High test-retest reliability was found for the Function component , while results for the Disability component were more variable .
Conclusions There is extensive evidence to support the construct validity and sensitivity to change of the LLFDI among various clinical population s of community-dwelling older adults .
Background The choice of measure for use as a primary outcome in geriatric research is contingent upon the construct of interest and evidence for its psychometric properties .
The Late-Life Function and Disability Instrument ( LLFDI ) has been widely used to assess functional limitations and disability in studies with older adults .
The primary aim of this systematic review was to evaluate the current available evidence for the psychometric properties of the LLFDI .
Validity of an exercise test based on habitual gait speed in mobility-limited older adults.
OBJECTIVE To evaluate whether a customized exercise tolerance testing ( ETT ) protocol based on an individual 's habitual gait speed ( HGS ) on level ground would be a valid mode of exercise testing older adults . Although ETT provides a useful means to risk-stratify adults , age-related declines in gait speed paradoxically limit the utility of st and ard ETT protocol s for evaluating older adults . A customized ETT protocol may be a useful alternative to these st and ard methods , and this study hypothesized that this alternative approach would be valid . DESIGN We performed a cross-sectional analysis of baseline data from a r and omized controlled trial of older adults with observed mobility problems . Screening was performed using a treadmill-based ETT protocol customized for each individual 's HGS . We determined the content validity by assessing the results of the ETTs , and we evaluated the construct validity of treadmill time in relation to the Physical Activity Scale for the Elderly ( PASE ) and the Late Life Function and Disability Instrument ( LLFDI ) . SETTING Outpatient rehabilitation center . PARTICIPANTS Community-dwelling , mobility-limited older adults ( N=141 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Cardiac instability , ETT duration , peak heart rate , peak systolic blood pressure , PASE , and LLFDI . RESULTS Acute cardiac instability was identified in 4 of the participants who underwent ETT . The remaining participants ( n=137 , 68 % female ; mean age , 75.3 y ) were included in the subsequent analyses . Mean exercise duration was 9.39 minutes , with no significant differences in duration s being observed after evaluating among tertiles by HGS status . Mean peak heart rate and mean peak systolic blood pressure were 126.6 beats/min and 175.0 mmHg , respectively . Within separate multivariate models ,  ETT duration in each of the 3 gait speed groups was significantly associated ( P<.05 ) with PASE and LLFDI . CONCLUSIONS Mobility-limited older adults can complete this customized ETT protocol , allowing for the identification of acute cardiac instability and the achievement of optimal exercise parameters
High test-retest reliability was found for the Function component , while results for the Disability component were more variable .
Conclusions There is extensive evidence to support the construct validity and sensitivity to change of the LLFDI among various clinical population s of community-dwelling older adults .
Background The choice of measure for use as a primary outcome in geriatric research is contingent upon the construct of interest and evidence for its psychometric properties .
The Late-Life Function and Disability Instrument ( LLFDI ) has been widely used to assess functional limitations and disability in studies with older adults .
The primary aim of this systematic review was to evaluate the current available evidence for the psychometric properties of the LLFDI .