The Dynamic Nature of Mobility Disability in Older Persons

Predicting physical functioning status in older adults: insights from wrist accelerometer sensors and derived digital biomarkers of physical activity

OBJECTIVE

Conventional physical activity (PA) metrics derived from wearable sensors may not capture the cumulative, transitions from sedentary to active, and multidimensional patterns of PA, limiting the ability to predict physical function impairment (PFI) in older adults. This study aims to identify unique temporal patterns and develop novel digital biomarkers from wrist accelerometer data for predicting PFI and its subtypes using explainable artificial intelligence techniques.

MATERIALS AND METHODS

Wrist accelerometer streaming data from 747 participants in the National Health and Aging Trends Study (NHATS) were used to calculate 231 PA features through time-series analysis techniques-Tsfresh. Predictive models for PFI and its subtypes (walking, balance, and extremity strength) were developed using 6 machine learning (ML) algorithms with hyperparameter optimization. The SHapley Additive exPlanations method was employed to interpret the ML models and rank the importance of input features.

RESULTS

Temporal analysis revealed peak PA differences between PFI and healthy controls from 9:00 to 11:00 am. The best-performing model (Gradient boosting Tree) achieved an area under the curve score of 85.93%, accuracy of 81.52%, sensitivity of 77.03%, and specificity of 87.50% when combining wrist accelerometer streaming data (WAPAS) features with demographic data.

DISCUSSION

The novel digital biomarkers, including change quantiles, Fourier transform (FFT) coefficients, and Aggregated (AGG) Linear Trend, outperformed traditional PA metrics in predicting PFI. These findings highlight the importance of capturing the multidimensional nature of PA patterns for PFI.

CONCLUSION

This study investigates the potential of wrist accelerometer digital biomarkers in predicting PFI and its subtypes in older adults. Integrated PFI monitoring systems with digital biomarkers would improve the current state of remote PFI surveillance.

Revisiting unstable disability and the fluctuations of frailty: a measurement burst approach

BACKGROUND

It has been hypothesised that frailty is the root cause of clinically observed but rarely systematically measured unstable disability among older adults. In this study, we measure the extent of short-term disability fluctuations and estimate their association with frailty using intensive longitudinal data.

METHODS

Repeated measurements of disability were collected under a measurement burst design in the FRequent health Assessment In Later life (FRAIL70+) study. A total of 426 community-dwelling older adults (70+) in Austria were interviewed about difficulties with basic, instrumental and mobility-related activities of daily living biweekly up to a total of 14 times in two measurement bursts (2891 and 2192 observations). Baseline frailty was assessed with both physical frailty (FP) and the frailty index (FI). Disability fluctuations were measured with the intra-individual interquartile range (iIQR) and estimated with a two-step generalised mixed regression procedure.

RESULTS

Fewer participants were frail at baseline according to FP (11%) than FI (32%). Frail study participants reported not only more severe disability but also had more short-term disability fluctuations (iIQR = 1.0-1.5) compared with their robust counterparts (iIQR = 0). Regression models indicated that baseline frailty was associated with 2-3 times larger short-term disability fluctuations, which were also more prevalent among women, and increased with age and disability severity.

CONCLUSION

Compared with those who were robust, frail older adults were characterised by not only more severe but also more unstable disability. Short-term disability fluctuations are closely tied to disability severity. Future studies should assess both stressors that may cause disability fluctuations among frail older adults as well as their potential consequences to inform frailty-centred care.

Factors associated with self-reports of limitations in activities of daily living among Medicare Fee-for-Service recipients

BACKGROUND

Physical function is an important indicator of physical health and predicts mortality. This study identified characteristics associated with limitations in Medicare recipients' activities of daily living.

METHODS

2019 Consumer Assessment of Healthcare Providers and Systems Fee-for-Service Medicare Survey data: 79,725 respondents (34% response rate) who were 65 and older and 53% female; 7% Black, 5% Hispanic, 4% Asian American, Native Hawaiian, or other Pacific Islander, 2% Multiracial, 1% American Indian/Alaskan Native; 35% with high school education or less. Walking, getting in and out of chairs, bathing, dressing, toileting, and eating (scored as having no difficulty versus being able to do with difficulty or unable to do) and a scale of these items were regressed on patient characteristics.

RESULTS

After adjustment for all characteristics, function limitations were found for those who smoked (effect sizes of significant associations range .04-.13), had chronic health conditions (.02-.33), were 85 years or older (.09-.46), needed assistance completing the survey (.32-1.29), were female (.05-.07), and had low income and assets (.15-.47).

CONCLUSIONS

These nationally representative U.S. estimates of physical function characteristics are useful for interventions for vulnerable population subgroups.

Developing Patient-Centered Preventative Care to Reduce Mobility Disability With Aging: Preferences From a Discrete Choice Experiment

BACKGROUND AND PURPOSE

Mobility disability is the most prevalent form of disability for older adults in the United States. A physical therapy mobility checkup (MC) under development is a patient-centered preventative physical therapy visit. It includes physical performance testing and education on physical performance as a valuable and modifiable health indicator. The purpose of this study was to identify the proportion of older adults willing to participate in an MC, the age at which they would initiate care, their desired frequency of participation, and the characteristics, or attributes, of the MC they preferred.

METHODS

In a cross-sectional study conducted at the Minnesota State Fair, adults older than 55 years answered survey questions about preventative health practices and completed a discrete choice experiment (DCE) to determine their preferences for the MC. Attributes studied in the DCE were visit duration, checkup content, education, and possible outcomes of participating in preventative care for mobility. Descriptive statistics characterized demographic information and survey responses. Conjoint choice modeling estimated the main effect for each DCE attribute.

RESULTS AND DISCUSSION

One hundred sixty-six older adults participated in the study. Seventy-eight percent indicated that they would choose an MC if available. Most participants (66%) believed that MCs should occur before 60 years of age and at least annually (68%). A 30-minute visit duration, which accounted for 84% of attribute importance, was preferred. Balance, the preferred content of the MC, accounted for 12% of the attribute importance. Preferences for educational content and possible outcomes of participation with preventative care aimed at preventing mobility loss were not statistically significant.

CONCLUSION

Older adults value preventative care for reducing mobility disability. They identified time efficiency and the inclusion of measures to assess balance as priorities for this preventative physical therapy visit.

Disability transitions in Dutch community-dwelling older people aged 75 years or older

BACKGROUND

Recent world population predictions show that the world population aged >=65 years will increase from 10% in 2022 to 16% in 2050. Population aging is accompanied by an increase in people with disability. It is important to pay special attention to people with disability, as these people are at high risk of adverse outcomes. Our study aimed to investigate the transitions of disability among Dutch community-dwelling older people aged 75 years or older, using a follow-up of nine years. We used socio-demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life events to predict the disability transitions over time.

METHODS

We used a sample of 484 people that was randomly drawn from the municipality of Roosendaal (the Netherlands), a municipality with 78,000 inhabitants. A subset of people who completed part A of the Tilburg Frailty Indicator (TFI) at baseline and the Groningen Activity Restriction Scale (GARS) questionnaires was used with a nine-year follow-up. Paired Wilcoxon tests were used to compare the consecutive measurements. Socio-demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life events were included to predict the disability transitions over time. For the univariable and multivariable analysis of the measurements over time with the predictor variables, we used generalized estimation equations (GEE). A p-value <0.05 was considered significant. R version 3.4.4 was used for all analyses.

RESULTS

Of the participants, 65% were younger than 80 years, 50% were married or cohabiting, 87% reported a healthy lifestyle, and 63% had no diseases or chronic disorders. Each year, more participants changed from status not disabled to disabled than vice versa. The GEE analyses showed that lifestyle ('not healthy') and diseases or chronic disorders ('two or more') were significant in the multivariable analysis for the disability score and only diseases or chronic disorders ('two or more') was significant in the multivariable analysis for the dichotomous disability score.

CONCLUSIONS

The transition of the disability score is strongly influenced by lifestyle and diseases or disorders. This applies to a lesser extent to the dichotomous disability score. There, only diseases or disorders are an important predictor. For health care professionals our study provides starting points for interventions focused on the prevention of worsening disability and for community-dwelling older people >= 75, the most important recommendation is: live healthy!

Group-Based Trajectory Modelling of Changes in Mobility over Six Years in Type 2 Diabetes: The Fremantle Diabetes Study Phase II

To investigate temporal changes in mobility in community-based people with type 2 diabetes, Fremantle Diabetes Study Phase II (FDS2) data were analysed. The baseline assessment included the Timed Up and Go (TUG) test, which was repeated biennially for up to six years. Group-based trajectory modelling (GBTM) identified TUG trajectory groups in participants with ≥2 tests. Independent associates of group membership were assessed using multinomial regression. Of 1551 potential FDS2 participants, 1116 (72.0%; age 64.9 ± 11.0 years, 45.6% female) were included in the modelling. The best-fitting GBTM model identified two groups with linear, minimally changing trajectories (76.2% and 19.4% of participants; baseline TUG times 8 ± 2 and 12 ± 3 s, respectively), and a third (4.5%; baseline TUG 17 ± 5 s) with a TUG that increased over time then fell at Year 6, reflecting participant attrition. Both slower groups were older, more likely to be female, obese, and had greater diabetes-associated complications and comorbidities. Almost one-quarter of the FDS2 cohort had clinically relevant mobility impairment that persisted or worsened over six years, was multifactorial in origin, and was associated with excess late withdrawals and deaths. The TUG may have important clinical utility in assessing mobility and its consequences in adults with type 2 diabetes.

Multivariate analysis of independent determinants of ADL/IADL and quality of life in the elderly

BACKGROUND

This study evaluated the determinants of disability and quality of life in elderly people who participated at the multi-centred RubiN project (Regional ununterbrochen betreut im Netz) in Germany.

METHODS

Baseline data of the subjects aged 70 years and older of the RubiN project were used and only subjects with complete data sets were considered for the ensuing analysis (complete case analysis (CCA)). Disability was examined using the concepts of ADL (activities of daily living) and IADL (instrumental activities of daily living). Subjects exhibiting one or more deficiencies in ADL respectively IADL were considered as ADL respectively IADL disabled. Quality of life was assessed using the WHOQOL-BREF and the WHOQOL-OLD. Applying multivariate analysis, sociodemographic factors, psychosocial characteristics as well as the functional, nutritional and cognitive status were explored as potential determinants of disability and quality of life in the elderly.

RESULTS

One thousand three hundred seventy-five subjects from the RubiN project exhibited data completeness regarding baseline data. ADL and IADL disability were both associated with the respective other construct of disability, sex, a reduced cognitive and functional status as well as domains of the WHOQOL-BREF. Furthermore, ADL disability was related to social participation, while IADL disability was linked to age, education and social support. Sex, ADL and IADL disability, income, social support and social participation as well as the functional status were predictors of the domain 'Physical Health' (WHOQOL-BREF). The facet 'Social Participation' (WHOQOL-OLD) was affected by both ADL and IADL disability, income, social participation, the nutritional and also the functional status.

CONCLUSIONS

Several potential determinants of disability and quality of life were identified and confirmed in this study. Attention should be drawn to prevention schemes as many of these determinants appear to be at least partly modifiable.

The association between multimorbidity and mobility disability-free life expectancy in adults aged 85 years and over: A modelling study in the Newcastle 85+ cohort

BACKGROUND

Mobility disability is predictive of further functional decline and can itself compromise older people's capacity (and preference) to live independently. The world's population is also ageing, and multimorbidity is the norm in those aged ≥85. What is unclear in this age group, is the influence of multimorbidity on (a) transitions in mobility disability and (b) mobility disability-free life expectancy (mobDFLE).

METHODS AND FINDINGS

Using multistate modelling in an inception cohort of 714 85-year-olds followed over a 10-year period (aged 85 in 2006 to 95 in 2016), we investigated the association between increasing numbers of long-term conditions and (1) mobility disability incidence, (2) recovery from mobility disability and (3) death, and then explored how this shaped the remaining life expectancy free from mobility disability at age 85. Models were adjusted for age, sex, disease group count, BMI and education. We defined mobility disability based on participants' self-reported ability to get around the house, go up and down stairs/steps, and walk at least 400 yards; participants were defined as having mobility disability if, for one or more these activities, they had any difficulty with them or could not perform them. Data were drawn from the Newcastle 85+ Study: a longitudinal population-based cohort study that recruited community-dwelling and institutionalised individuals from Newcastle upon Tyne and North Tyneside general practices. We observed that each additional disease was associated with a 16% increased risk of incident mobility disability (hazard ratio (HR) 1.16, 95% confidence interval (CI): 1.07 to 1.25, p < 0.001), a 26% decrease in the chance of recovery from this state (HR 0.74, 95% CI: 0.63 to 0.86, p < 0.001), and a 12% increased risk of death with mobility disability (HR: 1.12, 95% CI: 1.07- to .17, p < 0.001). This translated to reductions in mobDFLE with increasing numbers of long-term conditions. However, residual and unmeasured confounding cannot be excluded from these analyses, and there may have been unobserved transitions to/from mobility disability between interviews and prior to death.

CONCLUSIONS

We suggest 2 implications from this work. (1) Our findings support calls for a greater focus on the prevention of multimorbidity as populations age. (2) As more time spent with mobility disability could potentially lead to greater care needs, maintaining independence with increasing age should also be a key focus for health/social care and reablement services.

Self-reported symptom causes of mobility difficulty contributing to fear of falling in older adults

BACKGROUND

Self-reported symptom causes of mobility difficulty that contribute to  fear of falling (FOF) in older adults has not been fully explored as an area for intervention.

AIMS

Identify the prevalence of self-reported symptoms causing mobility difficulties and to examine the difference in FOF by symptom category.

METHODS

Conduct a secondary data analysis of a population-based cohort of community-dwelling older adults, ≥ 70 years, enrolled in the MOBILIZE Boston study. The analysis included 242 older adults reported difficulty walking ¼ mile (0.4 km) and/or climbing one flight of stairs. Participants identified the main symptom cause of the mobility difficulty from a list of 32 symptoms, grouped into five categories. FOF was measured using the Tinetti Falls Efficacy Scale.

RESULTS

Pain was the primary symptom causing mobility difficulty (38%), followed by endurance (21%), weakness (13%), balance (9%), and other (3%). Although a greater proportion of participants who identified balance as the primary symptom category had significantly higher FOF compared to others, there was a greater number overall who reported pain as their main symptom who also had FOF. Therefore, pain contributed to a higher relative burden of FOF in the population than did balance symptoms.

DISCUSSION

Various symptoms affect mobility and are associated with FOF, a known fall risk factor. Many older adults identify pain as the main cause of their mobility difficulty and report FOF.

CONCLUSIONS

Improving pain symptoms for older adults may improve mobility and reduce fear of falling, potentially averting further decline in mobility and independence.

Reference values of gait characteristics in community-dwelling older persons with different physical functional levels

Background

Mobility is one major component of healthy ageing of older persons. It includes gait speed, nowadays valued as the sixth vital sign of ageing. Quantitative gait analysis can support clinical diagnostics, monitor progression of diseases and provide information about the efficacy of interventions. Fast gait speed is an additional marker in the area of functional ability. Our aim was to contribute reference values of gait parameters of older persons based on their functional ability.

Methods

We visualised and combined three different established frameworks that assess gait characteristics into a new framework based approach that comprises eight gait parameters: gait speed, stride length, walk ratio, single and double support time, step width, step width CV (coefficient of variance), stride length CV. Gait parameters were stratified by two instruments that indicate levels of functional ability: First, the LUCAS Functional Ability Index (FAI), a self-administered screening tool easy to apply to a public-health orientated approach and second the Short Physical Performance Battery (SPPB), an established performance test widely used in comprehensive geriatric assessments (CGA). Gait parameters of older community-dwelling persons were measured with an objective Gait system (GAITRite) across differing functional ability ranging from robust to transient (postrobust and prefrail) to frail physical status.

Results

Of 642 community-dwelling participants (age 78.5 ± 4.8; n = 233 male, n = 409 female) categorisations by SPPB were 27.1% for robust (11–12 points), 44.2% for transient (8–10 points), 28.7% for frail (0–7 points), and 16.2, 50.3, 33.5% for robust, transient, frail by LUCAS FAI. Overall, our results showed that distinction by functional level only uncovers a wide spectrum of functional decline for all investigated gait parameters. Stratification by functional ability (biological age) revealed a greater range of differentiation than chronological age.

Conclusions

Gait parameters, carefully selected by literature, showed clinically meaningful differences between the functional featuring a gradient declining from robust over transient to frail in most gait parameters. We found discriminative power of stratifications by SPPB to be the highest, closely followed by LUCAS FAI, age groups and dichotomous age making the application of the LUCAS FAI more cost and time effective than conducting SPPB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03373-0.

Transient versus stable nature of fear of falling over 24 months in community-older persons with falls- data of the EU SCOPE project on Kidney function

BACKGROUND

Fear of falling (FoF) is an important risk factor for falls among older people. The objectives of our investigations were: a.) to present characteristics of older community-dwelling (CD) fallers with persistent or transient FoF (P-FoF or T-FoF) over 12 months, and b.) to investigate clinical predictors of P-FoF and T-FoF and c.) to explore differences between P-FoF and T-FoF.

METHODS

Our series consisted of 389 older people reporting a fall or injurious fall at baseline and during 24 months follow-up participating in a multicenter prospective study. T-FoF was defined as participants reported "not at all" at baseline and "somewhat/fairly/very concerned" at follow-up, or "not at all" at follow-up, and "somewhat/fairly/very concerned" at baseline, and P-FoF was defined as participants answered "somewhat/fairly/very concerned" in both assessments at baseline and at follow-up. The association between risk factors and T-FoF or P-FoF was investigated by logistic regression analysis.

RESULTS

The mean age of fallers in our sample was 79.0 years (SD 6.0), and 54.2% were females. Out of 389 older adults with a fall history at baseline, 83 participants (21.3%) did not report any FoF over time, P-FoF and T-FoF were observed in 42.7% and 35.9% of participants, respectively. After adjusting for potential confounders (e.g. age, gender), osteoporosis (OR = 2.04, 95%CI = 1.03-4.05) and impaired physical performance (OR = 2.38, 95%CI = 1.12-5.03) were significant predictors of T-FoF vs No-FoF. Osteoporosis (OR = 2.68, 95%CI = 1.31-5.48), depressive symptoms (OR = 3.54, 95%CI = 1.23-10.1) and living alone (OR = 2.44, 95%CI = 1.17-5.06) were significantly associated with P-FoF vs No-FoF. When comparing T-FoF and P-FoF, female gender (OR = 1.95, 95%CI = 1.16-3.27), BMI (OR = 1.08, 95%CI = 1.02-1.14), overall comorbidity (OR = 1.07, 95%CI = 1.02-1.13) and depression (OR = 2.55, 95%CI = 1.33-4.88) were significant predictors of P-FoF.

CONCLUSIONS

T-FoF and P-FoF may be predicted by different sets of risk factors among older fallers. Thus, fallers should be screened for FoF especially when carrying specific risk factors, including female gender, osteoporosis, depression, living alone, impaired physical performance, BMI, comorbidity. These findings may be helpful in designing tailored intervention to blunt the risks related to consequence of FoF among older people experiencing falls.

TRIAL REGISTRATION

The SCOPE study was registered prospectively at clinicaltrials.gov (NCT02691546; 25/02/2016).

Association of multimorbidity patterns with incident disability and recovery of independence among middle-aged and older adults

OBJECTIVE

to identify multimorbidity patterns among middle-aged and older adults in China and examine how these patterns are associated with incident disability and recovery of independence.

METHODS

data were from The China Health and Retirement Longitudinal Study. We included 14,613 persons aged ≥45 years. Latent class analysis (LCA) was conducted to identify multimorbidity patterns with clinical meaningfulness. Multinomial logistic models were used to determine the adjusted association between multimorbidity patterns and incident disability and recovery of independence.

RESULTS

we identified four multimorbidity patterns: 'low morbidity' (67.91% of the sample), 'pulmonary-digestive-rheumatic' (17.28%), 'cardiovascular-metabolic-neuro' (10.77%) and 'high morbidity' (4.04%). Compared to the 'low morbidity' group, 'high morbidity' (OR = 2.63, 95% CI = 1.97-3.51), 'pulmonary-digestive-rheumatic' (OR = 1.89, 95% CI = 1.63-2.21) and 'cardiovascular-metabolic-neuro' pattern (OR = 1.61, 95% CI = 1.31-1.97) had higher odds of incident disability in adjusted multinomial logistic models. The 'cardiovascular-metabolic-neuro' (OR = 0.60, 95% CI = 0.44-0.81), 'high morbidity' (OR = 0.68, 95% CI = 0.47-0.98) and 'pulmonary-digestive-rheumatic' group (OR = 0.75, 95% CI = 0.60-0.95) had lower odds of recovery from disability than the 'low morbidity' group. Among people without disability, the 'cardiovascular-endocrine-neuro' pattern was associated with the highest 2-year mortality (OR = 2.42, 95% CI = 1.56-3.72).

CONCLUSIONS

multimorbidity is complex and heterogeneous, but our study demonstrates that clinically meaningful patterns can be obtained using LCA. We highlight four multimorbidity patterns with differential effects on incident disability and recovery from disability. These studies suggest that targeted prevention and treatment approaches are needed for people with multimorbidity.

The effect of sex and physical frailty on incident disability after 2 years among community-dwelling older adults: KFACS study

Background

This study investigated the impact of physical frailty on the development of disabilities in mobility, activities of daily living (ADL), and instrumental activities of daily living (IADL) according to sex among community-dwelling Korean older adults.

Methods

We used data of 2,905 older adults aged 70-84 years from the Korean Frailty and Aging Cohort Study (KFACS) at baseline (2016-2017) and Wave 2 (2018-2019). Fried’s physical frailty phenotype was used to identify frailty.

Results

After adjustment, frailty showed a higher impact for women than men on developing mobility disability (odds ratio [OR]=14.00, 95% confidence interval [CI]=4.8–40.78 vs. OR=9.89, 95% CI=4.28–22.86) and IADL disability after two years (OR=7.22, 95% CI=2.67–19.56 vs. OR=3.19, 95% CI=1.17–8.70). Pre-frailty led to mobility disability for women and men (OR=2.77, 95% CI=1.93–3.98 vs. OR=2.49, 95% CI=1.66–3.72, respectively), and IADL disability only for women (OR=3.01, 95% CI=1.28–7.09). Among the IADL components, both men and women who were prefrail or frail showed increased disability in ‘using transportation’. Among men, pre-frailty was significantly associated with disability in “going out” and “shopping”. In women, frailty was significantly associated with disability in “doing laundry,” “performing household chores,” “shopping,” and “managing money”.

Conclusions

Physical frailty increased disability over 2 years for women more than men. Physical frailty increased disability in outdoor activity-related IADL components in men and household work-related IADL components in women. This study highlights the need for gender-specific policies and preventative programs for frailty, particularly restorative interventions that focus on women who are physically frail.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03263-5.

The Use of Urban Parks by Older Adults in the Context of Perceived Security

The perception of urban greenery is determined by many aspects, including the personal security of different groups of city dwellers. The objective of this study was to investigate if there are differences between the sense of security of older adults and other groups of urban park users, and which factors play an important role in the evaluation of personal security and thus determine the use (or not) of parks. A survey questionnaire was administrated to a sample of randomly selected park users in Poland (n = 394), including seniors (s = 69). The results show statistically significant differences in security perception between respondents under the age of 60 and those over the age of 60 in the case of all questioned factors. At the same time, all of them are important for a sense of security in older adults. This knowledge is crucial for designing more inclusive and age-friendly urban parks, which should meet the needs and expectations of older adults and encourage them to engage in more activity.

Variability and agreement of frailty measures and risk of falls, hospital admissions and mortality in TILDA

Little is known about the within-person variability of different frailty instruments, their agreement over time, and whether use of repeat assessments could improve the strength of associations with adverse health outcomes. Repeat measurements recorded in 2010–2011 (Wave 1) and 2012 (Wave 2) from The Irish Longitudinal Study on Ageing (TILDA) were used to classify individuals with frailty using the frailty phenotype (FP) and frailty index (FI). Within-person variability and agreement of frailty classifications were assessed using ANOVA and kappa (K) statistics, respectively. Associations of each frailty measure (wave 1, wave 2, or mean of both waves) with risk of falls, hospitalisations and all-cause mortality were assessed using logistic regression. Among 7455 individuals (mean age 64.7 [SD 9.9] years), within-person SD was 0.664 units (95% CI 0.654–0.671) for FP and 2 health deficits (SD 0.050 [0.048–0.051]) for FI. Agreement of frailty was modest for both measures, but higher for FI (K 0.600 [0.584–0.615]) than FP (K 0.370 [0.348–0.401]). The odds ratios (ORs) for all-cause mortality were higher for frailty assessed using the mean of two versus single measurements for FI (ORs for mortality 3.5 [2.6–4.9] vs. 2.7 [1.9–3.4], respectively) and FP (ORs for mortality 6.9 [4.6–10.3] vs. 4.0 [2.8–5.635], respectively). Frailty scores based on single measurements had substantial within-person variability, but the agreement in classification of frailty was higher for FI than FP. Frailty assessed using the mean of two or more measurements recorded at separate visits was more strongly associated with adverse health outcomes than those recorded at a single visit.

A Physical Therapy Mobility Checkup for Older Adults: Feasibility and Participant Preferences From a Discrete Choice Experiment

PURPOSE

Physical performance measures, like walking speed, identify and predict preclinical mobility disability but are rarely used in routine medical care. A preventive model of care called Mobility Checkup is being designed to reduce mobility disability in older adults. This study had two purposes: 1) determine feasibility and outcomes of the Mobility Checkup, and 2) identify preferences of older adults regarding this model of care using a discrete choice experiment.

METHODS

Adults over 55 years of age were recruited from the community. In the study's first phase, participants completed a Mobility Checkup, with feasibility evaluated using 6 criteria. In the second phase, a new sample of older adults (>55 years old) were educated about the Mobility Checkup and then completed a discrete choice experiment to determine their preferences regarding 4 attributes of this care model: cost, visit duration, desired education topic, and style of educational graphic.

RESULTS

Each study phase was completed by 31 participants. Of the 6 feasibility criteria, 5 were met. Visit duration exceeded the 60-minute criteria for 13 of the 31 participants. Still, 91% of participants were very satisfied with the Mobility Checkup. Ability to transition positions identified preclinical mobility disability most frequently. A 30-minute visit with no out-of-pocket cost was deemed preferred.

CONCLUSIONS

Older adults value knowing what physical performance measurements predict about their general health. Transitions should be evaluated as part of a Mobility Checkup for older adults. Clearly conveyed cost of health care service is important to older adult consumers.

Physical activity recommendation by health care providers to adults with and without functional limitations

Adults with functional limitations are more likely to be physically inactive than those without functional limitations, despite evidence that regular physical activity (PA) slows the progression of functional decline. The health care setting provides an opportunity to communicate with patients about positive behavior changes, including increased PA, but there is little information about provider recommendation for PA to adults with functional limitations. This study investigated health care provider recommendation to increase PA among adults with and without functional limitations. Adults (≥18 years) who participated in the 2016 National Health Interview Survey and reported ≥1 primary care encounter within the previous 12 months were included (unweighted n = 23,540; weighted N = 170,004,764). Receipt of PA recommendation and physical functioning limitations were self-reported. Statistical analyses were weighted to account for complex survey sampling design. One-third (35.88%) of adults received a PA recommendation and 19.71% reported functional limitations. Adults who received a PA recommendation were more likely to have a functional limitation than those who did not (28.64% vs. 14.70%; p < 0.001), even after adjusting for covariates and current activity level (aOR = 1.48; 95% CI:1.33,1.65). PA recommendation for those with functional limitations appeared to increase during middle age and peak for adults aged 65-75 years (57.01%) but declined substantially for adults ≥75 years. Only one-third of adults in the United States received PA recommendations. Health care providers recommended PA to approximately half of adults with functional limitations. Continued efforts to leverage health care encounters for behavior change should be explored, particularly for middle aged and older adults.

When Movement Moves: Study Protocol for a Multi-Method Pre/Post Evaluation Study of Two Programmes; the Danish Team Twin and Cycling Without Age

Physical activity (PA) can improve physical, mental, and social health, leading to quality of life (QoL). However, some are unable to participate independently due to age-related impairments or disabilities. This study protocol presents the design, methods, outcomes, strengths and limitations of the study “When Movement Moves” (WMM). WMM investigates whether indirect PA in a social context, where persons are unable to participate independently, can result in outcomes similar to those of independent PA, by evaluating the effects of disabled’s, elderly, volunteers’, relatives’ and nursing staff’s participation in either the running programme (Team Twin) or cycling programme (Cycling Without Age). Both programmes seek to enhance QoL through indirect PA in a social context, making PA possible for elderly and disabled persons through PA conducted by abled-bodied volunteers. WMM is a multi-method 12–16-week pre/post evaluation with quality of life, physical, mental and social health as main outcomes. Pre/post measurements consist of questionnaires, clinical examinations, and physical and cognitive appraisal. Throughout, interviews and participant observations will be conducted. Combined results will provide essential knowledge on the effects and experiences of indirect PA. Explorative data will pave the way for further research. Findings may inform policies, guidelines and health promotion among the elderly and disabled.

Predicting Future Mobility Limitation in Older Adults: A Machine Learning Analysis of Health ABC Study Data

BACKGROUND

Mobility limitation in older adults is common and associated with poor health outcomes and loss of independence. Identification of at-risk individuals remains challenging because of time-consuming clinical assessments and limitations of statistical models for dynamic outcomes over time. Therefore, we aimed to develop machine learning models for predicting future mobility limitation in older adults using repeated measures data.

METHODS

We used annual assessments over nine years of follow-up from the Health, Aging, and Body Composition study to model mobility limitation, defined as self-report of any difficulty walking a quarter mile or climbing 10 steps. We considered 46 predictors, including demographics, lifestyle, chronic conditions and physical function. With a split sample approach, we developed mixed models (generalized linear and Binary Mixed Model forest) using: 1) all 46 predictors, 2) a variable selection algorithm, and 3) the top five most important predictors. Age was included in all models. Performance was evaluated using area under the receiver operating curve (AUC) in two internal validation datasets.

RESULTS

AUC ranged from 0.80-0.84 for the models. The most important predictors of mobility limitation were ease of getting up from a chair, gait speed, self-reported health status, body mass index and depression.

CONCLUSIONS

Machine learning models using repeated measures had good performance for identifying older adults at-risk of developing mobility limitation. Future studies should evaluate the utility and efficiency of the prediction models as a tool in clinical settings for identifying at-risk older adults who may benefit from interventions aimed to prevent or delay mobility limitation.

One-Year Change in the Physical Functioning of Older People According to the International Classification of Functioning Domains

BACKGROUND AND PURPOSE

It is important to determine physical functioning declines in older people according to the International Classification of Functioning, Disability and Health (ICF) framework, given its advantages. This study was performed to investigate 1-year changes in the physical functioning of older people using the ICF framework.

METHODS

Eighty older people were enrolled and completed baseline measures in this longitudinal, single-group study while 33 of these participants were reassessed at 1 year. Reliable and valid methods commonly used in geriatric rehabilitation settings for determining physical functioning were applied to evaluate ICF domains including Body Functions, Activities (capacity), and Activities and Participation (performance). Body Functions were assessed by measuring lower extremity muscle strength and exercise tolerance test performance. The Activities (capacity) measures included walking, balance, mobility, sit-to-stand, and upper extremity functional performance. The Activities and Participation (performance) domain included the Falls Efficacy Scale-International, Modified Barthel Index, and Rapid Assessment of Physical Activity scale.

RESULTS

There were significant decreases in muscle strength in both hip abductors and knee extensors (P < .001, d > 0.80) at 1 year versus baseline, but there were no significant changes in exercise tolerance test parameters (P > .05, d = 0.44-0.71), with the exception of diastolic blood pressure (P = .019, d = 0.90). Significant deterioration was observed in all Activities (capacity) measures (P < .05, d > 0.80). No significant changes were observed in the Falls Efficacy Scale-International (P = .051, d = 0.72), Modified Barthel Index (P = .107, d = 0.59), or Rapid Assessment of Physical Activity-Flexibility and Strength subscale (P = .763, d = 0.11).

CONCLUSIONS

Significant declines were seen in lower extremity muscle strength, walking capacity, speed, mobility, sit-to-stand performance, upper extremity function, and balance performance at 1 year. On the contrary, no significant changes were observed in the levels of participation in activities of daily living, activities related to balance, or physical activity. According to the ICF framework, during 1 year, our sample of older people showed declines in the Body Functions and Activities (capacity) domains, but the Activities and Participation (performance) domain remained stable.

Effects of peri-traumatic stress experienced during Hurricane Sandy on functional limitation trajectories for older men and women

BACKGROUND AND METHODS

Although the short-term effects of disasters on the physical health of mid-life and older people have been documented, little is understood about the long-term effects that disasters have on the physical health of these people. Based on the environmental docility hypothesis and research regarding gender effects on functional limitations and disaster, our analyses examined the effects of peri-traumatic stress experienced during Hurricane Sandy using longitudinal data from 5688 people aged 50 and older collected over six waves (2006-2019).

RESULTS

We found that functional limitations follow three trajectories, with people in each group having a significant linear increase over time and all but the highest functioning people also having a significant quadratic effect, indicating that the linear increase peaked post-Hurricane and then slowed in later waves.

CONCLUSION

Consistent with the environmental docility hypothesis, peri-traumatic stress had its greatest impact on people with more functional limitations before the hurricane. Men experiencing peri-traumatic stress during Hurricane Sandy were more likely to experience an increase in functional limitations than women. These findings, which identify people most likely to experience long-term health effects following a disaster, can be used to inform health policies before, during, and after disaster strikes.

Associations of accelerometer-determined sedentary behavior and physical activity with physical performance outcomes by race/ethnicity in older women

To determine the cross-sectional associations of accelerometer-measured time spent in physical activity intensity categories (sedentary, low and high light intensity, or moderate to vigorous intensity physical activity (MVPA) with physical performance outcomes [stair climb ascent, 40 foot walk test, and short physical performance battery (SPPB)] in older women and examine differences by race/ethnicity. Data were from 1,256 Study of Women's Health Across the Nation (SWAN) participants [aged 64.9 (2.7) years at Visit 15 (2015-16); 54.1% non-White]. Three sets of adjusted multivariable linear or logistic regression models were built to test the study objectives using the backward elimination approach to identify relevant covariates. In the full analytic sample, a 10 min increment in MVPA was related to faster performance on the stair climb [β = -0.023 (95% CI: -0.04, -0.005) seconds] and 40 foot walk test [β = -0.066 (95% CI: -0.133, -0.038) seconds], and a 9% lower odds [OR: 0.91; 95% CI: 0.87, 0.96; p = 0.004] of limitations based on the SPPB. Statistically significant differences by race/ethnicity were found for the stair climb ascent time as MVPA was associated with better performance for White, Chinese, and Japanese participants while high light intensity physical activity, but not MVPA, was deemed beneficial in Black women. Findings from the isotemporal substitution models were consistent. Findings further support the importance of MVPA on physical performance outcomes in older women. Further research is needed to examine the complex associations between physical (in)activity and physical performance outcomes by race/ethnicity to provide more targeted recommendations.

Impact of Public Seating Design on Mobility and Independence of Older Adults

Background:Mobility and independence of older adults are influenced by age-related capabilities and limitations, as well as environmental factors such as non-optimum design of public seating (e.g., inappropriate seat height, angle, and compressibility as well as armrests). This study was the first part of a multi-stage investigation of the impact of public seating on older adults. Method:One hundred and six older adults (aged 65 and over) completed an online survey regarding difficulties experienced with standing up from public seating (e.g. frequency; location; type of seating; effects). Results:A majority (59.4%) reported experiencing problems, with seat height the most common issue. Shopping malls, cafes and restaurants, doctor's offices, outdoor locations, and public toilets were the most common locations. Effects included inconvenience, embarrassment, discomfort, pain, and needing help from another person to stand. Discussion:Further research is needed to explore the locations and features of seating that can contribute to this problem.

Change in Mobility: Consistency of Estimates and Predictors Across Studies of Older Adults

OBJECTIVES

This study compares estimates and determinants of within-individual changes in mobility across surveys of older U.S. adults.

METHODS

Data come from the Health and Retirement Study (HRS) and the Midlife in the United States (MIDUS) study. Measures of mobility comprise self-reported level of difficulty with walking several blocks, going up several flights of stairs, lifting and carrying 10 pounds, and stooping. Predictors include sociodemographic characteristics and indicators of health and health behaviors. We pool the datasets and estimate weighted lagged dependent variable logistic regression models for each activity, assessing cross-study differences using interaction terms between a survey indicator and relevant variables.

RESULTS

Estimates of declines in mobility differ substantially across surveys for walking, lifting and carrying, and stooping, but there are no between-survey differences in the probability of (not) recovering from a limitation. With the exception of age, determinants of change are similar between studies. For lifting/carrying and stooping, the age-related increase in developing limitations is less steep at younger ages for HRS respondents than MIDUS respondents, but steeper at older ages.

DISCUSSION

To compare estimates of mobility change across surveys, mobility measures would need to be harmonized. Determinants of mobility change, however, are more comparable.

Functional Mobility Outcomes in Telehealth and In-Person Assessments for Wheeled Mobility Devices

The purpose of this study was to compare telehealth and in-person service delivery models for wheeled mobility devices in terms of functional outcomes. We hypothesized that clinically significant improvements in functional mobility measured by the Functional Mobility Assessment (FMA) will occur in individuals receiving both telehealth and in-person clinic evaluations. A total of 27 Veterans receiving telehealth visits were compared to 27 individuals seen in clinic, selected from a database, matching for age, gender, and primary diagnosis. All mean individual item and total FMA scores in both groups increased from Time 1 to Time 2. Within the telehealth group, all changes in individual item and total FMA scores were statistically significant, with changes in 8 of 10 items meeting threshold for clinical significance (change >1.85 points). Within the clinic group, changes in 7 of 10 individual items and total FMA scores were statistically significant, and these same 7 items met threshold for clinical significance. Change scores for individual item and total FMA scores did not differ significantly between the two groups. A larger and clinically significant change in transfer score was seen in the telehealth group, suggesting telehealth visits may confer an advantage in being able to assess and address transfer issues in the home.

Is impaired dopaminergic function associated with mobility capacity in older adults?

The capacity to move is essential for independence and declines with age. Slow movement speed, in particular, is strongly associated with negative health outcomes. Prior research on mobility (herein defined as movement slowness) and aging has largely focused on musculoskeletal mechanisms and processes. More recent work has provided growing evidence for a significant role of the nervous system in contributing to reduced mobility in older adults. In this article, we report four pieces of complementary evidence from behavioral, genetic, and neuroimaging experiments that, we believe, provide theoretical support for the assertion that the basal ganglia and its dopaminergic function are responsible, in part, for age-related reductions in mobility. We report four a posteriori findings from an existing dataset: (1) slower central activation of ballistic force development is associated with worse mobility among older adults; (2) older adults with the Val/Met intermediate catecholamine-O-methyl-transferase (COMT) genotype involved in dopamine degradation exhibit greater mobility than their homozygous counterparts; (3) there are moderate relationships between performance times from a series of lower and upper extremity tasks supporting the notion that movement speed in older adults is a trait-like attribute; and (4) there is a relationship of functional connectivity within the medial orbofrontal (mOFC) cortico-striatal network and measures of mobility, suggesting that a potential neural mechanism for impaired mobility with aging is the deterioration of the integrity of key regions within the mOFC cortico-striatal network. These findings align with recent basic and clinical science work suggesting that the basal ganglia and its dopaminergic function are mechanistically linked to age-related reductions in mobility capacity.

Mobility in Older Community-Dwelling Persons: A Narrative Review

Due to the demographic changes and the increasing awareness of the role of physical function, mobility in older age is becoming an important topic. Mobility limitations have been reported as increasingly prevalent in older persons affecting about 35% of persons aged 70 and the majority of persons over 85 years. Mobility limitations have been associated with increased fall risk, hospitalization, a decreased quality of life, and even mortality. As concepts of mobility are multifactorial and complex, in this narrative review, definitions, physical factors, and their age-related changes associated with mobility will be presented. Also, areas of cognitive decline and their impact on mobility, as well as neuromuscular factors related to mobility will be addressed. Another section will relate psychological factors such as Fall-related psychological concerns and sedentary behavior to mobility. Assessment of mobility as well as effective exercise interventions are only shortly addressed. In the last part, gaps and future work on mobility in older persons are discussed.

Relative contribution of muscle strength, lean mass, and lower extremity motor function in explaining between-person variance in mobility in older adults

BACKGROUND

Approximately 35% of individuals > 70 years have mobility limitations. Historically, it was posited lean mass and muscle strength were major contributors to mobility limitations, but recent findings indicate lean mass and muscle strength only moderately explain mobility limitations. One likely reason is that lean mass and muscle strength do not necessarily incorporate measures globally reflective of motor function (defined as the ability to learn, or to demonstrate, the skillful and efficient assumption, maintenance, modification, and control of voluntary postures and movement patterns). In this study we determined the relative contribution of lean mass, muscle strength, and the four square step test, as an index of lower extremity motor function, in explaining between-participant variance in mobility tasks.

METHODS

In community-dwelling older adults (N = 89; 67% women; mean 74.9 ± 6.7 years), we quantified grip and leg extension strength, total and regional lean mass, and time to complete the four square step test. Mobility was assessed via 6-min walk gait speed, stair climb power, 5x-chair rise time, and time to complete a complex functional task. Multifactorial linear regression modeling was used to determine the relative contribution (via semi-partial r2) for indices of lean mass, indices of muscle strength, and the four square step test.

RESULTS

When aggregated by sex, the four square step test explained 17-34% of the variance for all mobility tasks (p <  0.01). Muscle strength explained ~ 12% and ~ 7% of the variance in 6-min walk gait speed and 5x-chair rise time, respectively (p <  0.02). Lean mass explained 32% and ~ 4% of the variance in stair climb power and complex functional task time, respectively (p <  0.02). When disaggregated by sex, lean mass was a stronger predictor of mobility in men.

CONCLUSION

The four square step test is uniquely associated with multiple measures of mobility in older adults, suggesting lower extremity motor function is an important factor for mobility performance.

TRIAL REGISTRATION

NCT02505529 -2015/07/22.

Understanding Health Deterioration and the Dynamic Relationship between Physical Ability and Cognition among a Cohort of Danish Nonagenarians

This study aims to determine how demographics, socioeconomic characteristics, and lifestyle affect physical and cognitive health transitions among nonagenarians, whether these transitions follow the same patterns, and how each dimension affects the transitions of the other. We applied a multistate model for panel data to 2262 individuals over a 2-year follow-up period from the 1905 Danish Cohort survey. Within two years from baseline, the transition probability from good to bad physical health-ability to stand up from a chair-was higher than dying directly (29% vs. 25%), while this was not observed for cognition (24% vs. 27%) evaluated with Mini-Mental State Examination-a score lower than 24 indicates poor cognitive health. Probability of dying either from bad physical or cognitive health condition was 50%. Health transitions were associated with sex, education, living alone, body mass index, and physical activity. Physical and cognitive indicators were associated with deterioration of cognitive and physical status, respectively, and with survivorship from a bad health condition. We conclude that physical and cognitive health deteriorated differently among nonagenarians, even if they were related to similar sociodemographic and lifestyle characteristics and resulted dynamically related with each other.

The Hierarchical Assessment of Balance and Mobility (HABAM): a useful tool to estimate length of hospital stay following hip and knee replacement

Background/Aims

The Hierarchical Assessment of Balance and Mobility is a measure of balance and mobility that can detect recovery of physical function, and can be used to identify patients at risk of delayed discharge. The aim of this study was to investigate the use of Hierarchical Assessment of Balance and Mobility scores as a predictor of length of hospital stay in patients following hip and knee replacement.

Methods

Hierarchical Assessment of Balance and Mobility scores were collected on 191 patients following primary total joint replacement. Regression and receiver operating characteristic curve analyses were conducted to assess the relationship between Hierarchical Assessment of Balance and Mobility and length of stay.

Results

Hierarchical Assessment of Balance and Mobility scores of <31 on the first post-operative day predicted longer than mean length of stay (4 days) with sensitivity and specificity of 79% and 83%. Receiver operating characteristic curve analyses showed that a Hierarchical Assessment of Balance and Mobility score of 50 was the optimal cut-off point for discharge.

Conclusions

Hierarchical Assessment of Balance and Mobility offers a practical way to quantify and objectively track patients' physical function, and can help identify patients at risk of an increased length of stay on post-operative day one.

Comparison of a Multi-Component Physical Function Battery to Usual Walking Speed for Assessing Lower Extremity Function and Mobility Limitation in Older Adults

OBJECTIVES

To compare a composite measure of physical function that comprises locomotor and non-locomotor tests (i.e., the Mobility Battery Assessment (MBA)) with traditional measures of mobility (4-m usual gait speed (UGS), six-minute walk (6MW) gait speed, and short physical performance battery (SPPB) score) for assessing lower extremity function and discriminating community dwelling older adults with and without mobility limitations.

DESIGN

Cross-sectional, observational study.

SETTING

Laboratory-based.

PARTICIPANTS

89 community-dwelling older adults (74.9±6.7).

MEASUREMENTS

Using principal component analysis we derived an MBA score for 89 community-dwelling older adults, and quantified 4-m UGS, 6MW gait speed, and SPPB score. The MBA score was based on five lab-based tests. We also quantified self-reported lower extremity function/mobility using the Neuro-QOL Lower Extremity Function-Mobility instrument. Based on this data a continuous score was derived and subjects were classified as "mobility limited" or "non-mobility limited". Correlations between the mobility measures and the Neuro-QOL score were calculated, and ROC curves were constructed to determine the AUC for the mobility measures ability to predict mobility limitations.

RESULTS

The MBA had the largest AUC (0.92) for discriminating mobility limitations and exhibited the strongest correlation (0.73) with the Neuro-QOL Lower Extremity Function-Mobility Scale. The worst performing predictors were the 4-meter UGS and stair climb power both with an AUC of 0.8 for discriminating mobility limitations, and a low correlation with Neuro-QOL Lower Extremity Function Scale of 0.39 and 0.46, respectively.

CONCLUSION

The MBA score moderately improves the magnitude of correlation and discrimination of mobility limitation in older adults than singular, standard tests of mobility.

Bone Mass and Strength and Fall-Related Fractures in Older Age

INTRODUCTION

Low bone mineral density is a risk factor for fractures. The aim of this follow-up study was to assess the association of various bone properties with fall-related fractures.

MATERIALS AND METHODS

187 healthy women aged 55 to 83 years at baseline who were either physically active or inactive were followed for 20 years. They were divided into two groups by whether or not they sustained fall-related fractures: fracture group (F) and nonfracture group (NF). At baseline, several bone properties were measured with DXA and pQCT, and their physical performance was also assessed.

RESULTS

During the follow-up, 120 women had no fall-related fractures, while 67 (38%) sustained at least one fall with fracture. NF group had about 4 to 11% greater BMD at the femoral neck and distal radius; the mean differences (95% CI) were 4.5 (0.3 to 8.6) % and 11.1 (6.3 to 16.1) %, respectively. NF group also had stronger bone structure at the tibia, the mean difference in BMC at the distal tibia was 6.0 (2.2 to 9.7) %, and at the tibial shaft 3.6 (0.4 to 6.8) %. However, there was no mean difference in physical performance.

CONCLUSIONS

Low bone properties contribute to the risk of fracture if a person falls. Therefore, in the prevention of fragility fractures, it is essential to focus on improving bone mass, density, and strength during the lifetime. Reduction of falls by improving physical performance, balance, mobility, and muscle power is equally important.

The effect of Active Plus, a computer-tailored physical activity intervention, on cognitive functioning of elderly people with chronic illness(es) - study protocol for a randomized controlled trial

BACKGROUND

Physical activity not only is beneficial to a person's health, but can also have a positive influence on cognitive functioning. However, elderly people with chronic illness(es) often do not meet the physical activity guidelines. Physical activity programs for the elderly exist, but these are often expensive and not easily accessible to the elderly with chronic illness(es). In addition, the beneficial effects of these physical activity programs on cognitive functioning have never been specifically tested in this target group. Hence, this randomized controlled trial aims to test whether Active Plus, a proven effective physical activity intervention, is able to improve the cognitive functioning of elderly people with chronic illness(es) or to slow down cognitive decline. In addition, it studies what kind of activity, intensity, duration and frequency of physical activity most strongly influence cognitive functioning.

METHODS

A randomized controlled trial is performed, comparing the Active Plus intervention group to a waiting list control group. In total 540 older adults (≥65 years) with at least one chronic illness that limits mobility are recruited from 7 municipalities. Comparable neighborhoods within a municipality are randomly allocated to the intervention or control group. Baseline and follow-up measurements after 6 and 12 months assess cognitive functioning and physical activity behavior, measured both objectively with an accelerometer and subjectively with a self-report questionnaire. Multilevel analyses are conducted to assess effects on cognitive functioning, including analyses on moderation effects for physical activity type, frequency, duration and intensity.

DISCUSSION

To our knowledge this is the first study to investigate effectiveness of a physical activity program on cognitive functioning in elderly people suffering from a broad range of chronic illnesses. If proven effective Active Plus would be a very cost effective intervention not only to increase physical activity, but also to improve cognitive functioning or slow down cognitive decline. Up till now clear evidence is lacking on the kind of physical activity, intensity, duration and frequency needed to achieve cognitive benefits. By measuring both with accelerometers and self-report questionnaires we hope to gain insight in these processes.

TRIAL REGISTRATION

Nederlands Trial Register NL6005 ; Date of Registration 21-03-2017.

The Aging Brain & the Dorsal Basal Ganglia: Implications for Age-Related Limitations of Mobility

The capacity to move is essential for independence and declines with age. Limitations in mobility impact ~35% of adults over 70 and the majority of adults over 85. These limitations are highly associated with disability, dependency, and survival. More than 25-years ago the term "sarcopenia" was coined to highlight the age-related loss of muscle mass and strength with the assumption being that sarcopenia led to limitations in mobility. However, contrary to expectations, recent findings clearly indicate these variables only modestly explain limitations in mobility. One likely reason the current sarcopenia variables of muscle mass and strength do not discriminate, or predict, mobility limitations well is because they are heavily influenced by musculoskeletal mechanisms and do not incorporate measures reflective of the central neural control of mobility. Unfortunately, the precise central neural changes associated with aging that lead to decreased mobility are poorly understood. This knowledge gap has hampered the development of effective interventions for mobility limitations and the subsequent reduction of major functional disability for older adults. Here, we discuss the potential role of the motor control circuit of the dorsal basal ganglia as well as dopaminergic function in age-related reductions in mobility.

Comparison of physical and social risk-reducing factors for the development of disability in older adults: a population-based cohort study

BACKGROUND

Considerations of modifiable risk factors for the development of disability in older age have traditionally focused on physical activity. However, there is increasing evidence that psychological, social, and cognitive factors also help to maintain functional independence. This study compared the protective associations between physical and social activities and disability onset.

METHODS

We analysed data from 5434 adults aged 50+ years tracked biennially from 2004/2005 to 2016/2017, measuring self-reported difficulty in carrying out any basic activities of daily living (ADLs) or instrumental ADLs. Exposures included mild, moderate and vigorous physical activity, frequency of socialising with friends/family, cultural engagement (eg, going to the theatre/museums/concerts), and participation in community groups.

RESULTS

Over the 12-year follow-up, 1945 adults developed disability. Using Cox proportional hazards regression models adjusted for all identified demographic and health-related variables, vigorous exercise or activity once a month or more (HR 0.82, 95% CI 0.71 to 0.96), moderate exercise or activity more than once a week (HR 0.81, 95% CI 0.67 to 0.97) or cultural engagement once or twice a year or more (HR 0.84, 95% CI 0.73 to 0.97) were associated with a lower hazard of developing disability. Other exposures did not show independent protective associations. Results were robust to sensitivity analyses considering reverse causality and exploring the potential confounding role of time-invariant factors, such as socioeconomic status.

CONCLUSION

These results suggest the importance of either developing multimodal interventions to protect against disability and promote healthy ageing or promoting greater physical and social engagement with existing community activities among older adults.

Different Cognitive Frailty Models and Health- and Cognitive-related Outcomes in Older Age: From Epidemiology to Prevention

Frailty, a critical intermediate status of the aging process that is at increased risk for negative health-related events, includes physical, cognitive, and psychosocial domains or phenotypes. Cognitive frailty is a condition recently defined by operationalized criteria describing coexisting physical frailty and mild cognitive impairment (MCI), with two proposed subtypes: potentially reversible cognitive frailty (physical frailty/MCI) and reversible cognitive frailty (physical frailty/pre-MCI subjective cognitive decline). In the present article, we reviewed the framework for the definition, different models, and the current epidemiology of cognitive frailty, also describing neurobiological mechanisms, and exploring the possible prevention of the cognitive frailty progression. Several studies suggested a relevant heterogeneity with prevalence estimates ranging 1.0–22.0% (10.7–22.0% in clinical-based settings and 1.0–4.4% in population-based settings). Cross-sectional and longitudinal population-based studies showed that different cognitive frailty models may be associated with increased risk of functional disability, worsened quality of life, hospitalization, mortality, incidence of dementia, vascular dementia, and neurocognitive disorders. The operationalization of clinical constructs based on cognitive impairment related to physical causes (physical frailty, motor function decline, or other physical factors) appears to be interesting for dementia secondary prevention given the increased risk for progression to dementia of these clinical entities. Multidomain interventions have the potential to be effective in preventing cognitive frailty. In the near future, we need to establish more reliable clinical and research criteria, using different operational definitions for frailty and cognitive impairment, and useful clinical, biological, and imaging markers to implement intervention programs targeted to improve frailty, so preventing also late-life cognitive disorders.

Assessment of physical functioning in the clinical care of the patient with advanced kidney disease

Maintenance of independent living is the top health priority among patients with advanced chronic kidney disease (CKD). Mobility limitation is often the first sign of functional limitation leading to loss of independence. Regular assessments of physical capacity can help provide kidney health providers identify patients at risk of frailty and other adverse health-related outcomes that contribute to the loss of functional independence. These physical capacities can be measured with commonly used self-reported measures of physical function or by objective physical performance testing. The current review describes commonly used assessments of self-reported physical function and physical performance. First, we describe the disablement process and how these assessments can be performed with commonly used quality of life instruments measuring self-reported physical function or objective physical performance tests. Second, we identify the determinants and correlates of self-reported physical function and physical performance and their contribution to the frailty phenotype. Third, we describe the association of physical capacities with clinical outcomes. We conclude with on possible approach to identifying and intervening on persons with CKD at high risk of functional decline.

A Comparison of Self-report Indices of Major Mobility Disability to Failure on the 400-m Walk Test: The LIFE Study

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.

DEMMI Scores, Length of Stay, and 30-Day Readmission of Acute Geriatric Patients in Denmark: A Cross-Sectional Observational Study with Longitudinal Follow-Up

The aims of this study are to describe the mobility of acute geriatric patients, the length of stay, and to characterise patients who were readmitted within 30 days based on the De Morton Mobility Index (DEMMI). A cross-sectional observational study with longitudinal follow-up was conducted in the period from 1 March 2016 to 31 August 2016. Inclusion criteria were acute geriatric patients hospitalised for a minimum of 24 h. Of the 418 patients hospitalised during the study period, 246 (59%) participated in this study (44% male, median age 83 years [70; 94]). For patients in an acute geriatric department, the median DEMMI score was 41 and the mean score was 39.95. Patients with a DEMMI score ≤40 show a significantly lower Barthel 100 index, lower 30 s. sit-to-stand scores and were significantly more likely to be bedridden or, amongst those not bedridden, to use a mobility aid. Lower DEMMI scores were associated with longer admissions. DEMMI seems to have the ability to predict discharge within one week. There was no significant association between a lower DEMMI score and higher risk for 30-day readmission. Further research is needed to determine whether the DEMMI is suitable for identifying the patient's need for further rehabilitation following the discharge.

A Longitudinal Study of Allostatic Load in Later Life: The Role of Sex, Birth Cohorts, and Risk Accumulation

Are challenging life courses associated with more wear and tear on the biological level? This study investigates this question from a life-course perspective by examining the influence of life-course risk accumulation on allostatic load (AL), considering the role of sex and birth cohorts. Using biomarker data collected over three waves (2004, 2008, and 2012) of the English Longitudinal Study of Ageing ( N = 3,824) in a growth curve framework, AL trajectories over a period of 8 years are investigated. Our results illustrate that AL increases substantially in later life. Men have higher AL than women, but increases are similar for both sexes. Older cohorts have both higher levels and a steeper increase of AL over time. Higher risk accumulation over the life course goes hand in hand with higher AL levels and steeper trajectories, contributing to the body of evidence on cumulative (dis)advantage processes in later life.

Safety and Feasibility of Dual-task Rehabilitation Program for Body Trunk Balance Using Virtual Reality and Three-dimensional Tracking Technologies

Objective

The ability to walk is one of the most important basic functional activities of daily living, and the number of patients with walking disability who need rehabilitation is increasing worldwide. The purpose of this first-in-man study was to evaluate the safety and feasibility of an off-label, tailor-made, dual-task rehabilitation program for body trunk balance using the mediVR01 system (mediVR, Inc. Osaka, Japan), which incorporates virtual reality (VR) and three-dimensional tracking technologies.

Methods

We prospectively enrolled 31 healthy volunteers to take part in the trial (Trial Registration UMIN000029659). After an assessment of body trunk balance, a tailor-made, dual-task, rehabilitation training program lasting 10-15 min was provided. The primary endpoint was the postprocedural number of simulator sickness questionnaire (SSQ) symptoms. The secondary endpoints were adverse events and satisfaction with the program.

Results

The median age of participants was 68 years, with 67.7% being elderly (>65 years) and 54.8% being male. The number of SSQ symptoms immediately after the rehabilitation programs significantly increased from 0 (interquartile range 0-0) to 0 (0-1.5) (P=0.009), with a significant difference between the young and elderly participants (P-interaction<0.001). The most frequent symptom was sweating (22.6%), followed by fatigue (19.4%). All participants successfully completed the rehabilitation programs without significant adverse events such as fall or injuries. Moreover, all participants considered the VR rehabilitation programs to be enjoyable, and 93.5% of participants reported a sense of achievement. Group attendance was associated with higher levels of satisfaction (P=0.049).

Conclusion

The tailor-made, dual-task rehabilitation training programs for body trunk balance using VR and three-dimensional tracking technologies were safe and feasible even for elderly participants.

"Taking a Turn for the Better": Does Self-reported Recovery From Walking Limitation Improve Disability and Mortality Outcomes?

Objectives

Recovery from self-reported walking limitation may be a turning point in an individual's health trajectory and may lead to better physical and mental health in the future. This research examines whether recovery from walking limitation is associated with onset of mobility disability, activities of daily living (ADLs) disability, or mortality among a national sample of older Americans.

Data and Methods

Using Waves 4 through 11 (1998-2012) of the Health and Retirement Study (HRS), discrete-time event history models (N = 12,579 person-intervals) with multiple competing events were estimated using multinomial logistic regression. The risk group was defined as respondents with walking limitation, but free of disability. A lagged measure of recovery was created using 2 adjacent waves, and disability and mortality outcomes were assessed in the subsequent wave (i.e., 2 years later).

Results

Recovery from walking limitation (i.e., difficulty walking one or several blocks) was associated with lower odds of mobility disability (i.e., difficulty walking across the room) onset, ADL with mobility disability onset, ADL without mobility disability onset, and mortality. Recovery from walking limitation was not only predictive of mobility-related outcomes, but also nonmobility-related ADLs and mortality-suggesting that the predictive capacity of recovery extends to multiple physical health outcomes.

Discussion

This research suggests that self-reported recovery from walking limitation may be a turning point in the disabling process and signals a meaningful change in an older adult's functional health trajectory.

Predicting mortality and incident immobility in older Belgian men by characteristics related to sarcopenia and frailty

There is an increasing awareness of sarcopenia in older people. We applied machine learning principles to predict mortality and incident immobility in older Belgian men through sarcopenia and frailty characteristics. Mortality could be predicted with good accuracy. Serum 25-hydroxyvitamin D and bone mineral density scores were the most important predictors.

INTRODUCTION

Machine learning principles were used to predict 5-year mortality and 3-year incident severe immobility in a population of older men by frailty and sarcopenia characteristics.

METHODS

Using prospective data from 1997 on 264 older Belgian men (n = 152 predictors), 29 statistical models were developed and tuned on 75% of data points then validated on the remaining 25%. The model with the highest test area under the curve (AUC) was chosen as the best. From these, ranked predictor importance was extracted.

RESULTS

Five-year mortality could be predicted with good accuracy (test AUC of .85 [.73; .97], sensitivity 78%, specificity 89% at a probability cut-off of 22.3%) using a Bayesian generalized linear model. Three-year incident severe immobility could be predicted with fair accuracy (test AUC .74 [.57; .91], sensitivity 67%, specificity 78% at a probability cut-off of 14.2%) using a multivariate adaptive regression splines model. Serum 25-hydroxyvitamin D levels and hip bone mineral density scores were the most important predictors of mortality, while biochemical androgen markers and Short-Form 36 Physical Domain questions were the most important predictors of immobility. Sarcopenia assessed by lean mass estimates was relevant to mortality prediction but not immobility prediction.

CONCLUSIONS

Using advanced statistical models and a machine learning approach 5-year mortality can be predicted with good accuracy using a Bayesian generalized linear model and 3-year incident severe immobility with fair accuracy using a multivariate adaptive regression splines model.

A Longitudinal Study Examining the Change in Functional Independence Over Time in Elderly Individuals With a Functioning Kidney Transplant

Background:

Functional disability is defined as the need for assistance with self-care tasks.

Objective:

To document changes in functional status over time among older prevalent renal transplant recipients.

Design:

Single center, prospective, follow-up study.

Setting:

Single center, tertiary care transplant center.

Patients:

Patients, with a functioning kidney transplant, aged 65 years or older who underwent assessment of functional status approximately 12 months previously.

Measurements:

Validated tools used included Barthel Index, the Lawton-Brody Scale of Instrumental Activities of Daily Living, the Timed Up and Go test, the Veterans Specific Activity Questionnaire, the Mini-Cog, and dynamometer handgrip strength.

Methods:

Outpatient assessment by a trained observer.

Results:

Of the 82 patients previously studied, 64 (78%) patients participated in the follow-up study (mean age 70.5 ± 4.4 years, 58% male, 55% diabetic). Among those completing functional status measures, 32 (50%) had functional disability at baseline. Over the 1-year period, 11 (17%) of these patients experienced progressive functional decline, 6 (9%) exhibited no change, and 15 (23%) had functional recovery. Eleven patients (17%) initially independent, developed new-onset disability. One of the strongest predictors of progressive functional decline was having 1 or more falls in the previous year.

Limitations:

Assessments were performed only on 2 occasions separated by approximately 1 year.

Conclusions:

Fluctuations in disability states are common among older adults living with renal transplants. Episodes of functional disability may place individuals at higher risk of persistent and/or progressive disability.

Shifting from Declines to Improvements: Associations between a Meaningful Walking Speed Change and Cognitive Evolution over Three Years in Older Adults

BACKGROUND

Although the close relationship between mobility and cognitive declines is well-known, literature has very little questioned whether improvement in walking speed over time could be associated with improvements in cognitive functions. The objective of this study was to examine the associations between a clinically meaningful improvement in walking speed and global and specific cognitive changes in older adults.

DESIGN

Prospective cohort study.

SETTING

Multidomain Alzheimer Preventive Trial (MAPT) study.

PARTICIPANTS

Three-hundred participants from the control group of the MAPT study (mean age 74.8 ± 4.2; 57% women).

MEASUREMENTS

The 4-m usual walking speed, global cognition, memory, executive functions, and processing speed measures were collected at baseline, and at 6, 12, 24 and 36 months. Participants were categorized into three groups according to their walking speed change over the three-year study: 1/ Non-Improvers (participants not presenting an increase ≥0.05m/sec on walking speed; n=138); 2/ Improvers (increase ≥0.05m/sec; n=40); Cyclic (≥0.05m/sec improvement at some time points without maintaining it through the whole period; n=122).

RESULTS

Adjusted mixed-effect linear regressions revealed that walking speed improvers did not significantly differ from participants who never or temporarily improved their walking speed on all of global and specific cognitive functions over three years. Nevertheless, a sensitivity analysis (excluding participants with a non-clinical walking speed improvement) indicated specific cognitive trajectories per group associated with better episodic memory scores for Improvers compared to non-improvers (β=2.41, 95% CI=.12 - 4.71; p=.039).

CONCLUSION

This study found that the overtime trajectories of cognitive functions did not differ as a function of clinically meaningful walking speed changes in older adults. Nevertheless, secondary analyses provided new insights on the relationship between walking speed and specific cognitive functions. The novelty of this approach (switching from declines to improvements) should be considered in future large-scale, observational longitudinal studies.

Muscle Weakness and Physical Disability in Older Americans: Longitudinal Findings from the U.S. Health and Retirement Study

IMPORTANCE

Muscle weakness is an important indicator of disability, chronic disease and mortality. While we recently proposed sex/race specific grip strength cutpoints for clinical muscle weakness in a diverse, nationally representative sample of older Americans, the extent to which these cutpoints predict physical disability remains unknown.

OBJECTIVE

To examine whether sex/race specific muscle weakness cutpoints predict physical disability status in a nationally representative sample of Americans age 65+.

DESIGN

We used data from the 2006-2010 Health and Retirement Study. Fully-adjusted, weighted multinomial logistic regression models were used to quantify the odds of experiencing the onset, progression or persistence of disability in activities of daily living (ADL) among weak versus non-weak individuals over a 2-year period.

SETTING

General community, nationally representative sample of older Americans.

PARTICIPANTS

Population-based, community dwelling sample of older American adults aged 65-years+; 57 percent were women, 91% were White and the mean age was 75 years. Main Outcome(s) and Measure(s): The primary outcome of interest was disability dynamics, defined by changes in ADL status across at 2- year period. The primary exposure was clinical muscle weakness as defined by previously identified cutpoints. Hypotheses were formulated before analyses were conducted.

RESULTS

In this nationally representative sample (n= 8,725), 44% of individuals were classified as weak at baseline. At follow-up, 55% remained independent with no change in their ADL status, 11% had an onset of disability and 4% progressed in their disability status. The odds of experiencing an onset of ADL disability was 54% higher among weak individuals compared those who were not weak at baseline (OR= 1.54, 95% CI= 1.54, 1.5, p<.0001); the odds of experiencing a progression in physical disability status was 2.16 times higher among those who were weak at baseline compared to non-weak individuals (OR= 2.16, 95% CI= 2.15, 2.16, p<.0001).

CONCLUSIONS

This is the first study to use grip strength weakness cut-points to identify those who may be at greatest risk for experiencing physical disability in later life. Results underscore the importance of using population-specific cutpoints for clinical weakness in order to identify individuals at greatest risk for adverse health outcomes.