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Background Early change in function in older adults has been termed preclinical disability (PCD). PCD has been understudied compared to other stages of disability because it is unlikely to receive comparative priority in clinical settings. It has major implications for prevention and population health as it may be the optimal time to intervene to prevent further decline. A standardized approach to research in PCD, including a common definition and measurement approaches, is needed to advance this work. Methods The process to establish how PCD should be defined and measured was undertaken in 2 stages: (1) a scoping review of the literature, which was used to inform (2) a web-enabled consensus meeting with content experts. Results The scoping review and the consensus meeting support the use of the term preclinical mobility limitation (PCML) and that it should be measured using both patient-reported and performance-based measures. It was agreed that the definition of PCML should include modification of frequency and/or method of task completion, without overt disability, and that requisite mobility tasks include walking (distance and speed), stairs, and transfers. Conclusions Currently, there are few standardized assessments that can identify PCML. PCML is the term that most clearly describes the stage where people experience a change in routine mobility tasks, without a perception of disability. Further evaluation into the reliability, validity, and responsiveness of outcome measures is needed to advance research on PCML. [ABSTRACT FROM AUTHOR]

Background: The Short Physical Performance Battery (SPPB) is advocated as a screening tool in geriatric care for predicting future disability. We aimed to identify the leg neuromuscular attributes to be targeted in rehabilitative care among older adults with poor SPPB scores.Methods: Boston Rehabilitative Impairment Study of the Elderly (Boston RISE) participants (n = 430) underwent assessment of neuromuscular attributes (leg strength, leg velocity, trunk extensor endurance, knee flexion range of motion [ROM], ankle ROM, and foot sensation). Linear regression models examined association between each neuromuscular attribute and SPPB, adjusting for age, race, gender, comorbidity, body mass index, depression, cognition, and other neuromuscular attributes.Results: Participants with 1 SD unit higher leg strength, leg velocity, and trunk extensor endurance had 0.52, 0.30, and 0.52 points higher SPPB total score. Participants with ankle ROM impairment and foot sensory loss had 0.43 and 0.57 lower SPPB total score compared with those without these. Leg strength and trunk extensor endurance were associated with balance; leg velocity, trunk extensor endurance, and ankle ROM were associated with gait speed; and strength, trunk extensor endurance, knee ROM, and feet sensation were associated with chair stand score. Neuromuscular attributes, along with covariates, explained 40.4% of the variance in the total SPPB score, a substantial increase over the 22.7% variance explained by covariates alone.Conclusions: Neuromuscular attributes affect mobility performance in older patients as measured by the SPPB. Specific impairments are associated with poor performance in specific component scores. Assessment of the SPPB components and rehabilitation of associated impairments may help improve the functional performance among older adults. [ABSTRACT FROM AUTHOR]

Background: The Late-Life Function and Disability Instrument (LLFDI) is a well-validated and frequently used patient-reported outcome for older adults. The aim of this study was to estimate the minimal clinically important difference (MCID) of the LLFDI-Function Component (LLFDI-FC) and its subscales among community-dwelling older adults with mobility limitations.Methods: We performed a secondary analysis of the Boston Rehabilitative Impairment Study of the Elderly, a longitudinal cohort study of older adults with mobility limitations residing in the community. The MCID for each LLFDI-FC scale over 1 year of follow-up was estimated using both anchor- and distribution-based methods, including mean change scores on a patient-reported global rating of change in function scale, the standard error of measurement (SEM), and the minimal detectable change with 90% confidence (MDC90).Results: Data from 320 older adults were used in the analysis (mean age 76 years, 69% female, mean of four chronic conditions). Meaningful change estimates for "small change" based on the global rating of change and SEM were 2, 3, 4, and 4 points for the LLFDI-FC overall function scale and basic lower-extremity, advanced lower-extremity, and upper-extremity subscales, respectively. Estimates for "substantial change" based on the global rating of change and minimal detectable change with 90% confidence were 5, 6, 9, and 10 points for the overall function scale and basic lower-extremity, advanced lower-extremity, and upper-extremity subscales, respectively.Conclusion: This study provides the first MCID estimates for the LLFDI-FC, a widely used patient-reported measure of function. These values can be used to interpret the outcomes of longitudinal investigations of functional status in similar populations of community-dwelling older adults. [ABSTRACT FROM AUTHOR]

Background: The physical impairments that affect participation in life roles among older adults have not been identified. Using the International Classification of Functioning Disability and Health as a conceptual framework, we aimed to determine the leg and trunk impairments that predict participation over 2 years, both directly and indirectly through mediation by changes in activities.Methods: We analyzed 2 years of data from the Boston Rehabilitative Impairment Study of the Elderly, a cohort study of 430 primary care patients with self-reported mobility limitation (mean age 77 years; 68% female; average of four chronic conditions). Frequency of and limitations in participation were examined using the Late-Life Disability Instrument. Baseline physical impairments included: leg strength, leg speed of movement, knee range of motion (ROM), ankle ROM, leg strength asymmetry, kyphosis, and trunk extensor endurance. Structural equation modeling with latent growth curve analysis was used to identify the impairments that predicted participation at year 2, mediated by changes in activities. Models were adjusted for baseline participation, age, and gender.Results: Leg speed and ankle ROM directly influenced participation in life roles during follow-up (βdirect = 1.39-4.53 and 4.70, respectively). Additionally, ankle ROM and trunk extensor endurance contributed indirectly to participation score at follow-up via effects on changes in activities (βindirect = -1.06 to -4.24 and 1.01 to 4.18, respectively).Conclusions: Leg speed, ankle ROM, and trunk extensor endurance are key physical impairments predicting participation in life roles in older adults. These results have implications for the development of exercise interventions to enhance participation. [ABSTRACT FROM AUTHOR]

Background. Patient-reported and performance-based measures (PBMs) are commonly used to measure physical function in studies of older adults. Selection of appropriate measures to address specific research questions is complex and requires knowledge of relevant psychometric properties.The aim of this study was to examine the predictive validity for adverse outcomes and responsiveness of a widely used patient-reported measure, the Late-Life Function and Disability Instrument (LLFDI), compared with PBMs. Methods. We analyzed 2 years of follow-up data from Boston RISE, a cohort study of 430 primary care patients aged >65 years. Logistic and linear regression models were used to examine predictive validity for adverse outcomes and effect size and minimal detectable change scores were computed to examine responsiveness. Performance-based functional measures included the Short Physical Performance Battery, 400-m walk, gait speed, and stair-climb power test. Results. The LLFDI and PBMs showed high predictive validity for poor self-rated health, hospitalizations, and disability.The LLFDI function scale was the only measure that predicted falls. Absolute effect size estimates ranged from 0.54 to 0.64 for the LLFDI and from 0.34 to 0.63 for the PBMs. From baseline to 2 years, the percentage of participants with a change > minimal detectable change was greatest for the LLFDI scales (46-59%) followed by the Short Physical Performance Battery (44%), gait speed (35%), 400-m walk (17%), and stair-climb power test (9%). Conclusions. The patient-reported LLFDI showed comparable psychometric properties to PBMs. Our findings support the use of the LLFDI as a primary outcome in gerontological research. [ABSTRACT FROM AUTHOR]

Background. Habitual gait speed (HGS) and the figure-of-8 walking test (F8WT) are measures of walking ability that have been associated with mobility outcomes and disability among older adults. Our objective was to contrast the physiologic, health, and behavioral attributes underlying performance of these two walking tests among older adults with mobility limitations. Methods. HGS and F8WT were the primary outcomes. HGS was measured as time needed to walk a 4-m straight course at usual pace from standstill position. F8WT was measured as time to walk in a figure-of-8 pattern at self-selected usual pace from standstill position. Separate multivariable linear regression models were constructed that predicted walking performance. Independent variables included physiologic, cognitive–behavioral health attributes, and demographic information. Results. Of 430 participants, 414 completed both walking tests. Participants were 67.7% female, had a mean age of 76.5±7.0 years and a mean of 4.1±2.0 chronic conditions. Mean HGS was 0.94±0.23 m/s and mean F8WT was 8.80±2.90 seconds. Within separate multivariable linear regression models (HGS: R2 = .46, pmodel < .001; F8WT: R2 = .47, pmodel < .001), attributes statistically significant within both models included: trunk extension endurance, ankle range of motion, leg press velocity at peak power, executive function, and sensory loss. Cognitive and physiologic attributes uniquely associated with F8WT were cognitive processing speed and self-efficacy, and reaction time and heel-to-floor time. Pain and peak leg press strength were associated with only HGS. Conclusions. Both HGS and F8WT are useful tests of walking performance. Factors uniquely associated with F8WT suggest that it may be well suited for use among older adult patients with balance problems or at risk for falls. [ABSTRACT FROM PUBLISHER]

Background. Having psychometrically strong disability measures that minimize response burden is important in assessing of older adults. Methods. Using the original 48 items from the Late-Life Function and Disability Instrument and newly developed items, a 158-item Activity Limitation and a 62-item Participation Restriction item pool were developed. The item pools were administered to a convenience sample of 520 community-dwelling adults 60 years or older. Confirmatory factor analysis and item response theory were employed to identify content structure, calibrate items, and build the computer-adaptive testings (CATs). We evaluated real-data simulations of 10-item CAT subscales. We collected data from 102 older adults to validate the 10-item CATs against the Veteran’s Short Form-36 and assessed test–retest reliability in a subsample of 57 subjects. Results. Confirmatory factor analysis revealed a bifactor structure, and multi-dimensional item response theory was used to calibrate an overall Activity Limitation Scale (141 items) and an overall Participation Restriction Scale (55 items). Fit statistics were acceptable (Activity Limitation: comparative fit index = 0.95, Tucker Lewis Index = 0.95, root mean square error approximation = 0.03; Participation Restriction: comparative fit index = 0.95, Tucker Lewis Index = 0.95, root mean square error approximation = 0.05). Correlation of 10-item CATs with full item banks were substantial (Activity Limitation: r = .90; Participation Restriction: r = .95). Test–retest reliability estimates were high (Activity Limitation: r = .85; Participation Restriction r = .80). Strength and pattern of correlations with Veteran’s Short Form-36 subscales were as hypothesized. Each CAT, on average, took 3.56 minutes to administer. Conclusions. The Late-Life Function and Disability Instrument CATs demonstrated strong reliability, validity, accuracy, and precision. The Late-Life Function and Disability Instrument CAT can achieve psychometrically sound disability assessment in older persons while reducing respondent burden. Further research is needed to assess their ability to measure change in older adults. [ABSTRACT FROM PUBLISHER]

Background. Although the notion of healthy aging has gained wide acceptance in gerontology, measuring the phenomenon is challenging. Guided by a prominent conceptualization of healthy aging, we examined how shifting from a more to less stringent definition of healthy aging influences prevalence estimates, demographic patterns, and validity. Methods. Data are from adults aged 65 years and older who participated in the Health and Retirement Study. We examined four operational definitions of healthy aging. For each, we calculated prevalence estimates and examined the odds of healthy aging by age, education, gender, and race-ethnicity in 2006. We also examined the association between healthy aging and both self-rated health and death. Results. Across definitions, the prevalence of healthy aging ranged from 3.3% to 35.5%. For all definitions, those classified as experiencing healthy aging had lower odds of fair or poor self-rated health and death over an 8-year period. The odds of being classified as “healthy” were lower among those of advanced age, those with less education, and women than for their corresponding counterparts across all definitions. Conclusions. Moving across the conceptual continuum—from a more to less rigid definition of healthy aging—markedly increases the measured prevalence of healthy aging. Importantly, results suggest that all examined definitions identified a subgroup of older adults who had substantially lower odds of reporting fair or poor health and dying over an 8-year period, providing evidence of the validity of our definitions. Conceptualizations that emphasize symptomatic disease and functional health may be particularly useful for public health purposes. [ABSTRACT FROM PUBLISHER]

Context. Testosterone in Older Men with Mobility Limitations Trial determined the effects of testosterone on muscle performance and physical function in older men with mobility limitation. Trial’s Data and Safety Monitoring Board recommended enrollment cessation due to increased frequency of adverse events in testosterone arm. The changes in muscle performance and physical function were evaluated in relation to participant’s perception of change. Methods. Men aged 65 years and older, with mobility limitation, total testosterone 100–350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Primary outcome was leg-press strength. Secondary outcomes included chest-press strength, stair-climb, 40-m walk, muscle mass, physical activity, self-reported function, and fatigue. Proportions of participants exceeding minimally important difference in study arms were compared. Results. Of 209 randomized participants, 165 had follow-up efficacy measures. Mean (SD) age was 74 (5.4) years and short physical performance battery score 7.7 (1.4). Testosterone arm exhibited greater improvements in leg-press strength, chest-press strength and power, and loaded stair-climb than placebo. Compared with placebo, significantly greater proportion of men receiving testosterone improved their leg-press and chest-press strengths (43% vs 18%, p = .01) and stair-climbing power (28% vs 10%, p = .03) more than minimally important difference. Increases in leg-press strength and stair-climbing power were associated with changes in testosterone levels and muscle mass. Physical activity, walking speed, self-reported function, and fatigue did not change. Conclusions. Testosterone administration in older men with mobility limitation was associated with patient-important improvements in muscle strength and stair-climbing power. Improvements in muscle strength and only some physical function measures should be weighed against the risk of adverse events in this population. [ABSTRACT FROM PUBLISHER]

Background: There is limited evidence supporting the hypothesized environment–disability link. The objectives of this study were to (a) identify the prevalence of community mobility barriers and transportation facilitators and (b) examine whether barriers and facilitators were associated with disability among older adults with functional limitations. Methods. Four hundred and thirty-five participants aged 65+ years old with functional limitations were recruited from the Multicenter Osteoarthritis Study, a prospective study of community-dwelling adults with or at risk of developing symptomatic knee osteoarthritis. Presence of community barriers and facilitators was ascertained by the Home and Community Environment survey. Two domains of disability, (a) daily activity limitation (DAL) and (b) daily activity frequency (DAF), were assessed with the Late-Life Disability Instrument. Covariates included age, gender, education, race, comorbidity, body mass index, knee pain, and functional limitation. Multivariable logistic regression was used to examine adjusted associations of community factors with presence of DAL and DAF. Results. Approximately one third of the participants lived in a community with high mobility barriers and low transportation facilitators. High mobility barriers was associated with greater odds of DAL (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.2–3.1) after adjusting for covariates, and high transportation facilitators was associated with lower odds of DAL (OR = 0.5, 95% CI 0.3–0.8) but not with DAF in adjusted models. Conclusion. People with functional limitations who live in communities that were more restrictive felt more limited in doing daily activities but did not perform these daily activities any less frequently. [ABSTRACT FROM PUBLISHER]

This article presents the author's views on disablement among older patients and language use in its related field of study. The author supports the development and use of a language model from World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF). The author also discusses classification frameworks for disability and the components of the ICF model.

Background. This study applied item response theory (IRT) and computer adaptive testing (CAT) methodologies to develop a prototype function and disability assessment instrument for use in aging research. Herein, we report on the development of the CAT version of the Late-Life Function and Disability Instrument (Late-Life FDI) and evaluate its psychometric properties. Methods. We used confirmatory factor analysis, IRT methods, validation, and computer simulation analyses of data collected from 67 1 older adults residing in residential care facilities. We compared accuracy, precision, and sensitivity to change of scores from CAT versions of two Late-Life FDI scales with scores from the fixed-form instrument. Score estimates from the prototype CAT versus the original instrument were compared in a sample of 40 older adults. Results. Distinct function and disability domains were identified within the Late-Life FDI item bank and used to construct two prototype CAT scales. Using retrospective data, scores from computer simulations of the prototype CAT scales were highly correlated with scores from the original instrument. The results of computer simulation, accuracy, precision, and sensitivity to change of the CATs closely approximated those of the fixed-form scales, especially for the 10- or 15-item CAT versions. In the prospective study, each CAT was administered in <3 minutes and CAT scores were highly correlated with scores generated from the original instrument. Conclusions. CAT scores of the Late-Life FDI were highly comparable to those obtained from the full-length instrument with a small loss in accuracy, precision, and sensitivity to change. [ABSTRACT FROM AUTHOR]

Part I. Focuses on a study which examined Late-Life Function and Disability Instrument designed to assess and be responsive to meaningful change in two distinct outcomes, function and disability. Methodology; Results of the study; Conclusions.

Part II. Focuses on a study which examined the developmental and evaluation of the function component of Late-life Function and Disability Instrument. Methodology; Results of the study; Conclusions.

Evaluates the degree to which existing scientific evidence supports the claimed benefits of late-life exercise as of July 2001. Importance of exercise in improving the health and well-being of a person; Categories of exercise programs examined; Exercise effects on impairment, functional limitation and disability outcomes.

Background: The literature contains few reports of the test-retest reliability of performance-based measures. The purpose of this study was to determine the test-retest reliability of a battery of seven timed, performance-based measures used to assess the functional limitations of frail, older adults.Methods: One hundred and five frail, elderly subjects were twice administered a battery of timed tests approximately 2 weeks apart: 8-foot walk, get-up-and-go test, stair climb, single and repetitive standing from a chair, and single and repetitive 10-pound lifts with the upper limbs. Agreement between the mean times recorded for accomplishing each task at the two administrations was assessed.Results: Intraclass correlation coefficients ranged from .25 for the single chair stand to .79 for the 8-foot walk. Only the time taken for the single 10-pound lift was significantly greater at the first administration as compared with the second.Conclusions: Timed performance-based measures have a wide range of test-retest reliability. Performance-based protocols that reflect familiar tasks with discrete starting and ending points may achieve higher reliability than tasks that are unfamiliar to subjects or may have ambiguous elements in them. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the articles "The Challenge of Understanding the Disablement Process in Older Persons," by J.M. Guralnik and L. Ferrucci, and "Adopting the ICF Language for Studying Late-life Disability: A Field of Dreams?" by V. Freedman.