walking speed in a considerable proportion of patients by a clinical ly relevant amount OBJECTIVES To assess the ability of gait speed alone and a three-item lower extremity performance battery to predict 12-month rates of hospitalization , decline in health , and decline in function in primary care setting s serving older adults . DESIGN Prospect i ve cohort study . SETTING Primary care programs of a Medicare health maintenance organization ( HMO ) and Veterans Affairs ( VA ) system . PARTICIPANTS Four hundred eighty-seven persons aged 65 and older . MEASUREMENTS  Lower extremity performance Established Population for Epidemiologic Studies of the Elderly ( EPESE ) battery including  gait speed , chair st and s , and t and em balance tests ; demographics ; health care use ; health status ; functional status ; probability of repeated admission scale ( Pra ) ; and primary physician 's hospitalization risk estimate . RESULTS Veterans had poorer health and higher use than HMO members . Gait speed alone and the EPESE battery predicted hospitalization ; 41 % ( 21/51 ) of slow walkers ( gait speed < 0.6 m/s ) were hospitalized at least once , compared with 26 % ( 70/266 ) of intermediate walkers ( 0.6 - 1.0 m/s ) and 11 % ( 15/136 ) of fast walkers ( > 1.0 m/s ) ( P < .0001 ) . The relationship was stronger in the HMO than in the VA . Both performance measures remained independent predictors after accounting for Pra . The EPESE battery was superior to gait speed when both Pra and primary physician 's risk estimate were included . Both performance measures predicted decline in function and health status in both health systems . Performance measures , alone or in combination with self-report measures , were more able to predict outcomes than self-report alone . CONCLUSION Gait speed and a physical performance battery are brief , quantitative estimates of future risk for hospitalization and decline in health and function in clinical population s of older adults . Physical performance measures might serve as easily accessible " vital signs " to screen older adults in clinical setting Poststroke functional outcome and discharge disposition are influenced by age , lesion location and size , severity of neurological insult , prior functional ability , and social support . The effect of admission ambulation velocity on length of stay and discharge disposition has not been previously reported . Design . Prospect 
    Output:
    
agent
Changes in gait speed of 0.10 to 0.20 m s(-1 ) may be important across multiple patient groups
***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 The purpose of this study was to test the value of gait speed , a clinical marker for frailty , to improve the prediction of mortality and major morbidity in elderly patients undergoing cardiac surgery . BACKGROUND It is increasingly difficult to predict the elderly patient 's risk posed by cardiac surgery because existing risk assessment tools are incomplete . METHODS A multicenter prospect i ve cohort of elderly patients undergoing cardiac surgery was assembled at 4 tertiary care hospitals between 2008 and 2009 . Patients were eligible if they were 70 years of age or older and were scheduled for coronary artery bypass and /or valve replacement or repair . The primary predictor was slow gait speed , defined as a time taken to walk 5 m of ≥ 6 s. The primary end point was a composite of in-hospital post-operative mortality or major morbidity . RESULTS The cohort consisted of 131 patients with a mean age of 75.8 ± 4.4 years ; 34 % were female patients . Sixty patients ( 46 % ) were classified as slow walkers before cardiac surgery . Slow walkers were more likely to be female ( 43 % vs. 25 % , p = 0.03 ) and diabetic ( 50 % vs. 28 % , p = 0.01 ) . Thirty patients ( 23 % ) experienced the primary composite end point of mortality or major morbidity after cardiac surgery . Slow gait speed was an independent predictor of the composite end point after adjusting for the Society of Thoracic Surgeons risk score ( odds ratio : 3.05 ; 95 % confidence interval : 1.23 to 7.54 ) . CONCLUSIONS Gait speed is a simple and effective test that may identify a subset of vulnerable elderly patients at incrementally higher risk of mortality and major morbidity after cardiac surgery Background When people with stroke recover gait speed , they report improved function and reduced disability . However , the minimal amount of change in gait speed that is clinical ly meaningful and associated with an important difference in function for people poststroke has not been determined . Objective The purpose of this study was to determine the minimal clinical ly important difference ( MCID ) for comfortable gait speed ( CGS ) associated with an improvement in the modified Rankin Scale ( mRS ) score for people between 20 to 60 days poststroke . Design This was a prospect i ve , longitudinal , cohort study . Methods The participants in this study were 283 people with first-time stroke prospect ively enrolled in the ongoing Locomotor Experience Applied Post Stroke ( LEAPS ) multi-site r and omized clinical trial . Comfortable gait speed was measured and mRS scores were obtained at 20 and 60 days poststroke . Improvement of ≥1 on the mRS was used to detect meaningful change in disability level . Results Mean ( SD ) CGS was 0.18 ( 0.16 ) m/s at 20 days and 0.39 ( 0.22 ) m/s at 60 days poststroke . Among all participants , 47.3 % experienced an improvement in disability level ≥1 . The MCID was estimated as an improvement in CGS of 0.16 m/s anchored to the mRS . Limitations Because the mRS is not a gait-specific measure of disability , the estimated MCID for CGS was only 73.9 % sensitive and 57.0 % specific for detecting improvement in mRS scores . Conclusions We estimate that the MCID for gait speed among patients with subacute stroke and severe gait speed impairments is 0.16 m/s . Patients with subacute stroke who increase gait speed ≥0.16 m/s are more likely to experience a meaningful improvement in disability level than those who do not . Clinicians can use this reference value to develop goals and interpret progress in patients with subacute stroke Objective To study the relation between low walking speed and the risk of death  in older people , both overall and with regard to the main causes of death . Design Prospect i ve cohort study . Setting Dijon centre ( France ) of the Three-City study . Participants 3208 men and women aged ≥65 living in the community , recruited from 1999 to 2001 , and followed for an average of 5.1 years . Main outcome measures Mortality , overall and according to the main causes of death , by thirds of baseline walking speed ( measured at maximum speed over six metres ) , adjusted for several potential confounders ; Kaplan-Meier survival curves by thirds of baseline walking speed . Vital status during follow-up . Causes of death . Results During 16 414 person years of follow-up , 209 participants died ( 99 from cancer , 59 from cardiovascular disease , 51 from other causes ) . Participants in the lowest third of baseline walking speed had an increased risk of death ( hazard ratio 1.44 , 95 % confidence interval 1.03 to 1.99 ) compared with the upper thirds . Analyses for specific causes of death showed that participants with low walking speed had about a threefold increased risk of cardiovascular death ( 2.92 , 1.46 to 5.84 ) compared with participants who walked faster . There was no relation with cancer mortality ( 1.03 , 0.65 to 1.70 ) . In stratified analyses , cardiovascular mortality was increased across various strata defined by sex , median age , median body mass index ( BMI ) , and level of physical activity . Conclusion Slow walking speed  in older people is strongly associated with an increased risk of cardiovascular mortality Objective Performance measures provide important information , but the meaning of change in these measures is not well known . The purpose of this research is to 1 ) examine the effect of treatment assignment on the relationship between self-report and performance ; 2 ) to estimate the magnitude of meaningful change in 400- meter walk time ( 400MWT ) , 4-meter gait speed ( 4MGS ) , and Short Physical Performance Battery ( SPPB ) and 3 ) to evaluate the effect of direction of change on estimates of magnitude . Design This is a secondary analysis of data from the LIFE-P study , a single blinded r and omized clinical trial . Using change over one year , we applied distribution-based and anchor-based methods for self-reported mobility to estimate minimally important and substantial change in 400MWT , 4MGS and SPPB . Setting Four university-based clinical research sites . Participants Sedentary adults aged 70–89 whose SPPB scores were less than 10 and who were able to complete a 400MW at baseline ( n=424 ) . Interventions A structured exercise program versus health education . Measurements 400MWT , 4MGS , SPPB . Results Relationships between self-report and performance measures were consistent between treatment arms . Minimally significant change estimates were 400MWT : 20–30 seconds , 4MGS : 0.03–0.05 m/s and SPPB : 0.3–0.8 points . Substantial changes were 400MWT : 50–60 seconds , 4MGS : 0.08 m/s , SPPB : 0.4–1.5 points . Magnitudes of change for improvement and decline were not significantly different . Conclusions The magnitude of clinical ly important change in physical performance measures is reasonably consistent using several analytic techniques and appears to be achievable in clinical trials of exercise . Due to limited power , the effect of direction of change on estimates of magnitude remains uncertain OBJECTIVES To estimate meaningful improvements in gait speed observed during recovery from hip fracture and to evaluate the sensitivity and specificity of gait speed changes in detecting change in self-reported mobility . DESIGN Secondary longitudinal data analysis from two r and omized controlled trials SETTING Twelve hospitals in the Baltimore , Maryl and , area . PARTICIPANTS Two hundred seventeen women admitted with hip fracture . MEASUREMENTS  Usual gait speed and self-reported mobility ( ability to walk 1 block and climb 1 flight of stairs ) measured 2 and 12 months after fracture . RESULTS Effect size-based estimates of meaningful differences were 0.03 for small differences and 0.09 for substantial differences . Depending on the anchor ( stairs vs walking ) and method ( mean difference vs regression ) , anchor-based estimates ranged from 0.10 to 0.17 m/s for small meaningful improvements and 0.17 to 0.26 m/s for substantial meaningful improvement . Optimal gait speed cutpoints yielded low sensitivity ( 0.39 - 0.62 ) and specificity ( 0.57 - 0.76 ) for improvements in self-reported mobility . CONCLUSION Results from this sample of women recovering from hip fracture provide only limited support for the 0.10-m/s cut point for substantial meaningful change previously identified in community-dwelling older adults experiencing declines in walking abilities . Anchor-based estimates and cut points derived from receiver operating characteristic curve analysis suggest that greater improvements in gait speed may be required for substantial perceived mobility improvement in female hip fracture patients . Furthermore , gait speed change performed poorly in discriminating change in self-reported mobility . Estimates of meaningful change in gait speed may differ based on the direction of change ( improvement vs decline ) or between patient population Abstract Background : Limited data define what constitutes a clinical ly significant change on the Timed 25-Foot Walk ( T25FW ) in multiple sclerosis ( MS ) ; however , most studies suggest a value of ≥20 % . Analyses were undertaken to estimate the minimally important clinical difference ( MICD ) in walking speed as measured by the T25FW in patients with MS . Methods : Data from MS-F203 , a r and omized trial of dalfampridine extended release tablets , 10 mg twice daily ( prolonged-release/sustained-release fampridine outside the US ) in patients with MS , were used to calculate the MICD , as an absolute and percentage value , for the T25FW test . Both anchor- ( using the Clinician Global Impression [ CGI ] ) and distribution-based ( 2.77 × st and ard error of measurement or 0.50 st and ard deviation units ) approaches were used . Using the anchor-based estimations , the proportion of patients in the dalfampridine and placebo groups achieving at least a MICD in MS-F203 was determined . Results : A correlation between change in T25FW speed during and CGI at the end of double-blind period was found ( Spearman r = −0.39 , p < 0.0001 ) . Irrespective of treatment group , participants categorized ‘ minimally improved ’ by the CGI had a mean improvement in T25FW speed of 0.36 feet/second or a 17.2 % relative change from an average baseline walking speed of 2.1 feet/second ( effect size = 0.49 ) ; values representing MICDs . MICD estimates of 0.35 and 0.37 feet/second were generated using distribution-based approaches . In MS-F203 , a greater proportion of patients receiving dalfampridine achieved ≥0.36 feet/second ( 12/72 vs. 78/224 , p = 0.007 ) and a 17.2 % ( 11/72 vs. 87/224 , p = 0.0005 ) improvement in T25FW speed compared to placebo . Limitations : MICD estimates from this analysis may not apply to patients with different disease characteristics from MS-F203 . A different anchor may result in a different MICD estimation . Conclusion : Our MICD estimate for an improvement in T25FW is close to previous estimates of 20 % change . Dalfampridine may improve walking speed in a considerable proportion of patients by a clinical ly relevant amount OBJECTIVES To assess the ability of gait speed alone and a three-item lower extremity performance battery to predict 12-month rates of hospitalization , decline in health , and decline in function in primary care setting s serving older adults . DESIGN Prospect i ve cohort study . SETTING Primary care programs of a Medicare health maintenance organization ( HMO ) and Veterans Affairs ( VA ) system . PARTICIPANTS Four hundred eighty-seven persons aged 65 and older . MEASUREMENTS  Lower extremity performance Established Population for Epidemiologic Studies of the Elderly ( EPESE ) battery including  gait speed , chair st and s , and t and em balance tests ; demographics ; health care use ; health status ; functional status ; probability of repeated admission scale ( Pra ) ; and primary physician 's hospitalization risk estimate . RESULTS Veterans had poorer health and higher use than HMO members . Gait speed alone and the EPESE battery predicted hospitalization ; 41 % ( 21/51 ) of slow walkers ( gait speed < 0.6 m/s ) were hospitalized at least once , compared with 26 % ( 70/266 ) of intermediate walkers ( 0.6 - 1.0 m/s ) and 11 % ( 15/136 ) of fast walkers ( > 1.0 m/s ) ( P < .0001 ) . The relationship was stronger in the HMO than in the VA . Both performance measures remained independent predictors after accounting for Pra . The EPESE battery was superior to gait speed when both Pra and primary physician 's risk estimate were included . Both performance measures predicted decline in function and health status in both health systems . Performance measures , alone or in combination with self-report measures , were more able to predict outcomes than self-report alone . CONCLUSION Gait speed and a physical performance battery are brief , quantitative estimates of future risk for hospitalization and decline in health and function in clinical population s of older adults . Physical performance measures might serve as easily accessible " vital signs " to screen older adults in clinical setting Poststroke functional outcome and discharge disposition are influenced by age , lesion location and size , severity of neurological insult , prior functional ability , and social support . The effect of admission ambulation velocity on length of stay and discharge disposition has not been previously reported . Design . Prospect 
    Output:
    