Further Evidence for the Importance of Subclinical Functional Limitation and Subclinical Disability Assessment in Gerontology and Geriatrics

Omega-3 polyunsatured fatty acids and physical performance across the lifespan: a narrative review

Background and Aims

Physical performance is a major contributor of mobility and independence during older life. Despite a progressive decline in musculoskeletal function starts from middle age, several factors acting during the life-course can negatively influence musculoskeletal functional capacities. Lifestyle interventions incorporating nutrition and physical exercise can help maximizing the muscle functional capacities in early life as well as preserving them later in life. Among various dietary compounds, omega-3 polyunsaturated fatty acids (PUFAs) are gaining growing attention for their potential effects on muscle membrane composition and muscle function. Indeed, several pathways are enhanced, such as an attenuation of pro-inflammatory oxidative stress, mitochondrial function, activation of the mammalian target of rapamycin (mTOR) signaling and reduction of insulin resistance.

Methods

We performed a narrative review to explore the existing literature on the relationship between omega-3 PUFAs and physical performance across the life-course.

Results

Growing evidence from randomized controlled trials (RCTs) suggests beneficial effects of omega-3 PUFAs on muscle function, including physical performance parameters in mid to later life. On the other hand, despite a direct association in early life is not available in literature, some mechanisms by which omega-3 PUFAs may contribute to improved adult physical performance could be hypothesized.

Conclusion

Omega-3 PUFAs are gaining growing attention for their positive effect on muscle function parameters. The integration of physical function measures in future studies would be of great interest to explore whether omega-3 PUFAs could contribute to improved muscle function, starting from early life and extending throughout the lifespan. However, larger and high-quality RCTs are needed to fully elucidate the beneficial effects of omega-3 PUFAs supplementation on muscle mass and function.

Association between gait speed deterioration and EEG abnormalities

Physical and cognitive decline at an older age is preceded by changes that accumulate over time until they become clinically evident difficulties. These changes, frequently overlooked by patients and health professionals, may respond better than fully established conditions to strategies designed to prevent disabilities and dependence in later life. The objective of this study was twofold; to provide further support for the need to screen for early functional changes in older adults and to look for an early association between decline in mobility and cognition. A cross-sectional cohort study was conducted on 95 active functionally independent community-dwelling older adults in Havana, Cuba. We measured their gait speed at the usual pace and the cognitive status using the MMSE. A value of 0.8 m/s was used as the cut-off point to decide whether they presented a decline in gait speed. A quantitative analysis of their EEG at rest was also performed to look for an associated subclinical decline in brain function. Results show that 70% of the sample had a gait speed deterioration (i.e., lower than 0.8 m/s), of which 80% also had an abnormal EEG frequency composition for their age. While there was no statistically significant difference in the MMSE score between participants with a gait speed above and below the selected cut-off, individuals with MMSE scores below 25 also had a gait speed<0.8 m/s and an abnormal EEG frequency composition. Our results provide further evidence of early decline in older adults-even if still independent and active-and point to the need for clinical pathways that incorporate screening and early intervention targeted at early deterioration to prolong the years of functional life in older age.

Defining and Measuring Preclinical Mobility Limitation: An Expert Consensus Exercise Informed by a Scoping Review

BACKGROUND

Early change in function in older adults has been termed preclinical disability (PCD). PCD has been understudied compared to other stages of disability because it is unlikely to receive comparative priority in clinical settings. It has major implications for prevention and population health as it may be the optimal time to intervene to prevent further decline. A standardized approach to research in PCD, including a common definition and measurement approaches, is needed to advance this work.

METHODS

The process to establish how PCD should be defined and measured was undertaken in 2 stages: (1) a scoping review of the literature, which was used to inform (2) a web-enabled consensus meeting with content experts.

RESULTS

The scoping review and the consensus meeting support the use of the term preclinical mobility limitation (PCML) and that it should be measured using both patient-reported and performance-based measures. It was agreed that the definition of PCML should include modification of frequency and/or method of task completion, without overt disability, and that requisite mobility tasks include walking (distance and speed), stairs, and transfers.

CONCLUSIONS

Currently, there are few standardized assessments that can identify PCML. PCML is the term that most clearly describes the stage where people experience a change in routine mobility tasks, without a perception of disability. Further evaluation into the reliability, validity, and responsiveness of outcome measures is needed to advance research on PCML.

Prevalence and Predictors of Ambulatory Care Physicians' Documentation of Mobility Limitations in Older Adults

OBJECTIVE

To determine how often physicians document mobility limitations in visits with older adults, and which patient, physician, and practice characteristics associate with documented mobility limitations.

DESIGN

We completed a cross-sectional analysis of National Ambulatory Medical Care Surveys, years 2012-2016. Multivariate analyses were conducted to identify patient, physician, and practice-level factors associated with mobility limitation documentation.

SETTING

Ambulatory care visits.

PARTICIPANTS

We analyzed visits with adults 65 years and older. Final sample size represented 1.3 billion weighted visits.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE

We defined the presence/absence of a mobility limitation by whether any International Classification of Diseases (ICD)-9 or ICD-10 code related to mobility limitations, injury codes, or the patient's "reasons for visit" were documented in the visits.

RESULTS

The overall prevalence of mobility limitation documentation was 2.4%. The most common codes were falls-related. Patient-level factors more likely to be associated with mobility limitation documentation were visits by individuals over 85 years of age, relative to 65-69 years, (odds ratio 2.32, 95% confidence interval 1.76-3.07]; with a comorbid diagnosis of arthritis (odds ratio 1.35, 1.18-2.01); and with a comorbid diagnosis of cerebrovascular disease (odds ratio 1.60, 1.13-2.26). Patient-level factors less likely to be associated with mobility limitation documentation were visits by men (odds ratio 0.80, 0.64-0.99); individuals with a cancer diagnosis (odds ratio 0.76, 0.58-0.99); and by individuals seeking care for a chronic problem (relative to a new problem [odds ratio 0.36, 0.29-0.44]). Physician-level factors associated with an increased likelihood of mobility limitation documentation were visits to neurologists (odds ratios 4.48, 2.41-8.32) and orthopedists (odds ratio 2.67, 1.49-4.79) compared with primary care physicians. At the practice-level, mobility documentation varied based on the percentage of practice revenue from Medicare.

CONCLUSIONS

Mobility limitations are under-documented and may be primarily captured when changes in function are overt.

Influenza infection is not associated with phenotypical frailty in older patients, a prospective cohort study

Background and Aims

Influenza is a challenging infectious illness for older adults. It is not completely clear whether influenza is associated with frailty or functional decline. We sought to determine the association between incident influenza infection and frailty and prefrailty in community patients over 50 years of age. We also investigated the association between influenza vaccination and frailty and prefrailty as a secondary aim.

Methods

This was a prospective community cohort study from October 2019 to November 2020 in participants over 50 years. The primary outcome was the development of frailty as defined by three of five frailty criteria (slow gait speed, low grip strength, 5% weight loss, low energy, and low physical functioning). The primary predictor was a positive polymerase chain reaction (PCR) for influenza infection. Influenza vaccination was based on electronic health record reviewing 1 year before enrollment. We reported the relationship between influenza and frailty by calculating odds ratios (OR) with 95% confidence intervals (CI) after adjustment for age, sex, socioeconomic status, Charlson Comorbidity Index (CCI), influenza vaccine, and previous self-rated frailty from multinomial logistic regression model comparing frail and prefrail to nonfrail subjects.

Results

In 1135 participants, the median age was 67 years (interquartile range  60-74), with 41% men. Eighty-one participants had PCR-confirmed influenza (7.1%). Frailty was not associated with influenza, with an OR of 0.50 (95% CI 0.17-1.43) for frail participants compared to nonfrail participants. Influenza vaccination is associated with frailty, with an OR of 1.69 (95% CI 1.09-2.63) for frail compared to nonfrail. Frailty was associated with a higher CCI with an OR of 1.52 (95% CI 1.31-1.76).

Conclusion

We did not find a relationship between influenza infection and frailty. We found higher vaccination rates in participants with frailty compared to nonfrail participants While influenza was not associated with frailty, future work may involve longer follow-up.

Agreement between standard and self-reported assessments of physical frailty syndrome and its components in a registry of community-dwelling older adults

BACKGROUND

The ability to identify frail older adults using a self-reported version of the physical frailty phenotype (PFP) that has been validated with the standard PFP could facilitate physical frailty detection in clinical settings.

METHODS

We collected data from volunteers (N = 182), ages 65 years and older, in an aging research registry in Baltimore, Maryland. Measurements included: standard PFP (walking speed, grip strength, weight loss, activity, exhaustion); and self-reported questions about walking and handgrip strength. We compared objectively-measured gait speed and grip strength to self-reported questions using Cohen's Kappa and diagnostic accuracy tests. We used these measures to compare the standard PFP with self-reported versions of the PFP, focusing on a dichotomized identification of frail versus pre- or non-frail participants.

RESULTS

Self-reported slowness had fair-to-moderate agreement (Kappa(k) = 0.34-0.56) with measured slowness; self-reported and objective weakness had slight-to-borderline-fair agreement (k = 0.10-0.21). Combining three self-reported slowness questions had highest sensitivity (81%) and negative predictive value (NPV; 91%). For weakness, three questions combined had highest sensitivity (72%), while all combinations had comparable NPV. Follow-up questions on level of difficulty led to minimal changes in agreement and decreased sensitivity. Substituting subjective for objective measures in our PFP model dichotomized by frail versus non/pre-frail, we found substantial (k = 0.76-0.78) agreement between standard and self-reported PFPs. We found highest sensitivity (86.4%) and NPV (98.7%) when comparing the dichotomized standard PFP to a self-reported version combining all slowness and weakness questions. Substitutions in a three-level model (frail, vs pre-frail, vs. non-frail) resulted in fair-to-moderate agreement (k = 0.33-0.50) with the standard PFP.

CONCLUSIONS

Our results show potential utility as well as challenges of using certain self-reported questions in a modified frailty phenotype. A self-reported PFP with high agreement to the standard phenotype could be a valuable frailty screening assessment in clinical settings.

Association of Handgrip Strength in Various Disabilities in Korean Adults over 50 Years Old: A Nationwide Cross-Sectional Study

Several studies have shown an association between low hand grip strength (HGS) and functional limitations. This study aims to elucidate the association between HGS and functional limitations. We used the nationwide health examination data and included 13,517 Korean adults that were aged ≥ 50 years. We measured HGS using digital dynamometer and the maximum value of the dominant hand was divided into quartiles for the analysis. Functional limitations were assessed by using self-administered questionnaires. We categorized the 24 reported causes of functional limitations into musculoskeletal, cardiometabolic, neuropsychiatric, cancers, and others. In multiple regression analysis, the functional limitations tended to increase as HGS was lowered in both sexes. When analyzing according to the reasons of functional limitations, the ORs for functional limitations due to cardiometabolic problem tended to increase as the HGS decreased in men (p for trend = 0.039). Similar trends were observed in neuropsychiatric problem in women (p for trend = 0.002) and other problems in both men and women (p for trend = 0.014 in men, p for trend = 0.004 in women). No significant trends were observed for musculoskeletal problems and cancer in both men and women. The functional limitations were inversely associated with HGS, which were inconsistent according to different etiologies of functional limitations.

Aging with Incarceration Histories: An Intersectional Examination of Incarceration and Health Outcomes among Older Adults

OBJECTIVES

Experiences with incarceration are linked to poor mental and physical health across the life course. The purpose of this research is to examine whether incarceration histories are associated with worse physical and mental health among older adults. We apply an intersectionality framework and consider how the intersection of sexism and racism leads to unequal health outcomes following incarceration among women and people of color.

METHODS

We employ two measures of health (i.e., number of depressive symptoms and physical limitations) to broadly capture mental and physical health. Using data from Waves 11 and 12 of the Health and Retirement Study (HRS), we estimated a series of general linear models (GLM) to analyze differences in health by incarceration history, gender/sex, and race/ethnicity.

RESULTS

Findings suggest that experiences with incarceration are associated with a greater number of physical limitations and more depressive symptoms among older men and women, net of sociodemographic characteristics, early-life conditions, and lifetime stressful events. Formerly incarcerated women, particularly women of color, had more physical limitations and depressive symptoms, relative to other groups.

DISCUSSION

These findings suggest that incarceration histories have far-reaching health implications. Older women of color with incarceration histories experience markedly high levels of physical limitations and depressive symptoms in later life.

Ethical Dilemmas with Regard to Elderly Patients with Hip Fracture: The Problem of Nonagenarians and Centenarians

Hip fracture is the most feared complication of osteoporosis, producing up to 30% mortality at the first year. With the aging of society, it is increasingly common to deal with ethical dilemmas that involve decision making in the elderly patient with a hip fracture. The objectives of the present work are to describe the main bioethical dilemmas in this group of patients and their relationship with surgical delay. We conducted a retrospective descriptive study that studied an elderly population admitted to a University Hospital with a diagnosis of hip fracture. In total, 415 patients were analyzed. The majority received surgical treatment, a correct application of the principles of justice, non-maleficence and beneficence is verified, but a possible violation of the principle of autonomy is confirmed. Based on the results of this study, the elderly population may somehow lose their principle of autonomy when they enter a hospital due to a hip fracture. On the other hand, the so-called ageism due to ignorance can influence the surgical delay and therefore the mortality of these patients.

Church Attendance and Mobility Limitation Among Black and White Men With Prostate Cancer

Prostate cancer is a significant impediment that can reduce physical functional status. Mobility is fundamental for quality of life and church attendance to be associated with improved physical functioning. Few studies have examined how religious participation have implications for mobility limitation among men in general and among prostate cancer survivors in particular. The purpose of this study was to assess the association between church attendance and mobility limitation among Black and White prostate cancer patients and survivors. Data for this investigation were drawn from the Diagnosis and Decisions in Prostate Cancer Treatment Outcomes Study that consisted of 804 Black and White men with complete information on the primary outcome and predictor variables. Mobility limitation was the primary outcome variable, and church attendance was the main independent variable. The analytic sample was almost equally divided between Black (N = 382) and White men (N = 422). The proportion of Black men reporting mobility limitation (30.09%) more than doubled the corresponding percentage for White men (14.7%). Black men had a higher proportion of individuals who reported weekly church attendance (49.2% vs. 45.0%). Fully adjusted modified Poisson regression models produced results indicating that respondents attending church weekly had a lower mobility limitation prevalence (PR = 0.56, 95% CI [0.39, 0.81]) than those never attending church. Results from this study contribute to the body of evidence asserting the health benefits of church attendance. These findings suggest that health providers should consider how religion and spirituality can present opportunities for improved outcomes in prostate cancer patients and survivors.

Adolescent measures of family socioeconomic status: Reliability, validity, and effects on substance use behaviors in adolescence and young adulthood

Socioeconomic status (SES) is a robust predictor of health disparities in adolescence and early adulthood, yet obtaining accurate and reliable measurements of family SES from younger participants remains a challenge. We evaluated the reliability and validity of a subjective SES measure, i.e., perceived family financial security (PFS), which assesses adolescents' perceptions of whether their family has enough money to meet their needs. We also examined the predictive associations of PFS and parental education (adolescent reports) with alcohol, marijuana, and tobacco use during adolescence and young adulthood. Longitudinal data were obtained from 593 parent-child dyads in the Pacific Northwest region of the United States, who were assessed eight times between 2005 and 2014. Present analyses included data from four annual assessments conducted when the participating children were adolescents (age range = 10.25-16.33 years) and a final follow-up in young adulthood (age range = 20-23.42 years). PFS had good test-retest reliability and convergent validity with other parent and adolescent reported SES measures. Adolescent-reported PFS significantly predicted tobacco use frequency in young adulthood, whereas adolescent-reported parental education predicted alcohol use frequency. PFS was not a significant predictor of alcohol or marijuana use. Findings suggest that PFS can be a psychometrically sound measure to assess a unique dimension of SES in adolescent samples, with differential predictive associations among substance use outcomes in young adulthood compared to more traditional measures like parental education. Future research should evaluate the psychometric properties and utility of PFS as a complementary SES measure.

Stand Up Now: A Sedentary Behavior Intervention in Older Adults of Moderate to Low Physical Function

OBJECTIVES

To examine the efficacy of an the intervention Stand Up Now (SUN) to reduce sedentary behavior (SB) and improve physical function and mobility.

METHODS

SUN included two groups: (a) focused on reducing total SB (SUNSL) and (b) focused on increasing sit-to-stand (STS) transitions (SUNSTS). The participants (N = 71; Mage = 87 ± 7 years) had 12 weekly health coaching sessions. SB, physical function, and mobility were measured at the baseline, 6, and 12 weeks via the activPAL, Short Physical Performance Battery, and the 8-foot up and go, respectively. Linear mixed models examined the outcome variables over time.

RESULTS

Both groups decreased sedentary time (1.3 ± 0.3 hr, p < .001), increased standing time (0.5 ± 0.2 hr, p < .02), and improved physical function (1.5 ± 0.4 points, p < .001) from the baseline to 6 weeks, and they maintained it at 12 weeks. SUNSTS increased STS transitions (5.4 ± 4.1, p < .001), while SUNSL had no changes (0.5 ± 3.1, p > .9). There were no changes in mobility for either group (0.5 ± 1.5 s, p > .05).

DISCUSSION

SUN demonstrates the efficacy to improve SB and physical function in older adults.

Formative Evaluation of Consumer-Grade Activity Monitors Worn by Older Adults: Test-Retest Reliability and Criterion Validity of Step Counts

Background

To assess whether commercial-grade activity monitors are appropriate for measuring step counts in older adults, it is essential to evaluate their measurement properties in this population.

Objective

This study aimed to evaluate test-retest reliability and criterion validity of step counting in older adults with self-reported intact and limited mobility from 6 commercial-grade activity monitors: Fitbit Charge, Fitbit One, Garmin vívofit 2, Jawbone UP2, Misfit Shine, and New-Lifestyles NL-1000.

Methods

For test-retest reliability, participants completed two 100-step overground walks at a usual pace while wearing all monitors. We tested the effects of the activity monitor and mobility status on the absolute difference in step count error (%) and computed the standard error of measurement (SEM) between repeat trials. To assess criterion validity, participants completed two 400-meter overground walks at a usual pace while wearing all monitors. The first walk was continuous; the second walk incorporated interruptions to mimic the conditions of daily walking. Criterion step counts were from the researcher tally count. We estimated the effects of the activity monitor, mobility status, and walk interruptions on step count error (%). We also generated Bland-Altman plots and conducted equivalence tests.

Results

A total of 36 individuals participated (n=20 intact mobility and n=16 limited mobility; 19/36, 53% female) with a mean age of 71.4 (SD 4.7) years and BMI of 29.4 (SD 5.9) kg/m². Considering test-retest reliability, there was an effect of the activity monitor (P<.001). The Fitbit One (1.0%, 95% CI 0.6% to 1.3%), the New-Lifestyles NL-1000 (2.6%, 95% CI 1.3% to 3.9%), and the Garmin vívofit 2 (6.0%, 95 CI 3.2% to 8.8%) had the smallest mean absolute differences in step count errors. The SEM values ranged from 1.0% (Fitbit One) to 23.5% (Jawbone UP2). Regarding criterion validity, all monitors undercounted the steps. Step count error was affected by the activity monitor (P<.001) and walk interruptions (P=.02). Three monitors had small mean step count errors: Misfit Shine (−1.3%, 95% CI −19.5% to 16.8%), Fitbit One (−2.1%, 95% CI −6.1% to 2.0%), and New-Lifestyles NL-1000 (−4.3%, 95 CI −18.9% to 10.3%). Mean step count error was larger during interrupted walking than continuous walking (−5.5% vs −3.6%; P=.02). Bland-Altman plots illustrated nonsystematic bias and small limits of agreement for Fitbit One and Jawbone UP2. Mean step count error lay within an equivalence bound of ±5% for Fitbit One (P<.001) and Misfit Shine (P=.001).

Conclusions

Test-retest reliability and criterion validity of step counting varied across 6 consumer-grade activity monitors worn by older adults with self-reported intact and limited mobility. Walk interruptions increased the step count error for all monitors, whereas mobility status did not affect the step count error. The hip-worn Fitbit One was the only monitor with high test-retest reliability and criterion validity.

The relationship between interleukin-6 levels and physical performance in mobility-limited older adults with chronic low-grade inflammation: The ENRGISE Pilot study

Previous studies have found an inverse relation between serum concentrations of interleukin (IL)-6 and physical performance in seniors, however this was limited to higher functioning older adults with low to moderate levels of inflammation. We explored the consistency of this association in a cohort of mobility limited older adults with chronic low-grade inflammation. This study included 289 participants (≥ 70 years old) with IL-6 level between 2.5 and 30 pg/mL and a walking speed < 1.0 m/sec from the ENRGISE Pilot study. Physical performance was assessed using the short physical performance battery (SPPB), usual gait speed over 400 m, grip strength, and knee extensor and flexor strength measured by isokinetic dynamometry at 60 and 180°/sec. There was a significant inverse correlation between log IL-6 and knee extensor strength at 60°/sec (r= -0.20, p = 0.002), at 180°/sec (r = -0.14, p = 0.037), and knee flexor strength at 60°/sec (r = -0.15, p = 0.021). After adjustment for potential confounders, the values of knee extensor strength at 60°/sec showed a trend toward a progressive reduction across IL-6 tertiles as IL-6 levels increased (p = 0.024). No significant association was found between IL-6 and other objectively measured physical performance. The findings were generally of smaller magnitude and less consistent than previously reported, which suggests that the associations are attenuated in those with both elevated inflammation and mobility limitations. These results have implications for planning and interpreting future intervention studies in older adults with low-grade inflammation and mobility limitations.

Race differences in mobility status among prostate cancer survivors: The role of socioeconomic status

The objective of this paper was to determine whether there were any race differences in mobility limitation among PCa survivors, and understand the impact of socioeconomic status (SES) on this relationship. Data consisted of 661 PCa survivors (296 Black and 365 White) from the Diagnosis and Decisions in Prostate Cancer Treatment Outcomes (DAD) Study. Mobility limitation was defined as PCa survivors who reported difficulty walking a quarter mile or up 1 flight of stairs. Race was based on the PCa survivors self-identification of either White or Black. SES consisted of education level (i.e., less than high school, high school/GED, some college/associate, bachelors, masters/PhD) and annual household income (i.e., less than $50,000; $50,000-$100,000; greater than $100,000). Adjusting for age, marital status, health insurance, Gleason Score, treatment received, and time to treatment, Black PCa survivors had a higher prevalence of mobility limitation (PR=1.58, 95% CI: 1.17-2.15) relative to White PCa survivors. When adding education and income to the adjusted model, Black PCa survivors had a similar prevalence of mobility limitation (PR=1.12, 95% CI: 0.80-1.56) as White PCa survivors. The unequal distribution of SES resources between Black and White PCa survivors accounted for the observed race differences in mobility limitation. This work emphasizes the importance of SES in understanding race differences in mobility among PCa survivors.

Relationship Between Chronic Conditions and Disability in African American Men and Women

BACKGROUND

Race differences in chronic conditions and disability are well established; however, little is known about the association between specific chronic conditions and disability in African Americans. This is important because African Americans have higher rates and earlier onset of both chronic conditions and disability than white Americans.

METHODS

We examined the relationship between chronic conditions and disability in 602 African Americans aged 50 years and older in the Baltimore Study of Black Aging. Disability was measured using self-report of difficulty in activities of daily living (ADL). Medical conditions included diagnosed self-reports of asthma, depressive symptoms, arthritis, cancer, diabetes, cardiovascular disease (CVD), stroke, and hypertension.

RESULTS

After adjusting for age, high school graduation, income, and marital status, African Americans who reported arthritis (women: odds ratio (OR)=4.87; 95% confidence interval(CI): 2.92-8.12; men: OR=2.93; 95% CI: 1.36-6.30) had higher odds of disability compared to those who did not report having arthritis. Women who reported major depressive symptoms (OR=2.59; 95% CI: 1.43-4.69) or diabetes (OR=1.83; 95% CI: 1.14-2.95) had higher odds of disability than women who did not report having these conditions. Men who reported having CVD (OR=2.77; 95% CI: 1.03-7.41) had higher odds of disability than men who did not report having CVD.

CONCLUSIONS

These findings demonstrate the importance of chronic conditions in understanding disability in African Americans and how it varies by gender. Also, these findings underscore the importance of developing health promoting strategies focused on chronic disease prevention and management to delay or postpone disability in African Americans.

PUBLICATION INDICES

Pubmed, Pubmed Central, Web of Science database.

Randomized Controlled Trial of Exercise to Improve Walking Energetics in Older Adults

Background and Objectives

Mobility limitation is common and has been linked to high energetic requirements of daily activities, including walking. The study objective was to determine whether two separate forms of exercise could reduce the energy cost of walking and secondary outcomes related to activity and participation domains among older adults with mobility limitation.

Research Design and Methods

Community-dwelling older adults with self-reported mobility limitation (n = 72) were randomized to 12 weeks of twice-weekly, group-based, instructor-led timing and coordination, aerobic walking, or stretching and relaxation (active control) programs. The primary outcome was the energy cost of walking (mL O₂/kg/m), assessed by a 5-minute treadmill walking test (0.8 m/s). Secondary outcomes were fatigability, physical activity, endurance, physical function, and life-space. Baseline-adjusted ANCOVAs were used to determine mean differences between exercise and control groups at 12 and 24 weeks.

Results

Exercise session attendance was high: 86% for timing and coordination, 81% for aerobic walking, and 90% for stretching and relaxation. At 12 weeks, timing and coordination reduced the mean energy cost of walking by 15% versus stretching and relaxation (p = .008). Among those with high baseline cost, timing and coordination reduced mean energy cost by 20% versus stretching and relaxation (p = .055). Reductions were sustained at 24 weeks. Aerobic walking had no effect on the energy cost of walking at 12 or 24 weeks. At 12 weeks, there was a trend toward faster gait speed (by 0.1 m/s) in timing and coordination versus stretching and relaxation (p = .074). Fatigability, physical activity, endurance, physical function, and life-space did not change with timing and coordination or aerobic walking versus stretching and relaxation at 12 or 24 weeks.

Discussion and Implications

Twelve weeks of timing and coordination, but not aerobic walking, reduced the energy cost of walking among older adults with mobility limitation, particularly among those with high baseline energy cost; reductions in energy cost were sustained following training cessation. Timing and coordination also led to a trend toward faster gait speed.

Could Activity Modifications Indicate Physical Decline Among Adults With Symptomatic Knee Osteoarthritis?

OBJECTIVES

Mobility activity modifications indicate early functional losses that act as precursors to future declines among community-dwelling older adults. However, there is scarce evidence on whether activity modifications indicate poorer physical health among adults with symptomatic osteoarthritis, a major cause of disability. Our purpose was to investigate whether patient-reported mobility activity modifications indicated poorer physical health among adults with symptomatic knee osteoarthritis.

DESIGN

Secondary cross-sectional analysis of randomized trial data was performed. Preclinical Disability Questionnaire was used to group participants into the following three categories: difficulty, modified, and no difficulty walking/stair climbing. Kruskal Wallis and χ tests were used to compare clinical factors across groups.

RESULTS

Among 121 participants (median age = 60 yrs; 73% female; 60% white), less than 10% had modified walking/stair climbing. Compared with those with no walking difficulty, participants with modified walking had significantly less balance (P = 0.01) and global health (P = 0.01) as well as greater knee pain (P = 0.05) and physical disability (P = 0.04). Those with modified stair climbing had significantly smaller walking distances (P = 0.03) compared with those with no difficulty stair climbing.

CONCLUSIONS

Activity modifications may signal early impairments in physical health among people with symptomatic knee osteoarthritis. If confirmed, patient-reported activity modifications may enhance symptom evaluation in osteoarthritis and enable a better understanding of the disablement process.

Relationship between Physical Function and Sleep Quality in African Americans

STUDY OBJECTIVES

There is a growing body of research examining the relationship between sleep and functional outcomes. However, little is known about sleep and physical functioning in older African Americans.

METHODS

Data for this project included 450 community-dwelling older African Americans (71.4 ± 9.2 years of age) who participated in the Baltimore Study of Black Aging. Overall sleep pattern and quality was measured by the Pittsburgh Sleep Quality Index (PSQI). Physical functioning was measured by the number of activities of daily living that each participant reported difficulty (ADL; e.g. eating, dressing, and bathing). Negative binomial regression models were conducted to estimate the association between sleep quality and physical functioning.

RESULTS

Seventy-two percent of the participants reported poor sleep quality. African Americans who reported poor sleep quality had a greater likelihood of an increase in the number of difficulties in ADLs that they reported even after accounting for demographic characteristics and health conditions. The relationship between sleep quality and physical functioning did not vary by gender.

CONCLUSIONS

Sleep may be an important factor to consider when seeking to improve physical functioning among community-dwelling older African Americans.

A New Paradigm of Technology-Enabled ‘Vital Signs’ for Early Detection of Health Change for Older Adults

Environmentally embedded (nonwearable) sensor technology is in continuous use in elder housing to monitor a new set of ‘vital signs' that continuously measure the functional status of older adults, detect potential changes in health or functional status, and alert healthcare providers for early recognition and treatment of those changes. Older adult participants' respiration, pulse, and restlessness are monitored as they sleep. Gait speed, stride length, and stride time are calculated daily, and automatically assess for increasing fall risk. Activity levels are summarized and graphically displayed for easy interpretation. Falls are detected when they occur and alerts are sent immediately to healthcare providers, so time to rescue may be reduced. Automated health alerts are sent to healthcare staff, based on continuously running algorithms applied to the sensor data, days and weeks before typical signs or symptoms are detected by the person, family members, or healthcare providers. Discovering these new functional status ‘vital signs', developing automated methods for interpreting them, and alerting others when changes occur have the potential to transform chronic illness management and facilitate aging in place through the end of life. Key findings of research in progress at the University of Missouri are discussed in this viewpoint article, as well as obstacles to widespread adoption.

INTERSECTING SELF-REPORTED MOBILITY AND GAIT SPEED TO CREATEA MULTI-DIMENSIONAL MEASURE OF AMBULATION: THE "AMBULATION SPEED-ENDURANCE" (ASE) TYPOLOGY

BACKGROUND

Assessing mobility through readily available and affordable protocols may help advance public health by providing early detection and implementing intervention therapies aimed at mitigating the progression from physiological vitality to disability at older ages. Until now, little attention has been given to how self-reported mobility (SRM) and gait speed can be combined in a categorization scheme.

OBJECTIVES

The specific aim of this report is to introduce the Ambulation Speed-Endurance (ASE) Typology to the literature-a classification system that intersects SRM and gait speed to create a multi-dimensional measure of ambulation.

DESIGN

Cross-sectional.

SETTING

Community-dwelling older adults in the United States.

PARTICIPANTS

Evidence is provided from the National Health and Aging Trends Study (NHATS) that community-dwelling older adults (n=5,403) may be found in each of the ASE Typologies. The discussion is complimented by investigating the cross-sectional predictors of a "Discrepancy Score" (measure of gap between speed and endurance) amongst those with gait speeds < 0.99 m/sec (n=4,521).

RESULTS

Multivariable linear regression results indicate level of severity in speed-endurance discrepancy is higher amongst: non-Latino-Blacks (β=0.48); Latinos (β=0.42); older ages; and lower educated. Models also show that severity in speed-endurance discrepancy is lower amongst: females (β=-0.38); those with higher body mass index; with more chronic health conditions; and poorer self-rated health.

CONCLUSION

Research should continue to investigate how to optimize SRM.

Compensatory Strategies: Prevalence of Use and Relationship to Physical Function and Well-Being

We examine prevalence of four compensatory strategies (assistive devices, receiving help, changing frequency, or method of performance) and their immediate and long-term relationship to well-being. A total of 319 older adults (>70 years) with functional difficulties at home provided baseline data; 285 (89%) provided 12-month data. For 17 everyday activities, the most frequently used strategy was changing method of performance ( M = 10.27 activities), followed by changing frequency ( M = 6.17), assistive devices ( M = 5.38), and receiving help ( M = 3.37; p = .001). Using each strategy type was associated with functional difficulties at baseline ( ps < .0001), whereas each strategy type except changing method predicted functional decline 12 months later ( ps < .0001). Changing frequency of performing activities was associated with depressed mood ( p < .0001) and poor mastery ( p < .0001) at both baseline and 12 months ( ps < .02). Findings suggest that strategy type may be differentially associated with functional decline and well-being although reciprocal causality and the role of other factors in these outcomes cannot be determined from this study.

The relationship between sleep and physical function in community-dwelling adults: a pilot study

More than 50% of community-dwelling adults have sleep complaints. Because aging is associated with decline in physical function, coexistent sleep difficulties may exacerbate functional decline. This pilot study explored the relationships between sleep, age, chronic disease burden, and physical function among 50 community-dwelling older adults. Findings revealed significant relationships between total sleep time and preclinical disability (r = -0.33, P ≤ .05) and mobility difficulty (r = -0.36, P ≤ .05). A regression analysis showed that total sleep time was significantly associated with mobility difficulty and preclinical disability, even after controlling for chronic disease burden. These findings suggest that total sleep time may be a catalyst for functional decline.

Diving below the surface of progressive disability: considering compensatory strategies as evidence of sub-clinical disability

OBJECTIVES

To provide a comprehensive review regarding the role of activity and participation compensations within the disablement process, identify directions for future research, and discuss the implications of compensation pertaining to public health initiatives aimed at preventing and reversing disability.

METHOD

This article evaluated how using compensatory strategies to cope with functional deficits reveals important transitions within the disablement process and signifies a unique opportunity to identify early declines in function.

RESULTS

Previous research suggests that (a) adopting compensatory strategies to maintain activity/participation is strongly associated with functional decline and disease severity and significantly predicts the onset of limitations/restrictions; (b) compensation can be reliably quantified; and (c) contextual knowledge about how individuals adapt to functional decline can be used to describe transitions in the disablement process.

DISCUSSION

Characterizing subtle adaptations prior to the onset of activity limitations and participation restrictions will not only aid in understanding the complex disablement process but also help inform social services and future prevention strategies. Overall, this article integrates the concept of compensation into the current model of disability and proposes a framework for identifying and interpreting compensatory behavior.

What do older people understand by mobility-related difficulties?

Despite the centrality of the difficulty concept in the study of disability, there has been little research on its significance from the point of view of people with functional limitations. The main objective of this study was to describe what older people understand when asked about difficulty in undertaking mobility activities. As a secondary objective, we considered whether there are any differences depending on the type of activities, according to the International Classification of Functioning (ICF) mobility domains.

METHODS

Seventeen community-dwelling men and women aged 70 years old or over were interviewed by means of a questionnaire containing 55 items covering the ICF mobility domains. The participants responded to the items while thinking aloud, saying what led them to give a specific answer about their level of difficulty. Inductive content analysis was conducted and categories, subthemes and themes were identified.

RESULTS

Causes of difficulty (pathologies, impairments, symptoms) and accommodations (task modifications and use of aids) were the two themes identified; and their importance (and that of the subthemes included) varied across the types of activity. All the participants said that they had no difficulty in at least one task, despite mentioning changes in the way they performed them.

CONCLUSIONS

Older people's opinions were consistent with theoretical models of disability and with the standard practice of measuring functional limitations by asking about the degree of difficulty; however, the design of these measures needs to be improved in order to detect perceptions of no difficulty in the presence of task modification.

Psychosocial influences in onset and progression of late life disability

OBJECTIVES

Disability in older age has been related to several psychosocial characteristics, including social networks, social engagement, and depression. However, the exact role of these characteristics in the disablement process remains uncertain.

METHOD

Data come from a population-based study of black and white adults aged ≥65 years (N = 5,306), with up to 9 yearly data on the primary outcome measure, activities of daily living (ADL) disability. We use a two-part regression model to simultaneously test the association between each psychosocial characteristic and both onset and progression of ADL disability, while controlling for demographic variables, education, and mode of interview in the first model and health status variables in the second model.

RESULTS

Social networks were negatively associated with onset of ADL disability but not associated with progression. The association became non-significant after adjustment for health status. Social engagement was negatively associated with both onset and progression of disability, even after adjustment for health status. Depression was significantly associated with onset of disability after adjustment for health status but not with progression of disability.

DISCUSSION

The results suggest a differential role for psychosocial characteristics in the disablement process, with generally stronger associations for transitions to onset of ADL disability than progression of ADL disability.

Development and validation of a lung transplant-specific disability questionnaire

BACKGROUND

Lung transplant (LT) aims to extend survival and improve patient-centred outcomes (PCOs) by reducing disability and improving health-related quality of life (HRQL). Few PCO instruments have been validated in LT populations. We aimed to develop and validate a shortened version of the valued life activities (VLA) disability scale specific to LT.

METHODS

We used data from 140 subjects participating in an ongoing cohort study of LT. Subjects completed a survey battery, including VLA items, and physical assessments before LT. To develop a shortened LT-specific VLA (LT-VLA), we iteratively deleted items from a longer 32-item VLA battery, retaining the instrument's conceptual framework, scoring and performance characteristics. We evaluated LT-VLA validity by testing correlations with a HRQL measure (Short Form-12 Physical Function (SF-12 PF) subscale), forced vital capacity % (FVC%) predicted and 6 minute walk distance (6MWD). Responsiveness was evaluated in 84 subjects who completed assessments before and after LT.

RESULTS

The 15-item LT-VLA scoring closely matched the longer VLA (correlations ≥0.96) and had excellent internal consistency (Cronbach's α 0.92). The LT-VLA required only 3 min or less to administer. The LT-VLA, measured as mean difficulty in performing each of the 15 activities queried, correlated with FVC% predicted (r=-0.30), 6MWD (r=-0.38) and SF-12 PF (r=-0.47) (all p<0.01). The LT-VLA mean difficulty was responsive to change from before to after LT (63% improvement; effect size=1.60).

CONCLUSIONS

The LT-VLA is a short, easy to administer, valid and responsive disease-specific PCO instrument that may be useful in clinical and research applications for lung transplantation.

Voluntary leadership roles in religious groups and rates of change in functional status during older adulthood

Linear growth curve modeling was used to compare rates of change in functional status between three groups of older adults: Individuals holding voluntary lay leadership positions in a church, regular church attenders who were not leaders, and those not regularly attending church. Functional status was tracked longitudinally over a 4-year period in a national sample of 1,152 Black and White older adults whose religious backgrounds were either Christian or unaffiliated. Leaders had significantly slower trajectories of increase in both the number of physical impairments and the severity of those impairments. Although regular church attenders who were not leaders had lower mean levels of impairment on both measures, compared with those not regularly attending church, the two groups of non-leaders did not differ from one another in their rates of impairment increase. Leadership roles may contribute to longer maintenance of physical ability in late life, and opportunities for voluntary leadership may help account for some of the health benefits of religious participation.

Increased load computerized dynamic posturography in prefrail and nonfrail community-dwelling older adults

The understanding of prefrail and nonfrail older adults' postural control with and without increased environmental and cognitive stress is imperative to the development of targeted interventions to decrease fall risk within these populations. Thirty-eight individuals participated in this study. Postural control testing included the Sensory Organization Test (SOT) on a NeuroCom EquiTest. Cognitive and environmental load testing was performed during Condition 6 of the SOT. Though there were no group differences on composite equilibrium score (p = .06), the cognitive task (Stroop task) impaired equilibrium scores more than the auditory or visual distracter tasks (p < .05 and p < .01) for both groups. These results suggest that both prefrail and nonfrail older adults' postural control is reduced in demanding environments. Given these findings, the need for multimodal exercise interventions to target both physical and cognitive factors is apparent.

Lower-extremity force decrements identify early mobility decline among community-dwelling older adults

BACKGROUND

Many apparently independent older adults modify daily tasks. Task modifications strongly predict future mobility disability. Clinically intuitive, easily measured "biomarkers" associated with task modifications would offer quantifiable treatment targets for prevention of age-related functional limitations.

OBJECTIVE

The objective of the study was to examine lower-extremity muscle strength deficits and functionally relevant cutoff points associated with daily task modifications in community dwelling older adults living independently.

DESIGN

This was a cross-sectional observational study.

METHODS

Fifty-three participants (mean age=76.4 years, SD=5.2) were tested for task modifications and leg strength. Task modifications were assessed using a previously described tool (summary task modification score). Twenty-six of the participants were classified as task modifiers (TM group), and 27 participants were classified as non-task modifiers (NTM group). A net antigravity leg force in the sagittal plane (NETforce) was calculated by summing the normalized isometric and isokinetic torques from the hip extensors, knee extensors, and ankle plantar flexors.

RESULTS

Compared with the NTM group, the TM group exhibited 30.0% and 33.5% reduction in lower-extremity isometric and isokinetic NETforces, respectively. Isometric and isokinetic NETforce cutoff points for task modifications were ≤ 4.24 and 2.77 N · m/kg body weight, respectively. The isometric and isokinetic models both yielded sensitivity and specificity values of 74.1% and 80.8%, respectively (positive likelihood ratio=3.852, 95% confidence interval=1.699-8.735; negative likelihood ratio=0.321, 95% confidence interval=0.167-0.618). Isometric and isokinetic NETforces were significantly associated with task modifications (odds ratio=2.50 and 2.42, respectively).

LIMITATIONS

The cross-sectional design of this study does not allow for a test of causal relationships. This study used a modest yet adequate sample size that may limit generalization of the results.

CONCLUSIONS

Isometric and isokinetic NETforce cutoff points provide quantifiable biomarkers that discriminate community-dwelling older adults who modify daily tasks from those who do not.

Role of self-efficacy (SE) and anxiety among pre-clinically disabled older adults when using compensatory strategies to complete daily tasks

Classic developmental theory suggests that aging is associated with using compensatory strategies to prolong independence. While compensatory strategies are typically considered positive adaptations, they also signify an early phase in the disablement process - commonly known as pre-clinical disability. To build a better understanding of psychological constructs related to these early signs of disability, we examined the contribution of SE and state anxiety on using compensatory strategies among pre-clinically disabled older adults. Compensatory strategies were observed during performance of daily activities in 257 pre-clinically disabled older adults (67.6 ± 7.04), and SE and state anxiety were evaluated prior to performing each task. In univariate models, lower SE and higher anxiety were associated with more compensation (Spearman correlations: 0.15-0.48, p<0.05). Multivariate logistic regression indicated that low SE [Odds Ratio (OR): 1.70; 95% Confidence Interval (CI): 1.40-2.08) and high anxiety (OR: 1.34; 95% CI: 1.10-1.63) were positively associated with using ≥6 compensatory strategies - a level signifying substantial compensation. When considered jointly with SE, the association with anxiety was reversed - higher anxiety demonstrated a lower likelihood of using compensation (OR: 0.70-0.73; 95% CI: 0.50-0.99). The addition of SE might remove the self-defeating cognitions characterizing anxiety allowing the remaining arousal component to appear beneficial. In conclusion, lower SE and higher anxiety are associated with using compensation to complete daily tasks among pre-clinically disabled older adults. Such psychological constructs may contribute to the use of compensatory strategies and represent future intervention targets to help reduce early signs of disability.

Obesity and use of compensatory strategies to perform common daily activities in pre-clinically disabled older adults

OBJECTIVES

To examine the association between the use of compensatory strategies to successfully complete common daily activities-an indicator of pre-clinical disability-and body mass in pre-clinically disabled older adults.

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Two hundred and fifty-nine pre-clinically disabled older adults defined as having changed the frequency or manner of performing daily tasks without reporting any difficulty.

MEASUREMENTS

The use of compensatory strategies were objectively evaluated using the Modification (MOD) scale-a reliable and valid scale for assessing the manner in which common daily activities were completed. Height and weight were measured to classify participants into the following body mass index (BMI) categories: (1) normal: 18.5-24.9 kg/m(2), (2) overweight: 25.0-29.9 kg/m(2), (3) obese class I: 30.0-34.9 kg/m(2), and (4) obese class II: 35.0-39.9 kg/m(2).

RESULTS

Compared to other BMI categories, individuals with class II obesity demonstrated a significantly higher probability of using ≥1 compensatory strategies when rising from a chair (30 cm height), kneel to stand, stair ascent, stair descent, and supine to stand tasks. When summarized over all tasks, individuals with class II obesity were 18 times more likely to use extensive compensatory strategies (≥6 on MOD scale) compared to normal weight older adults. Similar trends at a lesser magnitude were found in obese and overweight compared to normal weight older adults.

CONCLUSION

Obesity is associated with extensive use of compensatory strategies when performing common daily tasks prior to the onset of perceived difficulty, thus placing them at higher risk of disability compared to their peers with lower body mass.

Development of physical disability in older adults

Demographers expect the number of older persons to double to 86.7 million - or to 20.6% of the US population - by the year 2050. As has occurred over the past decade, the health care costs associated with older age are expected to steadily increase approximately 2% per year causing both a public health and personal burden. A key component to reducing health care costs and maintaining well-being in older persons is preserving physical function throughout the lifespan. The challenge to this objective is to combat the origin of the loss of physical function through treatment of chronic disease conditions. Another approach is to enhance physical function despite the occurrence of comorbid conditions through enhancement of the neuromuscular system. The neuromuscular system provides the necessary components for all locomotion, and is thus a logical choice for preventative therapies to target. This article will give a general overview of the models and risk factors that explain the development of physical disability.

Incident preclinical mobility disability (PCMD) increases future risk of new difficulty walking and reduction in walking activity

PURPOSE

This study examines whether and how report of a change in walking behavior, incident PCMD, predicts subsequent reduction in walking activity.

MATERIALS AND METHODS

Data are from a prospective study of 436 community-dwelling women age 70-79 years. Outcome measures include subjective and objective measures of walking ability at 3 years.

PRINCIPAL RESULTS

Incident PCMD is associated with the loss of walking abilities at 3-years, regardless of baseline physical impairment. Compared to women without, women with incident PCMD at 1.5 years after baseline were 2.7 (95%CI 1.4-7.2) times more likely to report that they no longer walk outdoors at least 8 blocks and 4.9 (1.9-13.1) times more likely to report new difficulty walking. Incident PCMD was also associated with declines in objective outcomes. Incident PCMD is an independent marker of subsequent decreased walking activity.

MAJOR CONCLUSIONS

Incident PCMD appears to be a target for programs to prevent declines in walking activity in older adults.

Correlates of mobility limitation in African Americans

BACKGROUND

This study identified demographic and health-related characteristics that were related to mobility limitation in a sample of community-dwelling African Americans.

METHODS

The sample consisted of 602 community-dwelling African-American men and women ages 48-92 years at study inception. Participants who reported being limited "a lot" or "a little" in climbing one flight of stairs or walking several blocks were considered to have mobility limitation. Logistic regression was conducted to estimate the independent effect of each demographic and health-related characteristic on odds of mobility limitation.

RESULTS

African Americans who reported two or more medical conditions had higher odds of mobility limitation (women: odds ratio = 3.52; 95% confidence interval: 1.89-6.53 and men: odds ratio = 2.53; 95% confidence interval: 1.10-5.85) than those who reported one or fewer medical conditions. African Americans with major depressive symptoms had higher odds of mobility limitation (women: odds ratio = 2.98; 95% confidence interval: 1.55-5.71 and men: odds ratio = 3.19; 95% confidence interval: 1.33-7.65) than those without major depressive symptoms.

CONCLUSIONS

These results highlight the importance of creating interventions particularly focused on chronic disease prevention and management for African American men and women during midlife to attempt to delay the onset or impede the progression of mobility problems that will likely become exacerbated in late life and severely affect the quality of life.

Does diet influence physical performance in community-dwelling older people? Findings from the Hertfordshire Cohort Study

BACKGROUND

recent studies suggest that diet may affect the physical performance of older adults, but the impact of variations in the UK diet on physical performance has not been assessed.

OBJECTIVE

to examine relationships between diet and physical performance in community-dwelling older men and women.

SETTING AND PARTICIPANTS

a total of 628 men and women aged 63-73 years who were taking part in the Hertfordshire Cohort Study.

METHODS

diet was assessed using an administered food frequency questionnaire; physical performance was assessed by the time taken to complete a 3-m walk, chair-rise test and one-legged balance test.

RESULTS

in women, higher intakes of the antioxidant nutrients, β-carotene and selenium, were associated with shorter 3-m walk times; higher β-carotene and vitamin C intakes were associated with shorter chair-rise times (all P < 0.05). Higher vitamin D intakes and percentage energy from protein were also associated with faster 3-m walk times (both P < 0.05), but they were not related to chair-rise time. There were no associations between any measure of dietary intake and balance in the women studied. After adjustment for the effects of confounding influences, we found no associations between diet and physical performance among men.

CONCLUSIONS

these data indicate that variations in the diets of community-dwelling older women may be linked to differences in physical performance, but further work is needed to determine the role of variations in diet on physical performance and its decline with age among older adults in the UK.

Coping with preclinical disability: older women's experiences of everyday activities

PURPOSE

The purpose of this paper is to describe coping practices used by older women during preclinical disability.

DESIGN

This paper was derived from qualitative data gathered during a larger multimethod longitudinal study. Twelve women (60 to 80 years of age) participated in baseline functional performance measures and then repeated in-depth interviews and participant observations over 18 months.

METHODS

A hermeneutic approach was used to interpret the in-depth interviews, participant observations, and field notes using three interrelated processes of thematic, exemplar, and identification of paradigm cases to identify coping practices.

FINDINGS

Women coped with functional decline, such as difficulty getting up from the floor, in many different ways. Coping practices were grouped into five themes: resist, adapt, substitute, endure, and eliminate.

CLINICAL RELEVANCE

These findings suggest that nurses need to realize outward appearances may mask the level of effort required for older women to complete daily activities.

Sensor systems for monitoring functional status in assisted living facility residents

This article provides results of an expert review of data displays for a sensor system used to monitor functional abilities in older adults. The research took place at TigerPlace, an assisted living facility where the sensor system is currently being evaluated. A checklist of 16 heuristic criteria was used to evaluate the sensor data displays, with consideration to the users of the system: residents, their families, and health care providers. Results of this expert review indicate that flexibility and efficiency of use, help and documentation, navigation, and skills were not well developed in the sensor data displays. Conversely, sensor data displays were rated highly for their aesthetic value and the ample visual contrast on the main display components. Through the use of a sensor system, new ways of detecting functional decline in elderly residents of assisted living facilities can be accomplished.

Gait variability detects women in early postmenopause with low bone mineral density

BACKGROUND

Women in early postmenopause and with low bone mineral density (BMD) may exhibit early markers for physical frailty as a result of sarcopenia and osteopenia.

OBJECTIVE

The purpose of this study was to determine whether women in early postmenopause and with low BMD exhibit decreased physical performance and differences in gait variability and fall and fracture rates.

DESIGN

This study was an observational cohort design with participants assigned to groups on the basis of BMD status.

METHODS

Fifty-four women, 31 with low BMD and 23 with normal BMD, participated. This study was conducted in a university research facility. Physical performance was measured by assessment of dynamic balance (timed backward tandem walk test), strength (handheld dynamometry of isometric quadriceps muscle force production), and free gait speed. Gait variability was assessed on the basis of the coefficient of variation for temporal-spatial gait characteristics. Falls and fractures were assessed for the year after initial testing.

RESULTS

Significant between-group differences were found for step time and stance time variability.

LIMITATIONS

The limitations of this study included group assignment on the basis of the results of the most recent bone density scan within the preceding 2 years.

CONCLUSIONS

Women in early postmenopause and with low BMD exhibited increased gait variability in step time and stance time but did not exhibit differences in balance, strength, or gait speed. Gait variability may be more sensitive for detecting differences in women in early postmenopause and with or without low BMD than more typical measures of physical performance.

Transitions among disability levels or death in African American and white older women

BACKGROUND

This study examined the racial differences in probabilities of transitioning across three disability levels of walking (1/2) mile in a community-dwelling population of older women.

METHODS

The sample comprised 436 community-dwelling older women who were among the two-third least disabled women in Baltimore, Maryland. The levels of disability status of walking (1/2) mile included high functioning defined as reporting no difficulty, preclinical disability defined as reports of task modification but no reported difficulty, and disability defined as reported difficulty. First-order Markov transition models were specified to determine whether race influences the types of individual-level transitions between difficulty levels of walking (1/2) mile.

RESULTS

Among high-functioning women, African Americans were more likely to be disabled at the next round than their White counterparts. African American women who began with preclinical disability were more likely to die before the next round. After adjusting for age, education, and perceived income inadequacy, African American women tended to have an increased risk of becoming disabled if preclinically disabled than White women.

CONCLUSIONS

Prevention through identification of individuals at an early phase of decline appears to be key to addressing racial disparities in physical disability even in later life.

Indicators of preclinical disability: women's experiences of an aging body

This paper is derived from a larger multimethod longitudinal study of women's bodily experiences and coping practices before the onset of disability. Twelve women participated in repeated performance measures, in-depth interviews of daily life and physically challenging events, and observations of daily activities conducted over 18 months. Interpretive phenomenological analysis of textual data showed that women's bodies provided multiple indicators or symptoms of preclinical disability. These indicators informed the women that their body was out of synch with their environment; conspicuous during social activities; and vulnerable to becoming dependent on others, technology, or assistive devices to accomplish daily activities. Greater attention to bodily indicators or symptoms may offer a practical method for clinicians to identify preclinical disability.

Mobility limitation in self-described well-functioning older adults: importance of endurance walk testing

BACKGROUND

Mobility limitations are prevalent, potentially reversible precursors to mobility loss that may go undetected in older adults. This study evaluates standardized administration of an endurance walk test for identifying unrecognized and impending mobility limitation in community elders.

METHODS

Men and women (1480 and 1576, respectively) aged 70-79 years with no reported mobility limitation participating in the Health, Aging and Body Composition study were administered the Long Distance Corridor Walk. Walk performance was examined to determine unrecognized mobility deficits at baseline and predict new self-recognition of mobility limitation within 2 years.

RESULTS

On testing, 23% and 36% of men and women evidenced mobility deficits defined as a contraindication to exertion, meeting stopping criteria or exceeding 7 minutes to walk 400 m. Unrecognized deficits increased with age and were more prevalent in blacks, smokers, obese individuals, and infrequent walkers. Within 2 years, 21% and 34% of men and women developed newly recognized mobility limitation; those with baseline unrecognized deficits had higher rates, 40% and 54% (p <.001), respectively. For each additional 30 seconds over 5 minutes needed to walk 400 m, likelihood of newly recognized mobility limitation increased by 65% and 37% in men and women independent of age, race, obesity, smoking status, habitual walking, reported walking ease, and usual gait speed.

CONCLUSIONS

A sizable proportion of elders who report no walking difficulty have observable deficits in walking performance that precede and predict their recognition of mobility limitation. Endurance walk testing can help identify these deficits and provide the basis for treatment to delay progression of mobility loss.

Subclinical disability in valued life activities among individuals with rheumatoid arthritis

OBJECTIVE

Subclinical disability, the need for modifications in task performance or frequency without reported difficulty with the task, has been identified as a stage along the disability continuum. We estimated the prevalence of subclinical disability in valued life activities (VLAs) among individuals with rheumatoid arthritis (RA), identified characteristics of individuals with VLA subclinical disability, and estimated the ability of VLA subclinical disability to predict later decrements in functioning.

METHODS

Data were from 3 years of a longitudinal panel study of individuals with RA, for which annual structured telephone interviews are conducted (n=508 in year 1, n=442 in year 3). Respondents rated difficulty in VLAs and then reported whether they used any of 4 behavioral modifications (limitations, extra time, help, or equipment) for each. Subclinical disability was defined for each VLA as no reported difficulty with use of any modification. Multiple regression analyses identified predictors of subclinical disability in year 1 and the role of year 1 subclinical disability in development of overt disability between year 1 and year 3.

RESULTS

Almost three-quarters of the subjects exhibited subclinical disability in at least 1 VLA in year 1. Duration of RA was consistently associated with subclinical disability. Individuals with subclinical disability at baseline were significantly more likely to experience increases in functional limitations (odds ratio [OR] 1.09, 95% confidence interval [95% CI] 1.01-1.18) and VLA disability (OR 1.14, 95% CI 1.06-1.23) over a prospective 2-year period.

CONCLUSION

Subclinical disability may be a valuable marker of individuals in a disability transition phase who are particularly susceptible to intervention that would enable them to maintain functioning.

Adverse outcomes and correlates of change in the Short Physical Performance Battery over 36 months in the African American health project

BACKGROUND

The Short Physical Performance Battery (SPPB) is a well-established measure of lower body physical functioning in older persons but has not been adequately examined in African Americans or younger persons. Moreover, factors associated with changes in SPPB over time have not been reported.

METHODS

A representative sample of 998 African Americans (49-65 years old at baseline) living in St. Louis, Missouri were followed for 36 months to examine the predictive validity of SPPB in this population and identify factors associated with changes in SPPB. SPPB was calibrated to this population, ranged from 0 (worst) to 12 (best), and required imputation for about 50% of scores. Adverse outcomes of baseline SPPB included death, nursing home placement, hospitalization, physician visits, incident basic and instrumental activity of daily living disabilities, and functional limitations. Changes in SPPB over 36 months were modeled.

RESULTS

Adjusted for appropriate covariates, weighted appropriately, and using propensity scores to address potential selection bias, baseline SPPB scores were associated with all adverse outcomes except physician visits, and were marginally associated with hospitalization. Declines in SPPB scores were associated with low falls efficacy (b = -1.311), perceived income adequacy (-0.121), older age (-0.073 per year), poor vision (-0.754), diabetes mellitus (-0.565), refusal to report household income (1.48), ever had Medicaid insurance (-0.610), obesity (-0.437), hospitalization in the prior year (-0.521), and kidney disease (-.956).

CONCLUSIONS

The effect of baseline SPPB on adverse outcomes in this late middle-age African American population confirms reports involving older, primarily white participants. Alleviating deterioration in lower body physical functioning guided by the associated covariates may avoid or delay multiple age-associated adverse outcomes.

Preclinical disability as a risk factor for falls in community-dwelling older adults

BACKGROUND

Falls are common and serious problems in older adults. The goal of this study was to examine whether preclinical disability predicts incident falls in a European population of community-dwelling older adults.

METHODS

Secondary data analysis was performed on a population-based longitudinal study of 1644 community-dwelling older adults living in London, U.K.; Hamburg, Germany; Solothurn, Switzerland. Data were collected at baseline and 1-year follow-up using a self-administered multidimensional health risk appraisal questionnaire, including validated questions on falls, mobility disability status (high function, preclinical disability, task difficulty), and demographic and health-related characteristics. Associations were evaluated using bivariate and multivariate logistic regression analyses.

RESULTS

Overall incidence of falls was 24%, and increased by worsening mobility disability status: high function (17%), preclinical disability (32%), task difficulty (40%), test-of-trend p <.003. In multivariate analysis adjusting for other fall risk factors, preclinical disability (odds ratio [OR] = 1.7, 95% confidence interval [CI], 1.1-2.5), task difficulty (OR = 1.7, 95% CI, 1.1-2.6) and history of falls (OR = 4.7, 95% CI, 3.5-6.3) were the strongest significant predictors of falls. In stratified multivariate analyses, preclinical disability equally predicted falls in participants with (OR = 1.7, 95% CI, 1.0-3.0) and without history of falls (OR = 1.8, 95% CI, 1.1-3.0).

CONCLUSIONS

This study provides longitudinal evidence that self-reported preclinical disability predicts incident falls at 1-year follow-up independent of other self-reported fall risk factors. Multidimensional geriatric assessment that includes preclinical disability may provide a unique early warning system as well as potential targets for intervention.