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: BACKGROUND A major obstacle to screening for early mobility disability ( ie , mobility difficulty ) , a major public health concern , is the lack of a method that identifies those who are at high risk . The goal of this study was to develop easy-to-use clinical nomograms for estimation of the probability of incident mobility difficulty . METHODS We conducted a population -based prospect i ve study using data from 266 high physically and cognitively functioning older women , aged 70 to 80 years , who were free of mobility disability at the baseline evaluation of the Women 's Health and Aging Study II . The outcome measure was incident mobility disability within 18 months , defined as self-reported difficulty walking 0.8 km , climbing 10 steps , or transferring from or into a car or bus . Logistic regression and receiver operating characteristic curve analyses were used for evaluation of the optimal combination of self-reported and performance-based mobility measures . Bootstrap sampling and estimation was used for validation . RESULTS Predictive nomograms were developed based on a final model that included 3 simple-to-obtain measures of pre clinical disability : self-report of modification in mobility tasks without having difficulty with them , one-leg stance balance , and time to walk 1 m at a usual pace . Final model accuracy ( as estimated by the area under the receiver operating characteristic curve ) was 73 % ( SE = 0.04 ) . Validation analysis confirmed the high accuracy of these nomograms . CONCLUSIONS An original tool was developed for assessment of the risk of mobility difficulty in older women that can be used to assist physicians and research ers in deciding which women to target for preventive interventions OBJECTIVES To vali date self-reported pre clinical mobility limitation concept and self-report assessment method against muscle power and walking speed , and to study the predictive validity of pre clinical mobility limitation with respect to future risk of manifest mobility limitation . DESIGN Observational prospect i ve cohort study and cross-sectional analysis . SETTING Research laboratory and community . PARTICIPANTS A total of 632 community-living ( age range , 75 - 81 y ) women and men took part in the baseline assessment s and 302 persons in the semi-annual interviews on mobility limitation over 2 years . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Walking speed , muscle power , and self-reported pre clinical and manifest mobility limitation . Pre clinical mobility limitation was defined as self-reported tiredness or modification of task performance without task difficulty . At baseline , 4 subgroups were created according to self-reported pre clinical mobility limitation in any of 3 mobility tasks ( walking 2 km , walking 0.5 km , climbing up stairs ) : no limitation , pre clinical limitation , and minor and major manifest limitation . RESULTS At baseline , participants with pre clinical mobility limitation showed intermediate levels of walking speed and muscle power , compared with those with no limitation or manifest mobility limitation . Participants reporting baseline pre clinical mobility limitation had 3- to 6-fold higher age- and sex-adjusted risk of progressing to major manifest mobility limitation during the 2-year follow-up compared with participants with no limitation at baseline , whereas the risk among those with minor limitation at baseline was 14- to 18-fold higher compared with those with no limitation . CONCLUSIONS The self-report assessment tool proved to be a valid measure to capture the early signs of disability and may serve as an inexpensive tool for identifying those nondisabled persons at high risk for future disability OBJECTIVES To identify levels of knee extensor strength that are associated with high and low risk of incident  severe mobility limitation ( SML ) in initially well-functioning older adults . DESIGN Prospect i ve cohort study . SETTING University clinic center . PARTICIPANTS One thous and three hundred fifty-five men and 1,429 women ( aged 73.6+/-2.85 ) who reported no mobility limitation . MEASUREMENTS Unilateral knee extensor isokinetic strength of participants was obtained . Participants were followed over a median of 5.90 years for the onset of SML , defined as two consecutive reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps . Deciles of knee extension strength relative to body weight were evaluated to identify cutpoints most predictive of incident SML . Cutpoints were then compared with prevalence of having slow gait speed ( < 1.22 m/s ) and mortality . RESULTS Two sex-specific knee extension strength cutpoints were found . High and low risk of SML corresponded to less than 1.13 newton-meters (Nm)/kg ( 1st decile ) and more than 1.71 Nm/kg ( 6th decile ) in men and less than 1.01 Nm/kg ( 3rd decile ) and more than 1.34 Nm/kg ( 7th decile ) in women , respectively . Moderate risk was defined as being between the low- and high-risk cutpoints . Individuals with knee extension strength in the high- and moderate-risk categories were more likely to have a gait speed less than 1.22 m/s ( hazard ratio (HR)=7.00 , 95 % confidence interval (CI)=5.47 - 8.96 and HR=2.14 7.00 , 95 % CI=1.73 - 2.64 , respectively ) and had a higher risk of death ( HR=1.77 , 95 % CI=1.41 - 2.23 and HR=1.51 , 95 % CI=1.24 - 1.84 , respectively ) than individuals in the low-risk category . Adjustment for demographic factors , health behaviors , and medical conditions did not alter these associations . CONCLUSION Knee extensor strength cutpoints provide objective markers to identify initially well-functioning older adults at high and low risk of future mobility limitation Background Interventions that enhance mobility in frail older people are needed to maintain health and independence , yet definitive evidence of effective interventions is lacking . Our objective was to assess the impact of a multifactorial intervention on mobility-related disability in frail older people . Methods We conducted a r and omised , controlled trial with 241 frail community-dwelling older people in Sydney , Australia . Participants were classified as frail using the Cardiovascular Health Study definition , did not have severe cognitive impairment and were recently discharged from an aged care and rehabilitation service . The experimental group received a 12 month multifactorial , interdisciplinary intervention targeting identified frailty components . Two physiotherapists delivered a home exercise program targeting mobility , and coordinated management of psychological and medical conditions with other health professionals . The control group received usual care .  Disability in the mobility domain was measured at baseline and at 3 and 12 months using the International Classification of Functioning , Disability and Health framework . Participation ( involvement in life situations ) was assessed using the Life Space Assessment and the Goal Attainment Scale . Activity ( execution of mobility tasks ) was measured using the 4-metre walk and self-report measures . Results The mean age of participants was 83.3 years ( SD : 5.9 years ) . Of the participants recruited , 216 ( 90 % ) were followed-up at 12 months . At this time point , the intervention group had significantly better scores than the control group on the Goal Attainment Scale ( odds ratio 2.1 ; 95 % confidence interval ( CI ) 1.3 to 3.3 , P = 0.004 ) and Life Space Assessment ( 4.68 points , 95 % CI 1.4 to 9.9 , P = 0.005 ) . There was no difference between groups on the global measure of participation or satisfaction with ability to get out of the house . At the activity level , the intervention group walked 0.05 m/s faster over 4 m ( 95 % CI 0.0004 to 0.1 , P = 0.048 ) than the control group , and scored higher on the Activity Measure for Post Acute Care ( P < 0.001 ) . Conclusions The intervention reduced mobility-related disability in frail older people . The benefit was evident at both the participation and activity levels of mobility-related disability . Trial registration Australia and New Zeal and Clinical Trials Register ( ANZCTR ) : ANZCTRN12608000507381 OBJECTIVE To examine changes in functional status over time by age , gender , and ethnicity in a representative sample of older persons . DESIGN Six-year prospect i ve cohort study . SETTING Alameda County , California . PARTICIPANTS 508 persons 65 years old and older at baseline in 1984 . MAIN OUTCOME MEASURES Activities of daily living ( ADL ) dependence , mobility impairment , and functioning on an 18-item scale . RESULTS The prevalence of ADL dependence and mobility impairment at baseline increased with age , while function decreased . Particularly striking differences occurred for those 80 and older . Changes in function over the 6-year follow-up showed a similar pattern . While death rates for males were higher , females had poorer initial functioning , and surviving females declined more than surviving males . The incidence of ADL dependence and mobility impairment during follow-up was similar for males and females , although females survived longer with incident disability than did males . Blacks had poorer baseline functioning , more ADL dependence and mobility impairment , and declined more than non-Blacks during follow-up . Some of the baseline difference in function between Blacks and non-Blacks was due to higher rates of chronic illness and co-morbidity . In spite of the general downward trend in functioning over the 6 years , 13 % of the males and 20 % of the females improved . CONCLUSION Age-related changes in function for older persons are complex and result in much heterogeneity . Clarifying the reasons for such heterogeneity is an important and challenging area of research Background and aims : Prospect i ve studies on the simultaneous effects of multiple determinants on objective ly assessed mobility are few . The aim of this study was to analyse mobility performance , its stability and sensory , psychomotor and musculoskeletal determinants in an older population from age 75 to age 80 . Methods : Sixty-three men and 121 women aged 75 participated at baseline and , five years later , in the follow-up phase of this population -based prospect i ve study .  Maximal walking speed and step-mounting height were assessed at baseline and follow-up . Maximal isometric knee extension strength , st and ing balance on force platform , reaction time , visual acuity and limitations in range of motion ( ROM ) of hips and knees were assessed at baseline . Structural equation modeling was used to analyse the associations . Results : The stability of mobility performance from baseline to the five-year follow-up was high ( coefficient 0.80 in men , 0.78 in women ) . In men , knee extension strength , st and ing balance , ROM limitations and visual acuity explained 69 % of the variation in mobility performance at baseline and , indirectly , 59 % of that variation at follow-up . Among women , knee extension strength , st and ing balance , visual acuity and reaction time explained 52 % of the variation of mobility performance at baseline and , indirectly , 30 % at the five-year follow-up . Conclusions : Results indicate that the predictive effects of sensory , psychomotor and musculoskeletal functions on mobility performance extend over five years in older people . In seeking to prevent mobility limitations , vision , reaction time and lower extremity ROM need to be targeted , in addition to muscle strength and balance BACKGROUND in the primary prevention of disability among older adults it might be useful to identify individuals at high risk for functional decline before it occurs . OBJECTIVE to examine whether  tiredness in daily activities  is an independent determinant of onset of mobility disability at 1 1/2-year follow-up among non-disabled older men and women . DESIGN a prospect i ve study with 1 1/2-year follow-up . SETTING 34 communities in four counties in Denmark . SUBJECTS 1396 older non-disabled adults ( 74 - 75 and 80 years old ) living in 17 of the participating communities . METHODS question naire surveys at baseline and at 1 1/2-year follow-up . Tiredness in daily activities  was measured by questions about tiredness in six mobility activities . Onset of mobility disability was measured as onset of need for help in one to six mobility activities . RESULTS men and women who felt tired in their daily activities at baseline had a higher risk of onset of mobility disability at 1 1/2-year follow-up , when adjusted by the covariates . In addition , low social participation , poor psychological function , and physical inactivity were independent risk factors of onset of mobility disability among men , and home help , low sense of coherence and physical inactivity were independent risk factors of onset of mobility disability among women . CONCLUSION older people who complain about tiredness are at higher risk of becoming disabled than others . This highlights the need for alertness and management of this early sign of functional decline in a preventive perspective BACKGROUND numerous tests have been suggested as fall risk indicators . However , the validity of these assessment s has not been demonstrated in large representative sample s of community-dwelling older people . OBJECTIVE the objective of this study was to examine the comparative ability and clinical utility of eight mobility tests for predicting multiple falls in older community-dwelling people . METHODS design -- prospect i ve cohort study ; subjects--362 subjects aged 74 - 98 years ; measurements --the sit-to-st and test with one and five repetitions , the pick-up-weight test , the half-turn test , the alternate-step test ( AST ) , the six-metre-walk test ( SMWT )  and  stair ascent and descent tasks . Falls were monitored for 1 year with fall calendars . RESULTS in the 12-month follow-up period , 80 subjects ( 22.1 % ) suffered two or more falls . Multiple fallers 
    Output:
    
agent
Commonly measured constructs of mobility included walking , climbing stairs , and lower extremity function .
There was heterogeneity in ways of defining and measuring mobility limitation in older adults living in the community .
***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 A major obstacle to screening for early mobility disability ( ie , mobility difficulty ) , a major public health concern , is the lack of a method that identifies those who are at high risk . The goal of this study was to develop easy-to-use clinical nomograms for estimation of the probability of incident mobility difficulty . METHODS We conducted a population -based prospect i ve study using data from 266 high physically and cognitively functioning older women , aged 70 to 80 years , who were free of mobility disability at the baseline evaluation of the Women 's Health and Aging Study II . The outcome measure was incident mobility disability within 18 months , defined as self-reported difficulty walking 0.8 km , climbing 10 steps , or transferring from or into a car or bus . Logistic regression and receiver operating characteristic curve analyses were used for evaluation of the optimal combination of self-reported and performance-based mobility measures . Bootstrap sampling and estimation was used for validation . RESULTS Predictive nomograms were developed based on a final model that included 3 simple-to-obtain measures of pre clinical disability : self-report of modification in mobility tasks without having difficulty with them , one-leg stance balance , and time to walk 1 m at a usual pace . Final model accuracy ( as estimated by the area under the receiver operating characteristic curve ) was 73 % ( SE = 0.04 ) . Validation analysis confirmed the high accuracy of these nomograms . CONCLUSIONS An original tool was developed for assessment of the risk of mobility difficulty in older women that can be used to assist physicians and research ers in deciding which women to target for preventive interventions OBJECTIVES To vali date self-reported pre clinical mobility limitation concept and self-report assessment method against muscle power and walking speed , and to study the predictive validity of pre clinical mobility limitation with respect to future risk of manifest mobility limitation . DESIGN Observational prospect i ve cohort study and cross-sectional analysis . SETTING Research laboratory and community . PARTICIPANTS A total of 632 community-living ( age range , 75 - 81 y ) women and men took part in the baseline assessment s and 302 persons in the semi-annual interviews on mobility limitation over 2 years . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Walking speed , muscle power , and self-reported pre clinical and manifest mobility limitation . Pre clinical mobility limitation was defined as self-reported tiredness or modification of task performance without task difficulty . At baseline , 4 subgroups were created according to self-reported pre clinical mobility limitation in any of 3 mobility tasks ( walking 2 km , walking 0.5 km , climbing up stairs ) : no limitation , pre clinical limitation , and minor and major manifest limitation . RESULTS At baseline , participants with pre clinical mobility limitation showed intermediate levels of walking speed and muscle power , compared with those with no limitation or manifest mobility limitation . Participants reporting baseline pre clinical mobility limitation had 3- to 6-fold higher age- and sex-adjusted risk of progressing to major manifest mobility limitation during the 2-year follow-up compared with participants with no limitation at baseline , whereas the risk among those with minor limitation at baseline was 14- to 18-fold higher compared with those with no limitation . CONCLUSIONS The self-report assessment tool proved to be a valid measure to capture the early signs of disability and may serve as an inexpensive tool for identifying those nondisabled persons at high risk for future disability OBJECTIVES To identify levels of knee extensor strength that are associated with high and low risk of incident  severe mobility limitation ( SML ) in initially well-functioning older adults . DESIGN Prospect i ve cohort study . SETTING University clinic center . PARTICIPANTS One thous and three hundred fifty-five men and 1,429 women ( aged 73.6+/-2.85 ) who reported no mobility limitation . MEASUREMENTS Unilateral knee extensor isokinetic strength of participants was obtained . Participants were followed over a median of 5.90 years for the onset of SML , defined as two consecutive reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps . Deciles of knee extension strength relative to body weight were evaluated to identify cutpoints most predictive of incident SML . Cutpoints were then compared with prevalence of having slow gait speed ( < 1.22 m/s ) and mortality . RESULTS Two sex-specific knee extension strength cutpoints were found . High and low risk of SML corresponded to less than 1.13 newton-meters (Nm)/kg ( 1st decile ) and more than 1.71 Nm/kg ( 6th decile ) in men and less than 1.01 Nm/kg ( 3rd decile ) and more than 1.34 Nm/kg ( 7th decile ) in women , respectively . Moderate risk was defined as being between the low- and high-risk cutpoints . Individuals with knee extension strength in the high- and moderate-risk categories were more likely to have a gait speed less than 1.22 m/s ( hazard ratio (HR)=7.00 , 95 % confidence interval (CI)=5.47 - 8.96 and HR=2.14 7.00 , 95 % CI=1.73 - 2.64 , respectively ) and had a higher risk of death ( HR=1.77 , 95 % CI=1.41 - 2.23 and HR=1.51 , 95 % CI=1.24 - 1.84 , respectively ) than individuals in the low-risk category . Adjustment for demographic factors , health behaviors , and medical conditions did not alter these associations . CONCLUSION Knee extensor strength cutpoints provide objective markers to identify initially well-functioning older adults at high and low risk of future mobility limitation Background Interventions that enhance mobility in frail older people are needed to maintain health and independence , yet definitive evidence of effective interventions is lacking . Our objective was to assess the impact of a multifactorial intervention on mobility-related disability in frail older people . Methods We conducted a r and omised , controlled trial with 241 frail community-dwelling older people in Sydney , Australia . Participants were classified as frail using the Cardiovascular Health Study definition , did not have severe cognitive impairment and were recently discharged from an aged care and rehabilitation service . The experimental group received a 12 month multifactorial , interdisciplinary intervention targeting identified frailty components . Two physiotherapists delivered a home exercise program targeting mobility , and coordinated management of psychological and medical conditions with other health professionals . The control group received usual care .  Disability in the mobility domain was measured at baseline and at 3 and 12 months using the International Classification of Functioning , Disability and Health framework . Participation ( involvement in life situations ) was assessed using the Life Space Assessment and the Goal Attainment Scale . Activity ( execution of mobility tasks ) was measured using the 4-metre walk and self-report measures . Results The mean age of participants was 83.3 years ( SD : 5.9 years ) . Of the participants recruited , 216 ( 90 % ) were followed-up at 12 months . At this time point , the intervention group had significantly better scores than the control group on the Goal Attainment Scale ( odds ratio 2.1 ; 95 % confidence interval ( CI ) 1.3 to 3.3 , P = 0.004 ) and Life Space Assessment ( 4.68 points , 95 % CI 1.4 to 9.9 , P = 0.005 ) . There was no difference between groups on the global measure of participation or satisfaction with ability to get out of the house . At the activity level , the intervention group walked 0.05 m/s faster over 4 m ( 95 % CI 0.0004 to 0.1 , P = 0.048 ) than the control group , and scored higher on the Activity Measure for Post Acute Care ( P < 0.001 ) . Conclusions The intervention reduced mobility-related disability in frail older people . The benefit was evident at both the participation and activity levels of mobility-related disability . Trial registration Australia and New Zeal and Clinical Trials Register ( ANZCTR ) : ANZCTRN12608000507381 OBJECTIVE To examine changes in functional status over time by age , gender , and ethnicity in a representative sample of older persons . DESIGN Six-year prospect i ve cohort study . SETTING Alameda County , California . PARTICIPANTS 508 persons 65 years old and older at baseline in 1984 . MAIN OUTCOME MEASURES Activities of daily living ( ADL ) dependence , mobility impairment , and functioning on an 18-item scale . RESULTS The prevalence of ADL dependence and mobility impairment at baseline increased with age , while function decreased . Particularly striking differences occurred for those 80 and older . Changes in function over the 6-year follow-up showed a similar pattern . While death rates for males were higher , females had poorer initial functioning , and surviving females declined more than surviving males . The incidence of ADL dependence and mobility impairment during follow-up was similar for males and females , although females survived longer with incident disability than did males . Blacks had poorer baseline functioning , more ADL dependence and mobility impairment , and declined more than non-Blacks during follow-up . Some of the baseline difference in function between Blacks and non-Blacks was due to higher rates of chronic illness and co-morbidity . In spite of the general downward trend in functioning over the 6 years , 13 % of the males and 20 % of the females improved . CONCLUSION Age-related changes in function for older persons are complex and result in much heterogeneity . Clarifying the reasons for such heterogeneity is an important and challenging area of research Background and aims : Prospect i ve studies on the simultaneous effects of multiple determinants on objective ly assessed mobility are few . The aim of this study was to analyse mobility performance , its stability and sensory , psychomotor and musculoskeletal determinants in an older population from age 75 to age 80 . Methods : Sixty-three men and 121 women aged 75 participated at baseline and , five years later , in the follow-up phase of this population -based prospect i ve study .  Maximal walking speed and step-mounting height were assessed at baseline and follow-up . Maximal isometric knee extension strength , st and ing balance on force platform , reaction time , visual acuity and limitations in range of motion ( ROM ) of hips and knees were assessed at baseline . Structural equation modeling was used to analyse the associations . Results : The stability of mobility performance from baseline to the five-year follow-up was high ( coefficient 0.80 in men , 0.78 in women ) . In men , knee extension strength , st and ing balance , ROM limitations and visual acuity explained 69 % of the variation in mobility performance at baseline and , indirectly , 59 % of that variation at follow-up . Among women , knee extension strength , st and ing balance , visual acuity and reaction time explained 52 % of the variation of mobility performance at baseline and , indirectly , 30 % at the five-year follow-up . Conclusions : Results indicate that the predictive effects of sensory , psychomotor and musculoskeletal functions on mobility performance extend over five years in older people . In seeking to prevent mobility limitations , vision , reaction time and lower extremity ROM need to be targeted , in addition to muscle strength and balance BACKGROUND in the primary prevention of disability among older adults it might be useful to identify individuals at high risk for functional decline before it occurs . OBJECTIVE to examine whether  tiredness in daily activities  is an independent determinant of onset of mobility disability at 1 1/2-year follow-up among non-disabled older men and women . DESIGN a prospect i ve study with 1 1/2-year follow-up . SETTING 34 communities in four counties in Denmark . SUBJECTS 1396 older non-disabled adults ( 74 - 75 and 80 years old ) living in 17 of the participating communities . METHODS question naire surveys at baseline and at 1 1/2-year follow-up . Tiredness in daily activities  was measured by questions about tiredness in six mobility activities . Onset of mobility disability was measured as onset of need for help in one to six mobility activities . RESULTS men and women who felt tired in their daily activities at baseline had a higher risk of onset of mobility disability at 1 1/2-year follow-up , when adjusted by the covariates . In addition , low social participation , poor psychological function , and physical inactivity were independent risk factors of onset of mobility disability among men , and home help , low sense of coherence and physical inactivity were independent risk factors of onset of mobility disability among women . CONCLUSION older people who complain about tiredness are at higher risk of becoming disabled than others . This highlights the need for alertness and management of this early sign of functional decline in a preventive perspective BACKGROUND numerous tests have been suggested as fall risk indicators . However , the validity of these assessment s has not been demonstrated in large representative sample s of community-dwelling older people . OBJECTIVE the objective of this study was to examine the comparative ability and clinical utility of eight mobility tests for predicting multiple falls in older community-dwelling people . METHODS design -- prospect i ve cohort study ; subjects--362 subjects aged 74 - 98 years ; measurements --the sit-to-st and test with one and five repetitions , the pick-up-weight test , the half-turn test , the alternate-step test ( AST ) , the six-metre-walk test ( SMWT )  and  stair ascent and descent tasks . Falls were monitored for 1 year with fall calendars . RESULTS in the 12-month follow-up period , 80 subjects ( 22.1 % ) suffered two or more falls . Multiple fallers 
    Output:
    