TRansit ACessibility Tool (TRACT): Developing a novel scoring system for public transportation system accessibility.

Introduction: Although federal laws require equal access to public transportation for people with disabilities, access barriers persist. Lack of sharing accessibility information on public transportation websites restricts people with disabilities from making transportation plans and effectively using public transportation systems. This project aims to document information provided about public transportation systems accessibility and share this information using an open data platform. Methods: We reviewed the top twenty-six public transportation systems in the United States based on federal funding in fiscal year 2020. Information about accessibility was abstracted from each public transportation system website by two independent reviewers from February-March 2022. Informed by universal design principles, public transportation systems were scored across six dimensions: facility accessibility (0-22 points), vehicle accessibility (0-11 points), inclusive policies (0-12 points), rider accommodations (0-9 points), paratransit services (0-6 points), and website accessibility (0-2 points). Total scores were calculated as the sum of each dimension (0-62 points). Data and findings were publicly disseminated (https://disabilityhealth.jhu.edu/transitdashboard/). Results: The average overall accessibility information score was 31.9 (SD=6.2) out of 62 possible points. Mean scores were 8.4 (SD=2.9) for facility accessibility, 4.5 (SD=2.1) for vehicle accessibility, 7.8 (SD=1.6) for inclusive policies, 4.9 (SD=1.6) for rider accommodations, 4.5 (SD=2.0) for paratransit services, and 1.8 (SD=0.4) for website accessibility. Eleven public transportation systems (42%) received the maximum score for paratransit services and 20 (77%) received the maximum score for website accessibility. No public transportation system received the maximum score for any of the other dimensions. Conclusions: Using a novel scoring system, we found significant variation in the accessibility information presented on public transportation system websites. Websites are a primary mode where users obtain objective information about public transportation systems and are therefore important platforms for communication. Absence of accessibility information creates barriers for the disability community and restricts equal access to public transportation.

Validation of a Zio XT Patch Accelerometer for the Objective Assessment of Physical Activity in the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Combination devices to monitor heart rate/rhythms and physical activity are becoming increasingly popular in research and clinical settings. The Zio XT Patch (iRhythm Technologies, San Francisco, CA, USA) is US Food and Drug Administration (FDA)-approved for monitoring heart rhythms, but the validity of its accelerometer for assessing physical activity is unknown. OBJECTIVE: To validate the accelerometer in the Zio XT Patch for measuring physical activity against the widely-used ActiGraph GT3X. METHODS: The Zio XT and ActiGraph wGT3X-BT (Actigraph, Pensacola, FL, USA) were worn simultaneously in two separately-funded ancillary studies to Visit 6 of the Atherosclerosis Risk in Communities (ARIC) Study (2016-2017). Zio XT was worn on the chest and ActiGraph was worn on the hip. Raw accelerometer data were summarized using mean absolute deviation (MAD) for six different epoch lengths (1-min, 5-min, 10-min, 30-min, 1-h, and 2-h). Participants who had ≥3 days of at least 10 h of valid data between 7 a.m-11 p.m were included. Agreement of epoch-level MAD between the two devices was evaluated using correlation and mean squared error (MSE). RESULTS: Among 257 participants (average age: 78.5 ± 4.7 years; 59.1% female), there were strong correlations between MAD values from Zio XT and ActiGraph (average r: 1-min: 0.66, 5-min: 0.90, 10-min: 0.93, 30-min: 0.93, 1-h: 0.89, 2-h: 0.82), with relatively low error values (Average MSE × 106: 1-min: 349.37 g, 5-min: 86.25 g, 10-min: 56.80 g, 30-min: 45.46 g, 1-h: 52.56 g, 2-h: 54.58 g). CONCLUSIONS: These findings suggest that Zio XT accelerometry is valid for measuring duration, frequency, and intensity of physical activity within time epochs of 5-min to 2-h.

Hearing loss and cognition: A protocol for ensuring speech understanding before neurocognitive assessment.

INTRODUCTION: Many neurocognitive evaluations involve auditory stimuli, yet there are no standard testing guidelines for individuals with hearing loss. The ensuring speech understanding (ESU) test was developed to confirm speech understanding and determine whether hearing accommodations are necessary for neurocognitive testing. METHODS: Hearing was assessed using audiometry. The probability of ESU test failure by hearing status was estimated in 2679 participants (mean age: 81.4 ± 4.6 years) using multivariate logistic regression. RESULTS: Only 2.2% (N = 58) of participants failed the ESU test. The probability of failure increased with hearing loss severity; similar results were observed for those with and without mild cognitive impairment or dementia. DISCUSSION: The ESU test is appropriate for individuals who have variable degrees of hearing loss and cognitive function. This test can be used prior to neurocognitive testing to help reduce the risk of hearing loss and compromised auditory access to speech stimuli causing poorer performance on neurocognitive evaluation.

Social Factors and Older Adults' Use of Wearable Activity Trackers: Before and During the First Wave of the COVID-19 Pandemic.

Wearable activity trackers (WAT) have shown high potential to improve health in the aging population. Evidence links various social factors with WAT use in older adults, but mainly within small samples and the prevalence of their WAT use during the COVID-19 is unknown. We reported WAT use prevalence before and during the first wave of COVID-19 and examined social factors associated with WAT use frequency using a nationally representative sample of 3302 U.S. older adults. We used Multinomial Logistic Regression to identify social factors associated with WAT use frequency. Only 10.3% of pre-COVID-19 and 10.9% of first-wave subsamples were frequent WAT users. Older adults aged 75 and above and those with low incomes were less likely to frequently use WATs. Our findings suggest socioeconomic and age disparities in WAT use among older Americans. Future studies should focus on enhancing low-income older adults' WAT adoption to enable equal access to WAT-related health benefits.

Prevalence of Hearing Loss and Hearing Aid Use Among US Medicare Beneficiaries Aged 71 Years and Older.

Importance: National prevalence estimates are needed to guide and benchmark initiatives to address hearing loss. However, current estimates are not based on samples that include representation of the oldest old US individuals (ie, aged ≥80 years), who are most at-risk of having hearing loss. Objective: To estimate the prevalence of hearing loss and hearing aid use by age and demographic covariates in a large, nationally representative sample of adults aged 71 years and older. Design, Setting, and Participants: In this cohort study, prevalence estimates of hearing loss by age, gender, race and ethnicity, education, and income were computed using data from the 2021 National Health Aging and Trends Study. Survey weights were applied to produce nationally representative estimates to the US older population. Data were collected from June to November 2021 and were analyzed from November to December 2022. Main Outcomes and Measures: Criterion-standard audiometric measures of hearing loss and self-reported hearing aid use. Results: In this nationally representative sample of 2803 participants (weighted estimate, 33.1 million individuals) aged 71 years or older, 38.3% (95% CI, 35.5%-41.1%) were aged 71 to 74 years, 36.0% (95% CI, 33.1%-38.8%) were aged 75 to 79 years, 13.8% (95% CI, 12.6%-14.9%) were aged 80 to 84 years, 7.9% (95% CI, 7.2%-8.6%) were aged 85 to 89 years, and 4.0% (95% CI, 3.5%-4.6%) were aged 90 years or older; 53.5% (95% CI, 50.9%-56.1%) were female and 46.5% (95% CI, 43.9%-49.1%) were male; and 7.5% (95% CI, 6.2%-8.7%) were Black, 6.5% (95% CI, 4.4%-8.7%) were Hispanic, and 82.7% (95% CI, 79.7%-85.6%) were White. An estimated 65.3% of adults 71 years and older (weighted estimate, 21.5 million individuals) had at least some degree of hearing loss (mild, 37.0% [95% CI, 34.7%-39.4%]; moderate, 24.1% [95% CI, 21.9%-26.4%]; and severe, 4.2% [95% CI, 3.3%-5.3%]). The prevalence was higher among White, male, lower-income, and lower education attainment subpopulations and increased with age, such that 96.2% (95% CI, 93.9%-98.6%) of adults aged 90 years and older had hearing loss. Among those with hearing loss, only 29.2% (weighted estimate, 6.4 million individuals) used hearing aids, with lower estimates among Black and Hispanic individuals and low-income individuals. Conclusions and Relevance: These findings suggest that bilateral hearing loss is nearly ubiquitous among older US individuals, prevalence and severity increase with age, and hearing aid use is low. Deeper consideration of discrete severity measures of hearing loss in this population, rather than binary hearing loss terminology, is warranted.

Validation of accelerometer placement to capture energy expenditure using doubly labeled water.

This study compared accelerometer-measured physical activity by body placement to daily total energy expenditure (TEE) and activity energy expenditure (AEE) measured using doubly labeled water (DLW). Forty-nine adult participants wore accelerometers placed on the nondominant wrist, dominant wrist, and chest while also undergoing DLW assessments. In adjusted models, wrist-measured physical activity (p < 0.05), but not chest-measured physical activity (p > 0.05), was associated with TEE and AEE and explained a significant amount of variance that was not explained by age, sex, height, or body composition (R2 change = 0.04-0.08; all p < 0.05). Accelerometer placement location is an important consideration when using accelerometry to provide information about energy expenditure.

Energetic Cost of Walking and Brain Atrophy in Mid-to-Late Life.

BACKGROUND: Higher energetic costs for mobility are associated with declining gait speed, and slow gait is linked to cognitive decline and Alzheimer's disease. However, the physiological underpinnings of gait and brain health have not been well explored. We examined the associations of the energetic cost of walking with brain volume in cognitively unimpaired adults from the Baltimore Longitudinal Study of Aging. METHODS: We used brain magnetic resonance imaging (MRI) data from 850 participants (mean baseline age 66.3 ± 14.5 years), of whom 451 had longitudinal MRI data (2.8 ± 1.0 MRI scans over 4.0 ± 2.0 years). The energetic cost of walking was assessed as the average energy expended (V̇O2) during 2.5 minutes of customary-paced overground walking. Multivariable linear mixed-effects models examined the associations between baseline energetic cost of walking and regional brain volumes adjusting for covariates. RESULTS: At baseline, higher energetic cost of walking was cross-sectionally associated with lower gray and white matter volumes within the frontal, parietal, and temporal lobes, as well as hippocampal, total brain, and larger ventricular volumes (all false-discovery rate [FDR] p < .05). A baseline energetic cost of walking × time interaction demonstrated that participants with higher energetic cost of walking had faster annual decline in hippocampal volume (FDR p = .02) and accelerated annual increase in ventricular volumes (FDR p = .02). CONCLUSIONS: The energetic cost of walking is associated with gray and white matter volumes and subsequent hippocampal atrophy and ventricular enlargement. Collectively, these data suggest the energetic cost of walking may be an early marker of neurodegeneration that contributes to the gait brain connection.

Assessment of Physical Activity in Adults Using Wrist Accelerometers.

The health benefits of physical activity (PA) have been widely recognized, yet traditional measures of PA, including questionnaires and category-based assessments of volume and intensity, provide only broad estimates of daily activities. Accelerometers have advanced epidemiologic research on PA by providing objective and continuous measurement of PA in free-living conditions. Wrist-worn accelerometers have become especially popular because of low participant burden. However, the validity and reliability of wrist-worn devices for adults have yet to be summarized. Moreover, accelerometer data provide rich information on how PA is accumulated throughout the day, but only a small portion of these rich data have been used by researchers. Last, new methodological developments are emerging that aim to overcome some of the limitations of accelerometers. In this review, we provide an overview of accelerometry research, with a special focus on wrist-worn accelerometers. We describe briefly how accelerometers work; summarize the validity and reliability of wrist-worn accelerometers; discuss the benefits of accelerometers, including measuring light-intensity PA; and discuss pattern metrics of daily PA recently introduced in the literature. A summary of large-scale cohort studies and randomized trials that implemented wrist-worn accelerometry is provided. We conclude the review by discussing new developments and directions of research using accelerometers, with a focus on wrist-worn accelerometers.

Pain Provocation and the Energy Cost of Walking: A Matched Comparison Study of Older Adults With and Without Chronic Low Back Pain With Radiculopathy.

BACKGROUND AND PURPOSE: Chronic low back pain with radiculopathy (CLBPR) is common among older adults and can lead to walking difficulty. Energy cost of walking strongly predicts changes in walking speed, which is predictive of mortality in older adults. The purposes of this study were to examine (1) the impact of pain provocation on the energy cost of walking and (2) the relationship between pain intensity and change in energy cost of walking. METHODS: Older adults (60-85 years) with (n = 20) and without (n = 20) CLBPR were matched on age, sex, and diabetes presence/absence. Energy cost of walking was measured with a portable metabolic gas analyzer, as participants walked for 20 minutes or less. Energy cost and pain measurements occurred during early and late stages of walking. Percent change in energy cost was calculated. Participants were grouped by their pain response during walking: increased pain (n = 13); consistent pain (n = 7); no pain, matched to individuals with increased pain (n = 13); and no pain, matched to individuals with consistent pain (n = 7). We examined the within-groups change in energy cost for all groups, as well as the relationship between late-stage pain intensity and percent change of energy cost for individuals whose pain increased. RESULTS AND DISCUSSION: Within the increased pain group, energy cost of walking significantly increased from early to late stages (median change = 0.003 mL/kg/m, P = .006), and late-stage pain intensity explained 41.2% (p = 0.040) of the variance in percent change. Since pain appears to be linked to energy cost, effective pain management with walking may be an important factor in preventing mobility decline. CONCLUSIONS: Among older adults with CLBPR, pain provocation drives increases in the energy cost of walking. Because high energy cost of walking is predictive of mobility decline, clinicians may focus on effective pain management strategies during walking, which may potentially decrease the risk of mobility decline.

The Health of America's Aging Prison Population.

Older incarcerated individuals comprise the fastest growing demographic in the US prison system. Unhealthy lifestyles among incarcerated individuals and inadequate health care lead to earlier onset and more rapid progression of many chronic conditions that are prevalent among community-living older adults. There are limited peer-reviewed epidemiologic data in this area; however, there is growing interest in identifying strategies for housing aging incarcerated individuals, delivering appropriate health care in prisons, and coordinating after-release health care. In this systematic review, we summarize the epidemiologic evidence of the health challenges facing the aging US prison population. Our comprehensive literature search focused on health outcomes, including diseases, comorbid conditions, mental health, cognition, and mobility. From 12,486 articles identified from the literature search, we reviewed 21 studies published between 2007 and 2017. All the studies were observational and cross-sectional, and most (n = 17) were based on regional samples. Sample sizes varied widely, ranging from 25 to 14,499 incarcerated people (median, 258). In general, compared with their younger counterparts, older incarcerated individuals reported high rates of diabetes mellitus, cardiovascular conditions, and liver disease. Mental health problems were common, especially anxiety, fear of desire for death or suicide, and depression. Activities of daily living were challenging for up to one-fifth of the population. We found no empirical data on cognition among older incarcerated individuals. The findings of this review reveal few empirical data in this area and highlight the need for new data to drive policy and practice patterns that address critical health issues related to the aging prison population.

Rising Energetic Cost of Walking Predicts Gait Speed Decline With Aging.

BACKGROUND: Slow gait is a robust biomarker of health and a predictor of functional decline and death in older adults, yet factors contributing to the decline in gait speed with aging are not well understood. Previous research suggests that the energetic cost of walking at preferred speed is inversely associated with gait speed, but whether individuals with a rising energetic cost of walking experience a steeper rate of gait speed decline has not been investigated. METHODS: In participants of the Baltimore Longitudinal Study of Aging, the energetic cost of overground walking at preferred speed (mL/kg/m) was assessed between 2007 and 2014 using a portable indirect calorimeter. The longitudinal association between the energetic cost of walking and usual gait speed over 6 meters (m/s) was assessed with multivariate linear regression models, and the risk of slow gait (<1.0 m/s) was analyzed using Cox proportional hazards models. RESULTS: The study population consisted of 457 participants aged 40 and older who contributed 1,121 person-visits to the analysis. In fully adjusted models, increases in the energetic cost of walking predicted the rate of gait speed decline in those older than 65 years (ß = -0.008 m/s, p < .001). Moreover, those with a higher energetic cost of walking (>0.17mL/kg/m) had a 57% greater risk of developing slow gait compared with a normal energetic cost of walking (≤0.17mL/kg/m; adjusted hazard ratio = 1.57, 95% confidence interval: 1.01-2.46). CONCLUSIONS: These findings suggest that strategies to maintain walking efficiency hold significant implications for maintaining mobility in late life. Efforts to curb threats to walking efficiency should focus on therapies to treat gait and balance impairments, and reduce clinical disease burden.

Estimating energy expenditure from heart rate in older adults: a case for calibration.

BACKGROUND: Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear. OBJECTIVE: To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using different levels of calibration. DESIGN: Heart rate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heart rate and energy expenditure and cross-validation models assessed predictive performance. RESULTS: Heart rate and energy expenditure were highly correlated (r=0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d. =0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heart rate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min). CONCLUSION: These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heart rate in older adults but caution should be exercised when making inferences at the individual level without proper calibration.

The relationship of the energetic cost of slow walking and peak energy expenditure to gait speed in mid-to-late life.

OBJECTIVE: Peak energy expenditure is highly correlated with usual gait speed; however, it is unknown whether the energetic cost of walking is also an important contributor to usual gait speed when considered as a component of peak walking capacity. DESIGN: The energetic cost of 5 mins of slow treadmill walking (0.67 m/sec), peak overground walking energy expenditure, and usual gait speed over 6 m were assessed cross-sectionally in 405 adults aged 33 to 94 yrs in the Baltimore Longitudinal Study of Aging. RESULTS: Mean (SD) energy expenditures during slow and peak sustained walking were 8.9 (1.4) and 18.38 (4.8) ml kg(-1) min(-1), respectively. Overall, the energetic cost of slow walking as a percentage of peak walking energy expenditure was strongly associated with usual gait speed (P < 0.001); however in stratified analyses, this association was maintained only in those with peak walking capacity below 18.3 ml kg(-1) min(-1) (P = 0.04), the threshold associated with independent living. CONCLUSIONS: In older persons with substantially reduced peak walking capacity, the energetic cost of walking is associated with gait speed, particularly when peak walking capacity nears the minimum level considered necessary for independent living. Thus, optimal habilitation in older frail persons may benefit from both improving fitness and reducing the energetic cost of walking.

The role of energetic cost in the age-related slowing of gait speed.

OBJECTIVES: To determine whether slow gait represents a compensatory strategy to reduce the energetic cost of walking with age. DESIGN: Cross-sectional analysis. SETTING: Community-dwelling volunteers from the Baltimore Longitudinal Study of Aging (BLSA). PARTICIPANTS: Four hundred twenty community-dwelling persons aged 32 to 96 (mean 68.1 ± 12.5) who underwent a physical examination, physical function testing, and energy expenditure assessment. MEASUREMENTS: Energy expenditure per minute (mL/kg/min) and per meter (mL/kg/m) during 2.5 minutes of overground walking at customary speed and usual gait speed over 6 m (m/s) were examined. General linear regression models were used to assess the relationship between customary walking energy expenditure and usual gait speed, adjusted for potential confounders including smoking, medical diagnoses, walking-related pain, and balance difficulty. RESULTS: Usual gait speed was slower with increasing age after age 65. Energy expenditure per minute during customary walking averaged 13.0 ± 2.8 mL/kg/min and was independent of age (ρ < 0.01, P = .88). In contrast, energy expenditure per meter walked was progressively higher after age 65 (ρ = 0.35, P < .001) and heightened after age 80 (r = 0.57, P < .001), mirroring the observed pattern of usual gait speed. This relationship remained significant after adjusting for multiple impairments and comorbidities. CONCLUSION: These observations support the hypothesis that slower gait at older ages may reflect a compensatory action to offset the greater energetic cost of walking associated with aging and chronic conditions. Future studies should evaluate the specific mechanisms that contribute to this phenomenon as novel targets for clinical intervention.

Comparison of the Cosmed K4b(2) portable metabolic system in measuring steady-state walking energy expenditure.

BACKGROUND AND AIMS: Recent introduction of the Cosmed K4b(2) portable metabolic analyzer allows measurement of oxygen consumption outside of a laboratory setting in more typical clinical or household environments and thus may be used to obtain information on the metabolic costs of specific daily life activities. The purpose of this study was to assess the accuracy of the Cosmed K4b(2) portable metabolic analyzer against a traditional, stationary gas exchange system (the Medgraphics D-Series) during steady-state, submaximal walking exercise. METHODS: Nineteen men and women (9 women, 10 men) with an average age of 39.8 years (+/-13.8) completed two 400 meter walk tests using the two systems at a constant, self-selected pace on a treadmill. Average oxygen consumption (VO2) and carbon dioxide production (VCO2) from each walk were compared. RESULTS: Intraclass Correlation Coefficient (ICC) and Pearson correlation coefficients between the two systems for weight indexed VO2 (ml/kg/min), total VO2 (ml/min), and VCO2 (ml/min) ranged from 0.93 to 0.97. Comparison of the average values obtained using the Cosmed K4b(2) and Medgraphics systems using paired t-tests indicate no significant difference for VO2 (ml/kg/min) overall (p = 0.25), or when stratified by sex (p = 0.21 women, p = 0.69 men). The mean difference between analyzers was - 0.296 ml/kg/min (+/-0.26). Results were not significantly different for VO(2) (ml/min) or VCO2) (ml/min) within the study population (p = 0.16 and p = 0.08, respectively), or when stratified by sex (VO(2): p = 0.51 women, p = 0.16 men; VCO2: p = .11 women, p = 0.53 men). CONCLUSION: The Cosmed K4b(2) portable metabolic analyzer provides measures of VO2 and VCO2 during steady-state, submaximal exercise similar to a traditional, stationary gas exchange system.