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Background: Cognitive decline may be an early indicator of major health issues in older adults, though research using population-based data is lacking. Researchers objective was to assess the relationships between distinct cognitive trajectories and subsequent health outcomes, including health status, depressive symptoms, and mortality, using a nationally representative cohort., Methods: Data were drawn from the National Health and Aging Trends Study. Global cognition was assessed annually between 2011 and 2018. The health status of 4 413 people, depressive symptoms in 4 342 individuals, and deaths among 5 955 living respondents were measured in 2019. Distinct cognitive trajectory groups were identified using an innovative Bayesian group-based trajectory model. Ordinal logistic, Poisson, and logistic regression models were used to examine the associations between cognitive trajectories and subsequent health outcomes., Results: Researchers identified five cognitive trajectory groups with distinct baseline values and subsequent changes in cognitive function. Compared with the group with stably high cognitive function, worse cognitive trajectories (ie, lower baseline values and sharper declines) were associated with higher risks of poor health status, depressive symptoms, and mortality, even after adjusting for relevant covariates., Conclusions: Among older adults, worse cognitive trajectories are strongly associated with subsequent poor health status, high depressive symptoms, and high mortality risks. Regular screening of cognitive function may help to facilitate early identification and interventions for older adults susceptible to adverse health outcomes., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Diagnosis-code-based algorithms to identify fall injuries in Medicare data are useful for ascertaining outcomes in interventional and observational studies. However, these algorithms have not been validated against a fully external reference standard, in ICD-10-CM, or in Medicare Advantage (MA) data., Methods: We linked self-reported fall injuries leading to medical attention (FIMA) from the Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) trial (reference standard) to Medicare fee-for-service (FFS) and MA data from 2015-19. We measured the area under the receiver operating characteristic curve (AUC) based on sensitivity and specificity of a diagnosis-code-based algorithm against the reference standard for presence or absence of ≥1 FIMA within a specified window of dates, varying the window size to obtain points on the curve. We stratified results by source (FFS vs MA), trial arm (intervention vs control), and STRIDE's 10 participating health care systems., Results: Both reference standard data and Medicare data were available for 4 941 (of 5 451) participants. The reference standard and algorithm identified 2 054 and 2 067 FIMA, respectively. The algorithm had 45% sensitivity (95% confidence interval [CI]: 43%-47%) and 99% specificity (95% CI: 99%-99%) to identify reference standard FIMA within the same calendar month. The AUC was 0.79 (95% CI: 0.78-0.81) and was similar by FFS or MA data source and by trial arm but showed variation among STRIDE health care systems (AUC range by health care system, 0.71 to 0.84)., Conclusions: An ICD-10-CM algorithm to identify fall injuries demonstrated acceptable performance against an external reference standard, in both MA and FFS data., (Published by Oxford University Press on behalf of The Gerontological Society of America 2024.)

Background: Despite significant support system disruptions during the coronavirus 2019 (COVID-19) pandemic, little is known about the relationship between social support and symptom burden among older adults following COVID-19 hospitalization., Methods: From a prospective cohort of 341 community-living persons aged ≥60 years hospitalized with COVID-19 between June 2020 and June 2021 who underwent follow-up at 1, 3, and 6 months after discharge, we identified 311 participants with ≥1 follow-up assessment. Social support prehospitalization was ascertained using a 5-item version of the Medical Outcomes Study Social Support Survey (range, 5-25), with low social support defined as a score ≤15. At hospitalization and each follow-up assessment, 14 physical symptoms were assessed using a modified Edmonton Symptom Assessment System inclusive of COVID-19-relevant symptoms. Mental health symptoms were assessed using Patient Health Questionnaire-4. Longitudinal associations between social support and physical and mental health symptoms, respectively, were evaluated through multivariable regression., Results: Participants' mean age was 71.3 years (standard deviation, 8.5), 52.4% were female, and 34.2% were of Black race or Hispanic ethnicity. 11.8% reported low social support. Over the 6-month follow-up period, low social support was independently associated with higher burden of physical symptoms (adjusted rate ratio [aRR], 1.26; 95% confidence interval [CI], 1.05-1.52), but not mental health symptoms (aRR, 1.14; 95% CI, 0.85-1.53)., Conclusions: Low social support is associated with greater physical, but not mental health, symptom burden among older survivors of COVID-19 hospitalization. Our findings suggest a potential need for social support screening and interventions to improve post-COVID-19 symptom management in this vulnerable group., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: It is currently unclear whether (and when) physical function exhibits a terminal decline phase, that is, a substantial acceleration of decline in the very last years before death., Methods: 702 deceased adults aged 70 years and older from the Yale PEP Study provided 4 133 measurements of physical function (Short Physical Performance Battery, SPPB) up to 20 years before death. In addition, continuous gait and chair rise subtest scores (in seconds) were assessed. Generalized mixed regression models with random change points were used to estimate the onset and the steepness of terminal decline in physical function., Results: Decline accelerated in the last years of life in all 3 measures of physical function. The onset of terminal decline occurred 1 year before death for the SPPB, and at 2.5 and 2.6 years before death for chair rise and gait speed test scores, respectively. Terminal declines in physical function were 6-8 times steeper than pre-terminal declines. Relative to those whose condition leading to death was frailty, participants who died from dementia and cancer had an up to 6 months earlier and 3 months later onset of terminal decline in SPPB, respectively., Conclusions: Terminal decline in physical function among older adults is comparable to the more established terminal decline phenomenon in cognition. Our results provide additional evidence of late-life rapid decline in physical function due to impending death., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Gerontological Society of America.)

Background: Early detection of mobility decline is critical to prevent subsequent reductions in quality of life, disability, and mortality. However, traditional approaches to mobility assessment are limited in their ability to capture daily fluctuations that align with sporadic health events. We aim to describe findings from a pilot study of our Real-time Online Assessment and Mobility Monitor (ROAMM) smartwatch application, which uniquely captures multiple streams of data in real time in ecological settings., Methods: Data come from a sample of 31 participants (Mage = 74.7, 51.6% female) who used ROAMM for approximately 2 weeks. We describe the usability and feasibility of ROAMM, summarize prompt data using descriptive metrics, and compare prompt data with traditional survey-based questionnaires or other established measures., Results: Participants were satisfied with ROAMM's function (87.1%) and ranked the usability as "above average." Most were highly engaged (average adjusted compliance = 70.7%) and the majority reported being "likely" to enroll in a 2-year study (77.4%). Some smartwatch features were correlated with their respective traditional measurements (eg, certain GPS-derived life-space mobility features (r = 0.50-0.51, p < .05) and ecologically measured pain (r = 0.72, p = .01), but others were not (eg, ecologically measured fatigue)., Conclusions: ROAMM was usable, acceptable, and effective at measuring mobility and risk factors for mobility decline in our pilot sample. Additional work with a larger and more diverse sample is necessary to confirm associations between smartwatch-measured features and traditional measures. By monitoring multiple data streams simultaneously in ecological settings, this technology could uniquely contribute to the evolution of mobility measurement and risk factors for mobility loss., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: We identify common patterns of caregiving or "care types" among older adults with and without dementia. Prior research has focused on primary caregivers and on the independent effects of individual caregiving attributes. We examine multiple caregivers of older adults, including the primary caregiver, and how multiple caregiving attributes co-occur to shape caregiving types., Methods: We link 2015 care recipient (N = 1,423) and unpaid caregiver data (N = 2,146) from the National Health and Aging Trends Study and the National Study of Caregiving. Latent class analysis of caregiving attributes, representing care intensity and regularity, and various care activities, was used to construct care types. Multinomial logistic regression was used to examine if the recipients' dementia status and caregivers' background characteristics predicted membership in care types., Results: Five distinguishable care types were identified. Caregivers who were female, adult children, or coresidents, those caring for persons with dementia, and those who had paid help had higher odds of being in the more demanding care types. Conversely, older, White caregivers and those with support for their caregiving activities were less likely to be in a demanding care type., Discussion: Care types can help us understand sources of heterogeneity in caregiving and effectively target caregiver support services and interventions., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Monitoring trajectories of intrinsic capacity (IC) in older adults has been suggested by the World Health Organization as a means to inform prevention to avoid or delay negative health outcomes. Due to a lack of longitudinal studies, it is currently unclear how IC changes over time and whether repeatedly measured IC predicts negative health outcomes., Methods: Based on 4 751 repeated observations of IC (range = 0-100) during 21 years of follow-up among 754 older adults 70 and older, we assessed longitudinal trajectories of IC, and whether time-varying IC predicted the risk of chronic activities of daily living disability, long-term nursing home stay, and mortality using joint models., Results: Average IC declined progressively from 77 to 11 points during follow-up, with substantial heterogeneity between older adults. Adjusted for sociodemographics and chronic diseases, a 1-point lower IC value was associated with a 7% increase in the risk of activities of daily living disability, a 6% increase in the risk of a nursing home stay, and a 5% increase in mortality. Accuracy for 5- and 10-year predictions based on up to 3 repeated measurements of IC ranged between moderate and good (area under the receiver operating characteristic curve = 0.76-0.82)., Conclusions: Our study indicates that IC declines progressively and that it predicts negative health outcomes among older adults. Therefore, regular monitoring of IC could work as an early warning system informing preventive efforts., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Elevated interleukine-6 (IL-6) and C-reactive protein (CRP) are associated with aging-related reductions in physical function, but little is known about their independent and combined relationships with major mobility disability (MMD), defined as the self-reported inability to walk a quarter mile., Methods: We estimated the absolute and relative effect of elevated baseline IL-6, CRP, and their combination on self-reported MMD risk among older adults (≥68 years; 59% female) with slow gait speed (<1.0 m/s). Participants were MMD-free at baseline. IL-6 and CRP were assessed using a central laboratory. The study combined a cohort of community-dwelling high-functioning older adults (Health ABC) with 2 trials of low-functioning adults at risk of MMD (LIFE-P, LIFE). Analyses utilized Poisson regression for absolute MMD incidence and proportional hazards models for relative risk., Results: We found higher MMD risk per unit increase in log IL-6 (hazard ratio [HR] = 1.26; 95% confidence interval [95% CI] 1.13-1.41). IL-6 meeting predetermined threshold considered to be high (>2.5 pg/mL) was similarly associated with higher risk of MMD (HR = 1.31; 95% CI 1.12-1.54). Elevated CRP (CRP >3.0 mg/L) was also associated with increased MMD risk (HR = 1.38; 95% CI 1.10-1.74). The CRP effect was more pronounced among participants with elevated IL-6 (HR = 1.62; 95% CI 1.12-2.33) compared to lower IL-6 levels (HR = 1.19; 95% CI 0.85-1.66)., Conclusions: High baseline IL-6 and CRP were associated with an increased risk of MMD among older adults with slow gait speed. A combined biomarker model suggests CRP was associated with MMD when IL-6 was elevated., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: This study evaluated the association between ratings of perceived exertion (RPE) of walking and major mobility disability (MMD), as well as their transitions in response to a physical activity (PA) compared to a health education (HE) program., Methods: Older adults (n = 1633) who were at risk for mobility impairment were randomized to structured PA or HE programs. During a 400 m walk, participants rated exertion as "light" or "hard." An MMD event was defined as the inability to walk 400 m. MMD events and RPE values were assessed every 6 months for an average of 2.6 years., Results: Participants rating their exertion as "hard" had a nearly threefold higher risk of MMD compared with those rating their exertion as "light" (HR: 2.61, 95% CI: 2.19-3.11). The association was held after adjusting for disease conditions, depression, cognitive function, and walking speed (HR: 2.24, 95% CI: 1.87-2.69). The PA group was 25% more likely to transition from "light" to "hard" RPE than the HE group (HR: 1.25, 95% CI: 1.05-1.49). Additionally, the PA group was 27% (HR: 0.73, 95% CI: 0.55 - 0.97) less likely to transition from a "hard" RPE to inability to walk 400 m and was more likely to recover their ability to walk 400 m by transitioning to a "hard" RPE (HR: 2.10, 95% CI: 1.39-3.17) than the HE group., Conclusions: Older adults rating "hard" effort during a standardized walk test were at increased risk of subsequent MMD. A structured PA program enabled walking recovery, but was more likely to increase transition from "light" to "hard" effort, which may reflect the greater capacity to perform the test., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Previous research suggested that there might be distinct patterns of functional decline in the last years of life depending on the condition leading to death, but the validity of these results and hence the explanatory value of the condition leading to death for late-life disability are uncertain., Methods: A total of 636 decedents from a cohort of 754 community-living persons, 70+ years of age (Yale PEP Study) provided 33 700 monthly observations of self-/proxy-reported disability during the last 5 years of life. Nonlinear trajectories and short-term fluctuations of late-life disability by condition leading to death (cancer, organ failure, frailty, severe dementia, sudden death, other) were estimated with flexible mixed spline regression models., Results: Disability trajectories at the end of life varied distinctively by the condition leading to death. Estimated disability trajectories among cancer deaths increased gradually up until about 6 months before death, after which a steep terminal decline set in. Among those with organ failure, frailty, and dementia, in contrast, disability was higher, increased more gradually, and there was no clear-cut terminal phase. Adding the condition leading to death to other known risk factors increased the amount of explained between-person variation in late-life disability from R2 = 0.35 to 0.49. Short-term fluctuations in disability were not specific for decedents with organ failure., Conclusions: The condition leading to death is an important determinant of trajectories of late-life disability. These trajectories follow distinct patterns partially resembling a previously outlined theoretical typology., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Advances in computational algorithms and the availability of large datasets with clinically relevant characteristics provide an opportunity to develop machine learning prediction models to aid in diagnosis, prognosis, and treatment of older adults. Some studies have employed machine learning methods for prediction modeling, but skepticism of these methods remains due to lack of reproducibility and difficulty in understanding the complex algorithms that underlie models. We aim to provide an overview of two common machine learning methods: decision tree and random forest. We focus on these methods because they provide a high degree of interpretability., Method: We discuss the underlying algorithms of decision tree and random forest methods and present a tutorial for developing prediction models for serious fall injury using data from the Lifestyle Interventions and Independence for Elders (LIFE) study., Results: Decision tree is a machine learning method that produces a model resembling a flow chart. Random forest consists of a collection of many decision trees whose results are aggregated. In the tutorial example, we discuss evaluation metrics and interpretation for these models. Illustrated using data from the LIFE study, prediction models for serious fall injury were moderate at best (area under the receiver operating curve of 0.54 for decision tree and 0.66 for random forest)., Conclusions: Machine learning methods offer an alternative to traditional approaches for modeling outcomes in aging, but their use should be justified and output should be carefully described. Models should be assessed by clinical experts to ensure compatibility with clinical practice., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Few studies have examined spousal influences on disability in late-life marriage, and no prior study has examined these associations using monthly data. Drawing from interdependence theory, we hypothesized that one spouse currently having higher disability would be positively associated with their partner having higher disability in the next month. We also examined whether participants were at risk for increased disability when both spouses had higher prior disability. In addition, we examined gender differences in spousal associations., Method: Data were from 37 married couples in the Precipitating Events Project, an ongoing longitudinal study of 754 initially nondisabled adults aged 70 years and older. Assessments included monthly disability (13 basic, instrumental, and mobility activities of daily living) and demographics., Results: As hypothesized, higher disability in one spouse was positively associated with higher subsequent disability in their partner. Also, wives with higher disability were especially vulnerable to subsequent increased disability when husbands had higher disability., Discussion: Incorporating a spouse's current disability level in modeling older adults' subsequent disability provides additional predictive information. Wives with greater disability may be at a particularly high risk of accelerated decline when their husbands have greater disability., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Although disability is often precipitated by an illness/injury, it may arise insidiously. Our objectives were to identify the factors associated with the development of insidious and noninsidious disability and to determine whether these risk factors differ between the two types of disability., Methods: We prospectively evaluated 754 community-living persons, 70+ years, from 1998 to 2016. The unit of analysis was an 18-month person-interval, with risk factors assessed at the start of each interval. Disability in four activities of daily living and exposure to intervening events, defined as illnesses/injuries leading to hospitalization, emergency department visits, or restricted activity, were assessed each month. Insidious and noninsidious disability were defined based on the absence and presence of an intervening event., Results: The rate of noninsidious disability (21.7%) was twice that of insidious disability (10.8%). In multivariable recurrent-event Cox analyses, six factors were associated with both disability outcomes: non-Hispanic white race, lower extremity muscle weakness, poor manual dexterity, and (most strongly) frailty, cognitive impairment, and low functional self-efficacy. Three factors were associated with only noninsidious disability (older age, number of chronic conditions, and depressive symptoms), whereas four were associated with only insidious disability (female sex, lives with others, low SPPB score, and upper extremity weakness). The modest differences in risk factors identified for the two outcomes in multivariable analyses were less apparent in the bivariate analyses., Conclusions: Although arising from different mechanisms, insidious and noninsidious disability share a similar set of risk factors. Interventions to prevent disability should prioritize this shared set of risk factors., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) may protect against aging-related decline. This study directly compared ACEis and ARBs on associations with risk of mobility disability in older adults when combined with a physical activity intervention., Methods: This was a secondary analysis of the Lifestyle Interventions and Independence for Elders (LIFE) trial. Participants aged 70-89 years were randomized to a physical activity or health education intervention. Outcomes included incident and persistent major mobility disability, injurious falls, short physical performance battery, and gait speed. For this analysis, only participants who reported ACEi or ARB use at baseline were included. Baseline differences between ACEi and ARB groups were adjusted for using inverse probability of treatment weights. Weighted Cox proportional hazard models and analysis of covariance models were used to evaluate the independent effects of medications and interaction effects with the intervention on each outcome., Results: Of 1,635 participants in the Lifestyle Interventions and Independence for Elders study, 796 used either an ACEi (496, 62.3%) or ARB (300, 37.7%). Compared with ACEi users, ARB users had 28% lower risk (hazard ratio [HR] = 0.72 [0.60-0.85]) of incident major mobility disability and 35% (HR = 0.65 [0.52-0.82]) lower risk of persistent major mobility disability whereas no interaction between medication use and intervention was observed. Risk of injurious falls and changes in short physical performance battery or gait speed were not different between ARB and ACEi users., Conclusions: These results suggest that ARBs may protect from major mobility disability by other mechanisms than improving physical performance., (© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Late-life disability is highly dynamic but within-person short-term fluctuations have not been assessed previously. We analyze how substantial such late-life disability fluctuations are and whether they are associated with time-to-death, long-term disability trajectories, frailty, and sociodemographics., Methods: Monthly survey data (Precipitating Events Project Study) on activities of daily living/instrumental activities of daily living (ADL/IADL) disability (0-9) in the last years of life from 642 deceased respondents providing 56,308 observations were analyzed with a two-step approach. Observation-level residuals extracted from a Poisson mixed regression model (first step), which depict vertical short-term fluctuations from individual long-term trajectories, were analyzed with a linear mixed regression model (second step)., Results: Short-term disability fluctuations amounted to about one ADL/IADL limitation, increased in the last 4 years of life, and were closely associated with disability increases. Associations with frailty or sociodemographics characteristics were absent except for living alone., Discussion: Short-term disability fluctuations in late life were substantial, were linked to mortality-related processes, and represent a concomitant feature of disability increases in late life., (© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Physical performance and activity have both been linked to fall risk, but the way they are jointly associated with falls is unclear. We investigated how these two factors are related to incident falls in older men., Methods: In 2,741 men (78.8 ± 5 years), we evaluated the associations between activity and physical performance and how they jointly contributed to incident falls. Activity was assessed by accelerometry. Physical performance was measured by gait speed, dynamic balance (narrow walk), chair stand time, grip strength, and leg power. Falls were ascertained by tri-annual questionnaires., Results: Men were grouped into four categories based on activity and performance levels. The greatest number of falls (36%-43%) and the highest fall rate (4.7-5.4/y among those who fell) (depending on the performance test) occurred in men with low activity/low performance, but most falls (57%-64%) and relatively high fall rates (3.0-4.35/y) occurred in the other groups (low activity/high performance, high activity/high performance and high activity/low performance; 70% of men were in these groups). There were interactions between activity, performance (gait speed, narrow walk), and incident falls (p = .001-.02); predicted falls per year were highest in men with low activity/low performance, but there was also a peak of predicted falls in those with high activity., Conclusions: In community-dwelling older men, many falls occur in those with the lowest activity/worst physical performance but fall risk is also substantial with better activity and performance. Activity/physical performance assessments may improve identification of older men at risk of falls, and allow individualized approaches to prevention., (© The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: To estimate the prevalence of disability during the last 3 years prior to death among the oldest-old (≥80 years) in China., Methods: We used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a nationally representative study of the oldest-old in China. The analytic sample included 23,934 decedents who died between 1998 and 2014 and had at least one interview within the last 3 years of life. Disability was defined as being incontinent or needing assistance in performing one or more of five other essential activities (bathing, transferring, dressing, eating, and toileting)., Results: About 57.8% (weighted) of the study decedents were female. The prevalence of disability increased modestly from 36 months to 24 months prior to death (20% to 23%), more rapidly from 24-months to 12-months before death (23% to 31%), and substantially from 12 months before death to the last month of life (31% to 48%). The disability rates were lowest for participants who died between 80 and 89 years, intermediate for those who died between 90 and 99 years, and highest for those who died at age 100 or older, although the patterns over the 3-year period were comparable for the three age groups. At each time point prior to death, a higher percentage of women was disabled than men., Conclusions: In this large nationally representative sample of the oldest-old in China, the prevalence of disability during the 3 years prior to death is high and is greater in women than men and those who die at the oldest ages.

Objectives: To investigate whether baseline social participation modifies the effect of a long-term structured physical activity (PA) program on major mobility disability (MMD)., Methods: 1,635 sedentary adults (70-89 years) with physical limitations were randomized to either a structured PA or health education (HE) intervention. Social participation was defined categorically at baseline. High social participation was defined as attending organized group functions at least once per week and visiting with noncohabitating friends and family ≥7 hr per week. Anything less was considered limited social participation. Participants performed a standardized walking test at baseline and every 6 months for up to 42 months. MMD was defined as the loss in the ability to walk 400 m., Results: There was a significant intervention by social participation interaction (p = .003). Among individuals with high levels of social participation, those randomized to PA had significantly lower incidence of MMD (hazard ratio [HR], 0.43 [95% confidence interval (CI), 0.27-0.68]; p < .01) than those randomized to HE. Individuals with limited social participation showed no mobility benefit of the PA intervention when compared with their HE counterparts (HR, 0.92 [95% CI, 0.77-1.11]; p = .40)., Discussion: Our findings suggest that baseline social participation is an important factor for the success of a PA intervention aimed at delaying mobility disability.

Background: We describe the recruitment of participants for Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE), a large pragmatic cluster randomized trial that is testing the effectiveness of a multifactorial intervention to prevent serious fall injuries. Eligible persons were 70 years or older, community-living, and at increased risk for serious fall injuries. The modified goal was to recruit 5,322 participants over 20 months from 86 primary care practices within 10 diverse health care systems across the United States., Methods: The at-risk population was identified using two distinct but complementary screening strategies that included three questions administered centrally via the mail (nine sites) or in the clinic (one site), while recruitment was completed centrally by staff at Yale., Results: For central screening, 226,603 letters mailed to 135,118 patients yielded 28,719 positive screens (12.7% of those mailed and 46.5% of the 61,729 returned). In the clinic, 22,537 screens were completed, leading to 5,732 positive screens (25.4%). Of the 34,451 patients who screened positive for high risk of serious fall injuries, 31,872 were sent a recruitment packet and, of these, 5,451 (17.1%) were enrolled over 20 months (mean age: 80 years; 62% female). The participation rate was 34.0% among eligible patients. The enrollment yields were 3.6% (vs 5% projected) for each patient screened centrally, despite multiple screens, and 10.5% (vs 33.9% projected) for each positive clinic screen., Conclusions: Despite lower-than-expected yields, the STRIDE Study exceeded its modified recruitment goal. If the STRIDE intervention is found to be effective, the two distinct strategies for identifying a high-risk population of older persons could be implemented by most health care systems.

Background: Despite the rich array of data available on seven self-care and mobility activities, a functional outcome measure, which sums the scores across these activities, has not yet been developed or validated for use in the National Health and Aging Trends Study (NHATS)., Methods: Using longitudinal data from NHATS, we evaluted 7,609 participants who were living in community settings. Development of the functional outcome measure was guided by the presence of consistent mortality gradients across a 5-category, 4-category, and two 3-category scales for each of the seven activities, whereas validation was based on predictive accuracy for mortality and concurrent change in physical performance., Results: Consistent mortality gradients were observed only for the two 3-category scales (with each activity scored as 1 [fully able/independent], 2 [vulnerable], or 4 [assistance]). Each version of the corresponding functional outcome measure, which had a range of composite scores from 7 (no disability) to 28 (highest disability), demonstrated strong predictive validity for mortality and concurrent change in physical performance, with a 2-point change being clinically meaningful. The version that defined vulnerability on the basis of accommodations, reduced activities, or difficulty, rather than difficulty alone, is preferable for use in NHATS based on a more even distribution of composite scores, a wider and more consistent mortality gradient without any mortality reversals, and slightly stronger associations with the two outcomes., Conclusions: These results provide strong, albeit preliminary evidence supporting the value of a new functional outcome measure for use in NHATS, a rich resource for investigating late-life disability.

Background: Fall injuries are a major cause of morbidity and mortality among older adults. We describe the design of a pragmatic trial to compare the effectiveness of an evidence-based, patient-centered multifactorial fall injury prevention strategy to an enhanced usual care., Methods: Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) is a 40-month cluster-randomized, parallel-group, superiority, pragmatic trial being conducted at 86 primary care practices in 10 health care systems across United States. The 86 practices were randomized to intervention or control group using covariate-based constrained randomization, stratified by health care system. Participants are community-living persons, ≥70 years, at increased risk for serious fall injuries. The intervention is a comanagement model in which a nurse Falls Care Manager performs multifactorial risk assessments, develops individualized care plans, which include surveillance, follow-up evaluation, and intervention strategies. Control group receives enhanced usual care, with clinicians and patients receiving evidence-based information on falls prevention. Primary outcome is serious fall injuries, operationalized as those leading to medical attention (nonvertebral fractures, joint dislocation, head injury, lacerations, and other major sequelae). Secondary outcomes include all fall injuries, all falls, and well-being (concern for falling; anxiety and depressive symptoms; physical function and disability). Target sample size was 5,322 participants to provide 90% power to detect 20% reduction in primary outcome rate relative to control., Results: Trial enrolled 5,451 subjects in 20 months. Intervention and follow-up are ongoing., Conclusions: The findings of the STRIDE study will have important clinical and policy implications for the prevention of fall injuries in older adults.

Background: Structured physical activity interventions delay the onset of disability for at-risk older adults. However, it is not known if at-risk older adults continue to participate in physical activity or maintain mobility benefits after cessation of structured intervention., Methods: One thousand six hundred and thirty-five sedentary men and women aged 70-89 years with Short Physical Performance Battery (SPPB) scores of 9 or less and able to walk 400 m were randomized to a structured, moderate-intensity physical activity (PA) program consisting of center-based (twice/week) and home-based (three to four times per week) aerobic, resistance, and flexibility training or a health education (HE) program combined with upper extremity stretching., Results: Most of the participants (88% of HE and 87% of PA) returned for a follow-up visit (POST) 1 year after cessation of formal intervention. The HE group reported about 1-hour less activity per week than the PA group at end of intervention (LAST TRIAL; -68.9; 95% confidence interval [CI] = -86.5 to -51.3) but similar weekly activity at POST (-13.5; 95% CI = -29.5 to 2.47). SPPB did not differ between the two groups at LAST TRIAL (-0.06; 95% CI = -0.31 to 0.19) nor POST (-0.18; 95% CI = -0.45 to 0.088)., Conclusions: Although sedentary at-risk older adults increased their physical activity during a structured physical activity intervention, they did not continue at this level following the cessation of intervention. Future exercise interventions need to include novel methods to support older adults in continued physical activity following structured interventions.

Background: The objective assessment of major mobility disability (objective MMD) by a 400-m walk test (400 MWT) is important but not always practical. Previous research on the relationship between self-reported MMD (SR MMD) and objective MMD is sparse and limited to cross-sectional data., Methods: We evaluated agreement between SR MMD and objective MMD using longitudinal data from the Lifestyle Interventions for Elders (LIFE) study. The SR MMD indices were defined based on having a lot of difficulty or inability to walk a quarter of a mile (SR-1/4MILE), walk several blocks (SR-BLOCKS), and climb one flight of stairs (SR-STAIRS)., Results: Using objective MMD as the gold standard, SR-1/4MILE and SR-BLOCKS had relatively low sensitivity (around 0.4) and high specificity (around 0.9) for prevalence. Their overall sensitivity and specificity for cumulative incident objective MMD were approximately 0.6 and 0.8, respectively. While the annual probability of staying MMD free was similar for objective MMD, SR-1/4MILE, and SR-BLOCKS (90% for all), the probability of recovering from SR MMD was higher (50%) than that of objective MMD (22%). The development of objective MMD (439 events), SR-1/4MILE (356 events), and SR-BLOCKS (379 events) had a similar trajectory over time with substantially overlapping survival curves. SR-STAIRS generally did not agree well with objective MMD. Incorporating SR-STAIRS with either SR-1/4MILE or SR-BLOCKS did not significantly improve the agreement between SR MMD and objective MMD., Conclusions: Simple SR-1/4MILE and SR-BLOCKS are reasonable candidates to define MMD if the primary outcome of interest is incident MMD.

Background: By including categories for accommodations and reduced frequency, to supplement earlier classifications of difficulty and dependence, a new 5-category functional scale has the potential to distinguish finer gradations in disability but the hierarchical nature and advantages of this scale over alternative scales are uncertain., Methods: Using data from the National Health and Aging Trends Study (N = 7,609), we conducted a series of: cross-sectional analyses that focused on the hierarchical consistency of responses in the 5-category scale; and longitudinal analyses that focused on predictive accuracy for mortality and functional dependence, comparing the 5-category scale with three simpler scales, having only three or four categories., Results: Although there was considerable variability across the seven functional activities, the prevalence of inconsistencies in the hierarchy of the 5-category scale (eg, reports difficulty but no accommodations) was relatively high. In addition, the predictive accuracy of the 5-category scale for mortality and functional dependence was only modestly better than that of the two 3-category scales and was comparable to that of the 4-category scale. Finally, when evaluated as summative disability scores, there was little difference in predictive accuracy between the 5-category scale and three alternative scales., Conclusions: Despite inconsistencies in its hierarchy, the 5-category scale is more effective in stratifying risk for mortality and functional dependence than the two 3-category scales but not the 4-category scale. When assessing changes over time, however, the addition of questions on accommodations and reduced frequency to those on difficulty and dependence, to form a summative disability score, offers little benefit and increases the burden of the assessment., (© The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Despite documented age-related declines in self-reported functional status and measured physical capacity, it is unclear whether these functional indicators follow similar trajectories over time or whether the patterns of change differ by sex., Methods: We used longitudinal data from 687 initially nondisabled adults, aged 70 or older, from the Precipitating Events Project, who were evaluated every 18 months for nearly 14 years. Self-reported disability was assessed with a 12-item disability scale. Physical capacity was measured using grip strength and a modified version of Short Physical Performance Battery. Hierarchical linear models estimated the intra-individual trajectory of each functional indicator and differences in trajectories' intercept and slope by sex., Results: Self-reported disability, grip strength, and Short Physical Performance Battery score declined over 13.5 years following nonlinear trajectories. Women experienced faster accumulation of self-reported disability, but slower declines in measured physical capacity, compared with men. Trajectory intercepts revealed that women had significantly weaker grip strength and reported higher levels of disability compared with men, with no differences in starting Short Physical Performance Battery scores. These findings were robust to adjustments for differences in sociodemographic characteristics, length-of-survival, health risk factors, and chronic-disease status., Conclusions: Despite the female disadvantage in self-reported disability, older women preserve measured physical capacity better than men over time. Self-reported and measured indicators should be viewed as complementary rather than interchangeable assessments of functional status for both clinical and research purposes, especially for sex-specific comparisons., (© The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: This subgroup analysis of the Lifestyle Intervention and Independence for Elders trial evaluates the impact of a long-term physical activity (PA) intervention on rates of major mobility disability (MMD) among older adults according to their antihypertensive medication use., Methods: Lifestyle Intervention and Independence for Elders study participants were randomized to center-based PA or health education for a median of 2.7 years. Participants were sedentary men and women aged 70-89 years with objectively measured physical limitations. This analysis evaluated rates of MMD and persistent MMD among 1,633 participants, according to antihypertensive medication use. Participants were designated as either (i) an angiotensin-converting enzyme (ACE) inhibitor user (ACEi+), (ii) a user of other antihypertensives not including ACEi (ACEi-), or (iii) nonusers of antihypertensive medications (AHT-). Interactions were explored between antihypertensive use and randomized arm., Results: Interaction terms for MMD (p = .214) and persistent MMD (p = .180) did not reach statistical significance. For MMD, PA displayed marginal effects among ACEi+ (hazard ratio [HR] = 0.76; 95% confidence interval [CI] = 0.57, 1.02) and ACEi- (HR = 0.76; 95% CI = 0.60, 0.97) but not AHT- (HR = 1.19; 95% CI = 0.75, 1.87). For persistent MMD, the effect of PA was greatest among ACEi+ (HR = 0.57; 95% CI = 0.39, 0.84) when compared to ACEi- (HR = 0.76; 95% CI = 0.55, 1.06) or AHT- (HR = 1.18; 95% CI = 0.59, 2.36)., Conclusions: The effects of long-term PA on the incidence of MMD and persistent MMD were similar among three subgroups of older adults stratified by their antihypertensive medication use. However, though statistical interactions did not reach significance, several findings may warrant future study in other cohorts given the post hoc nature of this study., (© The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Forced expiratory volume in 1 second (FEV1) over time is commonly expressed in liters and percent predicted (%Pred), or alternatively in L/m(3) and Z-scores-which approach is more clinically meaningful has not been evaluated. Because it uniquely accounts for the effect of aging on FEV1 and spirometric performance, we hypothesized that the Z-score approach is more clinically meaningful, based on associations between cardiopulmonary predictors and FEV1 over time., Methods: Using linear mixed-effects models and data from the Baltimore Longitudinal Study on Aging, including 501 white participants aged 40-95 who had completed at least three longitudinal spirometric assessments, we evaluated the associations between cardiopulmonary predictors (obesity, smoking status, hypertension, chronic bronchitis, diabetes mellitus, and myocardial infarction) and FEV1 over time, in liters, %Pred, L/m(3), and Z-scores., Results: Mean baseline values for FEV1 were 3.240L, 96.4%Pred, 0.621L/m(3), and -0.239 as a Z-score (40.6th percentile). The annual decline in FEV1 was 0.040L, 0.234 %Pred, 0.007L/m(3), and 0.008 Z-score units. Baseline age was associated with FEV1 over time in liters and L/m(3) (p < .001), and included a time interaction for %Pred (p < .001), but was not associated with Z-scores (p = .933). The associations of cardiopulmonary predictors with FEV1 over time were all significant when using Z-scores (p < .05), but varied for other methods of expressing FEV1., Conclusion: A Z-score approach is more clinically meaningful when evaluating FEV1 over time, as it accounted for the effect of aging and was more frequently associated with multiple cardiopulmonary predictors., (© The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The course of cognitive aging has demonstrated substantial heterogeneity. This study attempted to identify distinctive cognitive trajectories and examine their relationship with burdens of disability, hospitalization, and nursing home admission., Methods: Seven hundred and fifty-four community-living persons aged 70 years or older in the Yale Precipitating Events Project were assessed with the Mini-Mental State Examination every 18 months for up to 108 months. A group-based trajectory model was used to determine cognitive aging trajectories while adjusting for age, sex, and education. Cumulative burden of disabilities, hospitalizations, and nursing home admissions over 141 months associated with the cognitive trajectories were evaluated using a generalized estimating equation Poisson model., Results: Five distinct cognitive trajectories were identified, with about a third of participants starting with high baseline cognitive function and demonstrating No decline during the follow-up period. The remaining participants diverged with Minimal (prevalence 41%), Moderate (16%), Progressive (8%), and Rapid (3%) cognitive decline. Participants with No decline incurred the lowest incidence rates (per 1,000 person-months) of disability in activities of daily living (ADL; 75, 95% confidence intervals: 60-95) and instrumental ADL (492, 453-535), hospitalization (29, 26-33) and nursing home admission (18, 12-27), whereas participants on the Rapid trajectory experienced the greatest burden of ADL disability (612, 595-758) and those on the Progressive trajectory had the highest nursing home admission (363, 292-451)., Conclusions: Community-living older persons follow distinct cognitive aging trajectories and experience increasing burdens of disability, hospitalization, and nursing home placement as they age, with greater burdens for those on a declining cognitive trajectory., (© The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Losing the ability to walk safely and independently is a major concern for many older adults. The Lifestyle Interventions and Independence for Elders study recently demonstrated that a physical activity (PA) intervention can delay the onset of major mobility disability. Our objective is to examine the resources required to deliver the PA intervention and calculate the incremental cost-effectiveness compared with a health education intervention., Methods: The Lifestyle Interventions and Independence for Elders study enrolled 1,635 older adults at risk for mobility disability. They were recruited at eight field centers and randomly assigned to either PA or health education. The PA program consisted of 50-minute center-based exercise 2× weekly, augmented with home-based activity to achieve a goal of 150 min/wk of PA. Health education consisted of weekly workshops for 26 weeks, and monthly sessions thereafter. Analyses were conducted from a health system perspective, with a 2.6-year time horizon., Results: The average cost per participant over 2.6 years was US$3,302 and US$1,001 for the PA and health education interventions, respectively. PA participants accrued 0.047 per person more Quality-Adjusted Life-Years (QALYs) than health education participants. PA interventions costs were slightly higher than other recent PA interventions. The incremental cost-effectiveness ratios were US$42,376/major mobility disability prevented and US$49,167/QALY. Sensitivity analyses indicated that results were relatively robust to varied assumptions., Conclusions: The PA intervention costs and QALYs gained are comparable to those found in other studies. The ICERS are less than many commonly recommended medical treatments. Implementing the intervention in non-research settings may reduce costs further., (© The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To examine whether the age stereotypes of older individuals would become more negative or else show resiliency following stressful events and to examine whether age-stereotype negativity would increase the likelihood of experiencing a stressful event (i.e., hospitalization)., Method: Age stereotypes of 231 participants, 70 years and older, were assessed across 10 years, before and after the occurrence of hospitalizations and bereavements., Results: Age-stereotype negativity was resilient despite encountering stressful events. In contrast, more negative age stereotypes were associated with a 50% greater likelihood of experiencing a hospitalization., Discussion: The robustness of negative age stereotypes was expressed in their capacity to resist change as well as generate it., (© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: We describe the recruitment of men for The Testosterone (T) Trials, which were designed to determine the efficacy of T treatment., Methods: Men were eligible if they were ≥65 years, had an average of two morning total T values <275 ng/dL with neither value >300 ng/mL, and had symptoms and objective evidence of mobility limitation, sexual dysfunction, and/or low vitality. Men had to be eligible for and enroll in at least one of these three main trials (physical function, sexual function, vitality)., Results: Men were recruited primarily through mass mailings in 12 U.S. communities: 82% of men who contacted the sites did so in response to mailings. Men who responded were screened by telephone to ascertain eligibility. Of 51,085 telephone screens, 53.5% were eligible for further screening. Of 23,889 initial screening visits (SV1), 2,781 (11.6%) men were eligible for the second screening visit (SV2), which 2,261 (81.3%) completed. At SV2, 931 (41.2%) men met the criteria for one or more trials, the T level criterion and had no other exclusions. Of these, 790 (84.6%) were randomized; 99 (12.5%) in all three trials and 348 (44%) in two trials. Their mean age was 72 years and mean body mass index (BMI) was 31.0 kg/m(2). Mean (standard deviation) total T (ng/dL) was 212.0 (40.0)., Conclusion: Despite the telephone screening to enrollment ratio of 65 to 1, we met the recruitment goals for each trial. Recruitment of symptomatic older men with low testosterone levels is difficult but feasible., (© The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Increasing evidence suggests that illnesses and injuries leading to restricted activity have adverse functional consequences, but whether the two components of restricted activity have comparable effects is unknown. We evaluated whether an illness/injury leading to bed rest represents a more potent exposure than one leading to cutting down on one's usual activities without bed rest., Methods: We prospectively evaluated 754 community-living persons, 70+ years. Telephone interviews were completed monthly for >15 years to assess disability in four basic, five instrumental, and four mobility activities and to ascertain exposure to illnesses/injuries leading to cut down activities and bed rest, respectively. For each of the three functional domains, transitions between no disability, mild disability, and severe disability were evaluated each month., Results: For each domain, cut down activities and bed rest were significantly associated with at least one transition. The associations were consistently stronger, however, for bed rest than for cut down activities. Bed rest was a particularly potent exposure for transitions from no disability to severe disability, with hazard ratios as high as 8.94 (95% CI, 5.69-14.1) for the mobility activities, and for all transitions from severe disability (representing recovery), with hazard ratios as low as 0.25 (0.12-0.54) for the transition to no disability for the basic activities., Conclusions: In the setting of an illness/injury, bed rest was more strongly associated with a set of clinically meaningful transitions in functional status than cut down activities. Prompt medical attention may be warranted when an older person takes to bed because of an illness/injury., (© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The assessment of mobility is essential to both aging research and clinical geriatric practice. A newly developed self-report measure of mobility, the mobility assessment tool-short form (MAT-sf), uses video animations as an innovative method to improve measurement accuracy/precision. The primary aim of the current study was to evaluate whether MAT-sf scores can be used to identify risk for major mobility disability (MMD)., Methods: This article is based on data collected from the Lifestyle Interventions and Independence for Elders study and involved 1,574 older adults between the ages of 70-89. The MAT-sf was administered at baseline; MMD, operationalized as failure to complete the 400-m walk ≤ 15 minutes, was evaluated at 6-month intervals across a period of 42 months. The outcome of interest was the first occurrence of MMD or incident MMD., Results: After controlling for age, sex, clinic site, and treatment arm, baseline MAT-sf scores were found to be effective in identifying risk for MMD (p < .0001). Partitioning the MAT-sf into four groups revealed that persons with scores <40, 40-49, 50-59, and 60+ had failure rates across 42 months of follow-up of 66%, 52%, 35%, and 22%, respectively., Conclusions: The MAT-sf is a quick and efficient way of identifying older adults at risk for MMD. It could be used to clinically identify older adults that are in need of intervention for MMD and provides a simple means for monitoring the status of patients' mobility, an important dimension of functional health., (© The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The frailty syndrome is as a well-established condition of risk for disability. Aim of the study is to explore whether a physical activity (PA) intervention can reduce prevalence and severity of frailty in a community-dwelling elders at risk of disability., Methods: Exploratory analyses from the Lifestyle Interventions and Independence for Elders pilot, a randomized controlled trial enrolling 424 community-dwelling persons (mean age=76.8 years) with sedentary lifestyle and at risk of mobility disability. Participants were randomized to a 12-month PA intervention versus a successful aging education group. The frailty phenotype (ie, ≥3 of the following defining criteria: involuntary weight loss, exhaustion, sedentary behavior, slow gait speed, poor handgrip strength) was measured at baseline, 6 months, and 12 months. Repeated measures generalized linear models were conducted., Results: A significant (p = .01) difference in frailty prevalence was observed at 12 months in the PA intervention group (10.0%; 95% confidence interval = 6.5%, 15.1%), relative to the successful aging group (19.1%; 95% confidence interval = 13.9%,15.6%). Over follow-up, in comparison to successful aging participants, the mean number of frailty criteria in the PA group was notably reduced for younger subjects, blacks, participants with frailty, and those with multimorbidity. Among the frailty criteria, the sedentary behavior was the one most affected by the intervention., Conclusions: Regular PA may reduce frailty, especially in individuals at higher risk of disability. Future studies should be aimed at testing the possible benefits produced by multidomain interventions on frailty., (© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The measurement of mobility is essential to both aging research and clinical practice. A newly developed self-report measure of mobility, the mobility assessment tool-short form (MAT-sf), uses video animations to improve measurement accuracy/precision. Using a large baseline data set, we recalibrated the items, evaluated the extent to which older patients' self-efficacy (i.e., confidence) for walking was related to MAT-sf scores beyond their actual 400-m walk time, and assessed the relationship of the MAT-sf with body mass index and other clinical variables., Methods: The analyses employed baseline data from the Lifestyle Interventions and Independence for Elders Study., Results: Item recalibration demonstrated that the MAT-sf scoring algorithm was robust. In an analysis with 400-m walk time and self-efficacy regressed on the MAT-sf, both variables shared unique variance with the MAT-sf (p < .001). The MAT-sf was inversely related to several comorbidities, most notably hypertension and arthritis (p < .001), and scores were lowest when body mass index ≥ 35 kg/m(2). Finally, MAT-sf scores were directly related to Short Physical Performance Battery scores, inversely related to difficulty with activities of daily living (p < .001) and higher for men than for women (p < .001)., Conclusions: The findings extend the validity and clinical utility of this innovative tool for assessing self-reported mobility in older adults. Longitudinal data on the MAT-sf from the Lifestyle Interventions and Independence for Elders Study will enable us to evaluate the relative contributions of self-report and performance-based measures of mobility on important health outcomes.

Background: Gender-specific trajectories of lower extremity function (LEF) and the potential for bias in LEF estimation due to differences in survival have been understudied., Methods: We evaluated longitudinal data from 690 initially nondisabled adults age 70 or older from the Precipitating Events Project. LEF was assessed every 18 months for 12 years using a modified Short Physical Performance Battery (mSPPB). Hierarchical linear models with adjustments for length-of-survival estimated the intraindividual trajectory of LEF and differences in trajectory intercept and slope between men and women., Results: LEF declined following a nonlinear trajectory. In the full sample, and among participants with high (mSPPB 10-12) and intermediate (mSPPB 7-9) baseline LEF, the rate-of-decline in mSPPB was slower in women than in men, with no gender differences in baseline mSPPB scores. Among participants with low baseline LEF (mSPPB ≤6), men had a higher starting mSPPB score, whereas women experienced a deceleration in the rate-of-decline over time. In all groups, participants who survived longer had higher starting mSPPB scores and slower rates-of-decline compared with those who died sooner., Conclusions: Over the course of 12 years, older women preserve LEF better than men. Nonadjustment for differences in survival results in overestimating the level and underestimating the rate-of-decline in LEF over time.

Background: Disability is associated with depression in older persons, yet the effect of disability burden on the likelihood of being depressed is uncertain., Methods: A total of 754 community-living persons, aged ≥70, underwent monthly assessments in four essential activities of daily living and assessments of depression (yes/no) every 18 months for up to 108 months. Within each 18-month person-interval, participants' disability burden was operationalized as none or any, and according to severity (none, mild, or severe) and chronicity (none, nonchronic, or chronic) given the highest level of severity or chronicity experienced during a given 18-month interval, respectively. A variable combining severity and chronicity (none, nonchronic mild, nonchronic severe, chronic-mild, or chronic-severe) was also created. Using generalized estimating equations, we evaluated the association between each indicator of disability burden and subsequent depression., Results: Participants who had any versus no disability during the previous 18 months were 65% more likely to experience subsequent depression (OR = 1.65; 95% confidence interval [CI] 1.34, 2.02). Quantifying severity (mild disability vs. none, OR = 1.43; 95% CI: 1.15, 1.79; severe disability vs. none, OR = 2.07; 95% CI 1.56, 2.74) and chronicity (nonchronic disability vs. none, OR = 1.44; 95% CI 1.13, 1.83; chronic disability vs. none, OR = 1.96; 95% CI 1.50, 2.55) indicated increasingly stronger associations with subsequent depression, with the highest likelihood of subsequent depression (OR = 2.42; 95% CI 1.78, 3.30) observed among participants with chronic-severe disability., Conclusions: Quantifying the magnitude of disability burden, particularly on the basis of severity and chronicity, provides additional information regarding the likelihood of experiencing subsequent depression among older persons.

Background: Older persons have an increased risk of developing respiratory impairment because the aging lung is likely to have experienced exposures to environmental toxins as well as reductions in physiological capacity., Methods: Systematic review of risk factors and measures of pulmonary function that are most often considered when defining respiratory impairment in aging populations., Results: Across the adult life span, there are frequent exposures to environmental toxins, including tobacco smoke, respiratory infections, air pollution, and occupational dusts. Concurrently, there are reductions in physiological capacity that may adversely affect ventilatory control, respiratory muscle strength, respiratory mechanics, and gas exchange. Recent work has provided a strong rationale for defining respiratory impairment as an age-adjusted reduction in spirometric measures of pulmonary function that are independently associated with adverse health outcomes. Specifically, establishing respiratory impairment based on spirometric Z-scores has been shown to be strongly associated with respiratory symptoms, frailty, and mortality. Alternatively, respiratory impairment may be defined by the peak expiratory flow, as measured by a peak flow meter. The peak expiratory flow, when expressed as a Z-score, has been shown to be strongly associated with disability and mortality. However, because it has a reduced diagnostic accuracy, peak expiratory flow should only define respiratory impairment when spirometry is not readily available or an older person cannot adequately perform spirometry., Conclusions: Aging is associated with an increased risk of developing respiratory impairment, which is best defined by spirometric Z-scores. Alternatively, in selected cases, respiratory impairment may be defined by peak expiratory flow, also expressed as a Z-score.

Background: Muscle weakness and obesity are two significant threats to mobility facing the increasing number of older adults. To date, there are no studies that have examined the association of strength and body mass index (BMI) on event rates on a widely used performance measure of major mobility disability., Methods: This study was a secondary analysis of a randomized controlled trial in which sedentary functionally limited participants (70-89 years, Short Physical Performance Battery ≤ 9) who were able to complete a 400-m walk test at baseline were randomized to a physical activity or health education intervention and reassessed for major mobility disability every 6 months for up to 18 months. We evaluated whether baseline grip strength and BMI predicted failure to complete the 400-m walk test in 15 minutes or less (major mobility disability)., Results: Among N = 406 participants with baseline measures, lower grip strength was associated with an increased risk for developing major mobility disability, with and without covariate adjustment (p < .01): The hazard ratio (95% confidence interval) for the lowest versus high sex-specific quartile of grip strength was 6.11 (2.24-16.66). We observed a U-shaped relationship between baseline BMI and the risk of developing major mobility disability, such that the risk for participants with a BMI of 25-29 kg/m(2) was approximately half that of participants with BMI less than 25 or 30 kg/m(2) or more (p = .04 in fully adjusted analyses)., Conclusions: Our data highlight the importance of muscle weakness, low BMI, and obesity as risk factors for major mobility disability in older adults. Being overweight may be protective for major mobility disability.

Background: As the number of older adults in the United States rises, maintaining functional independence among older Americans has emerged as a major clinical and public health priority. Older people who lose mobility are less likely to remain in the community; demonstrate higher rates of morbidity, mortality, and hospitalizations; and experience a poorer quality of life. Several studies have shown that regular physical activity improves functional limitations and intermediate functional outcomes, but definitive evidence showing that major mobility disability can be prevented is lacking. A Phase 3 randomized controlled trial is needed to fill this evidence gap., Methods: The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase 3 multicenter randomized controlled trial designed to compare a supervised moderate-intensity physical activity program with a successful aging health education program in 1,600 sedentary older persons followed for an average of 2.7 years., Results: LIFE's primary outcome is major mobility disability, defined as the inability to walk 400 m. Secondary outcomes include cognitive function, serious fall injuries, persistent mobility disability, the combined outcome of major mobility disability or death, disability in activities of daily living, and cost-effectiveness., Conclusions: Results of this study are expected to have important public health implications for the large and growing population of older sedentary men and women.

Background: Frailty among older persons is a dynamic process, characterized by frequent transitions between frailty states over time. We performed a prospective longitudinal study to evaluate the relationship between intervening hospitalizations and these transitions., Methods: We studied 754 nondisabled community-living persons, aged 70 years or older. Frailty, assessed every 18 months for 108 months, was defined on the basis of muscle weakness, exhaustion, low physical activity, shrinking, and slow walking speed. Participants were classified as frail if they met three or more of these criteria, prefrail if they met one or two of the criteria, or nonfrail if they met none of the criteria. Hospitalizations were ascertained every month for a median of 108 months., Results: The exposure rates (95% confidence interval) of hospitalization per 1,000 months, based on frailty status at the start of each 18-month interval, were 19.7 (16.2-24.0) nonfrail, 32.9 (29.8-36.2) prefrail, and 57.2 (52.9-63.1) frail. The likelihood of transitioning from states of greater frailty to lesser frailty (ie, recovering) was consistently lower based on exposure to intervening hospitalizations, with adjusted hazard ratios per each hospitalization ranging from 0.46 (95% confidence interval: 0.21-1.03) for the transition from frail to nonfrail states to 0.52 (95% confidence interval: 0.42-0.65) for the transition from prefrail to nonfrail states. Hospitalization had more modest and less consistent effects on transitions from states of lesser frailty to greater frailty. Nonetheless, transitions from nonfrail to frail states were uncommon in the absence of a hospitalization., Conclusions: Recovery from prefrail and frail states is substantially diminished by intervening hospitalizations. These results provide additional evidence highlighting the adverse consequences of hospitalization in older persons.

Background: Longitudinal studies in gerontology are characterized by termination of measurement from death. Death is related to many important gerontological outcomes, such as functional disability, and may, over time, change the composition of an older study population. For these reasons, treating death as noninformative censoring of a longitudinal outcome may result in biased estimates of regression coefficients related to that outcome., Methods: In a longitudinal study of community-living older persons, we analytically and graphically illustrate the dependence between death and functional disability. Relative to survivors, decedents display a rapid decline of functional ability in the months preceding death. Death's strong relationship with functional disability demonstrates that death is not independent of this outcome and, hence, leads to informative censoring. We also demonstrate the "healthy survivor effect" that results from death's selection effect, with respect to functional disability, on the longitudinal makeup of an older study population., Results: We briefly survey commonly used approaches for longitudinal modeling of gerontological outcomes, with special emphasis on their treatment of death. Most common methods treat death as noninformative censoring. However, joint modeling methods are described that take into account any dependency between death and a longitudinal outcome., Conclusions: In longitudinal studies of older persons, death is often related to gerontological outcomes and, therefore, cannot be safely assumed to represent noninformative censoring. Such analyzes must account for the dependence between outcomes and death as well as the changing nature of the cohort.

Objective: We evaluated the longitudinal association between self-rated health (SRH) and timed gait, an indicator of lower extremity dysfunction, in a community-based sample of older persons., Methods: Participants (N = 754) were evaluated at 18-month intervals for 72 months. SRH was categorized as Excellent/Very Good/Good and Fair/Poor. Participants were asked to walk a 10-foot course "as fast as it feels safe and comfortable," turn around, and walk back, with timed gait defined as normal (≤10 s) or slow (>10 s). Generalized multinomial logit models, adjusted for demographic features, biomedical and psychosocial factors, and activities of daily living, evaluated the association between SRH and the likelihood of 6 possible transitions (from normal or slow timed gait to normal timed gait, slow timed gait, or death) over time. We also ran a repeated measures linear mixed model with change in timed gait as the outcome., Results: Compared with participants reporting Excellent/Very Good/Good SRH, those reporting Fair/Poor SRH were more likely to transition from normal to slow timed gait or to death. SRH was not associated with transitions from slow timed gait to normal timed gait or to death. In addition, time to complete the gait task increased (i.e., slowed) over time among participants reporting Fair/Poor SRH compared with those reporting Excellent/Very Good/Good SRH., Discussion: Among older persons, SRH is associated with the development of lower extremity dysfunction but not with recovery from lower extremity dysfunction. This relationship may indicate an intermediate step in the pathway from SRH to mortality.

Background: The objective of this study was to identify the factors associated with recovery of prehospital function among older persons admitted to a nursing home with disability after an acute hospitalization., Methods: The analytic sample included 292 participants of an ongoing cohort study who had one or more admissions to a nursing home with disability after an acute hospitalization during nearly 10 years of follow-up, yielding a total of 364 "index" nursing home admissions. Information on nursing home admissions, hospitalizations, and disability in essential activities of daily living was ascertained during monthly telephone interviews. Data on potential predictors of functional recovery were collected during comprehensive assessments, which were completed every 18 months for 90 months. Participants were considered to have recovered if they were discharged home within 6 months of their nursing home admission at (or above) their prehospital level of function., Results: Recovery of prehospital function was observed for 115 (31.6%) of the 364 index nursing home admissions. In the multivariate analysis, the strongest associations were observed for the best category of performance, relative to the poorest category, for gross motor coordination (hazard ratio [HR] 13.5, 95% confidence interval [CI] 4.02-45.0) and manual dexterity (HR 10.0, 95% CI 2.94-34.3). Only two other factors were independently associated with recovery of prehospital function: not cognitively impaired (HR 3.0, 95% CI 1.46-6.14) and no significant weight loss (HR 1.96, 95% CI 1.06-3.63)., Conclusions: In the setting of an acute hospitalization leading to a nursing home admission with disability, the likelihood of recovering prehospital function is low. The factors associated with recovery include faster performance on tests of gross motor coordination and manual dexterity and the absence of cognitive impairment and significant weight loss.

Background: Although depressive symptoms in older persons are common, their association with disability burden is not well understood. The authors evaluated the association between level of depressive symptoms and severity of subsequent disability over time and determined whether this relationship differed by sex., Methods: Participants included 754 community-living persons aged 70 years or older who underwent monthly assessments of disability in four essential activities of daily living for up to 117 months. Disability was categorized each month as none, mild, and severe. Depressive symptoms, assessed every 18 months, were categorized as low (referent group), moderate, and high. Multinomial logit models invoking Generalized Estimating Equation were used to calculate odds ratios and 95% confidence intervals., Results: Moderate (odds ratio = 1.30; 95% confidence interval: 1.18-1.43) and high (odds ratio = 1.68; 95% confidence interval: 1.50-1.88) depressive symptoms were associated with mild disability, whereas only high depressive symptoms were associated with severe disability (odds ratio = 2.05; 95% confidence interval: 1.76-2.39). Depressive symptoms were associated with disability burden in both men and women, with modest differences by sex; men had an increased likelihood of experiencing severe disability at both moderate and high levels of depressive symptoms, whereas only high depressive symptoms were associated with severe disability in women., Conclusions: Levels of depressive symptoms below the threshold for subsyndromal depression are associated with increased disability burden in older persons. Identifying and treating varying levels of depressive symptoms in older persons may ultimately help to reduce the burden of disability in this population.

Background: To advance the field of disability assessment, additional developmental work is needed. The objective of this study was to determine the potential value of participant recall when evaluating disability over discrete periods of time., Methods: We studied 491 residents of greater New Haven, Connecticut, who were 76 years old or older. Participants completed a comprehensive assessment that included several new questions on disability in four essential activities of daily living (bathing, dressing, transferring, and walking). Participants were also assessed for disability in the same activities during monthly telephone interviews before and after the comprehensive assessment. Chronic disability was defined as a new disability that was present for at least three consecutive months., Results: We found that up to half of the incident disability episodes, which would otherwise have been missed, can be ascertained if participants are asked to recall whether they have had disability "at any time" since the prior assessment; that these disability episodes, which are ascertained by participant recall, confer high risk for the subsequent development of chronic disability, with an adjusted hazard ratio of 2.5 (95% confidence interval, 1.1-5.8); and that participant recall for the absence of disability becomes increasingly inaccurate as the duration of the assessment interval increases, with 2.2%, 6.0%, 6.9%, and 9.1% of participants having inaccurate recall at 1, 3, 6, and 12 months, respectively., Conclusions: Our results demonstrate both the promise and limitations of participant recall and suggest that additional strategies are needed to more completely and accurately ascertain the occurrence of disability among older persons.

Background: Clinical trials to assess interventions for mobility disability are critically needed; however, data for efficiently designing such trials are lacking., Methods: Results are described from a pilot clinical trial in which 424 volunteers aged 70-89 years were randomly assigned to one of two interventions-physical activity or a healthy aging education program-and followed for a planned minimum of 12 months. We evaluated the longitudinal distributions of four standardized outcomes to contrast how they may serve as primary outcomes of future clinical trials: ability to walk 400 meters, ability to walk 4 meters in < or =10 seconds, a physical performance battery, and a questionnaire focused on physical function., Results: Changes in all four outcomes were interrelated over time. The ability to walk 400 meters as a dichotomous outcome provided the smallest sample size projections (i.e., appeared to be the most efficient outcome). It loaded most heavily on the underlying latent variable in structural equation modeling with a weight of 80%. A 4-year trial based on the outcome of the 400-meter walk is projected to require N = 962-2234 to detect an intervention effect of 30%-20% with 90% power., Conclusions: Future clinical trials of interventions designed to influence mobility disability may have greater efficiency if they adopt the ability to complete a 400-meter walk as their primary outcome.

Background: Peak expiratory flow ("peak flow") predicts important outcomes in older persons. Nevertheless, its clinical application is uncertain because prior strategies for reporting peak flow may not be valid. We thus determined the frequency distribution of peak flow by the conventional strategy of percent predicted (%predicted) and by an alternative method termed standardized residual (SR) percentile, and evaluated how these two metrics relate to health status in older persons., Methods: Participants included 754 community-dwelling persons aged >/= 70 years. Data included chronic conditions, frailty indicators, and peak flow., Results: Mean age was 78.4 years, with 63.7% reporting a smoking history, 17.4% chronic lung disease, and 77.1% having one or more frailty indicators. Peak flow >/= 80 %predicted was recorded in 67.5% of participants, whereas peak flow >/= 80th SR percentile was only noted in 15.9%. A graded relationship was observed between peak flow and health status, but %predicted yielded health risk at peak flows currently considered normal (80-100 %predicted), whereas SR percentile conferred health risk only at severely reduced peak flows (< 50th SR percentile)., Conclusions: Peak flow expressed as SR percentile attains a frequency distribution more consistent with the characteristics of our elderly cohort, and establishes health risk at more appropriate levels of reduced peak flow. These findings establish the need for longitudinal studies based on SR percentile to further evaluate the use of peak flow as a risk assessment tool in older persons and to determine if pulmonary function, in general, is better reported in older persons as SR percentile, rather than as %predicted.