Exploring Shared Effects of Multisensory Impairment, Physical Dysfunction, and Cognitive Impairment on Physical Activity: An Observational Study in a National Sample.

Multisensory, physical, and cognitive dysfunction share age-related physiologic disturbances and may have common health effects. We determined whether the effect of multisensory impairment on physical activity (PA) is explained by physical (timed up and go) or cognitive (Short Portable Mental Status Questionnaire) dysfunction. A National Social Life, Health, and Aging Project participant subset (n = 507) underwent objective sensory testing in 2005-2006 and wrist accelerometry in 2010-2011. We related multisensory impairment to PA using multivariate mixed-effects linear regression and compared the effect magnitude after adjusting for physical then cognitive dysfunction. Worse multisensory impairment predicted lower PA across three scales (Global Sensory Impairment: ß = -0.04, 95% confidence interval [-0.07, -0.02]; Total Sensory Burden: ß = -0.01, 95% confidence interval [-0.03, -0.003]; and Number of Impaired Senses: ß = -0.02, 95% confidence interval [-0.04, -0.004]). Effects were similar after accounting for physical and cognitive dysfunction. Findings suggest that sensory, physical, and cognitive dysfunction have unique mechanisms underlying their PA effects.

Relating wrist accelerometry measures to disability in older adults.

OBJECTIVE: This analysis assessed the extent to which: (1) wrist accelerometer measures were associated with difficulty performing specific activities of daily living and instrumental activities of daily living and (2) these measures contributed important information about disability beyond a typical self-reported vigorous activity frequency question. METHODS: We used data from the National Social Life, Health and Aging Project (NSHAP) accelerometry sub-study (n=738). Activity was assessed using two wrist-accelerometer measures assessed over 3 days (routine activity expressed as mean count/15s epoch during wake time, and immobile time expressed as the proportion of wake time spent immobile), and self-reported average vigorous activity frequency. The association between routine activity, immobile time and difficulty performing fourteen activities of daily living (ADLs) and instrumental activities of daily living (IADLs) plus two summary measures (any ADL or IADL difficulty), was assessed using logistic regression models, with and without controlling for self-reported vigorous activity. RESULTS: Self-reported activity was mildly correlated with routine activity (r=0.27) and immobile time (r=-0.21). Routine activity, immobile time, and self-reported vigorous activity were significantly associated with twelve, ten, and fourteen disability measures, respectively. After controlling for self-reported activity, significant associations remained between routine activity and eight disabilities, and immobile time and six disabilities. CONCLUSION: Wrist accelerometry measures were associated with many ADL and IADL disabilities among older adults. Wrist acclerometry in older adults may be useful to help assess disability risks and set individualized physical activity targets.

Evaluation of a Brief Survey Instrument for Assessing Subtle Differences in Cognitive Function Among Older Adults.

Most measures of cognitive function used in large-scale surveys of older adults have limited ability to detect subtle differences across cognitive domains, and standard clinical instruments are impractical to administer in general surveys. The Montreal Cognitive Assessment (MoCA) can address this need, but has limitations in a survey context. Therefore, we developed a survey adaptation of the MoCA, called the MoCA-SA, and describe its psychometric properties in a large national survey. Using a pretest sample of older adults (n=120), we reduced MoCA administration time by 26%, developed a model to accurately estimate full MoCA scores from the MoCA-SA, and tested the model in an independent clinical sample (n=93). The validated 18-item MoCA-SA was then administered to community-dwelling adults aged 62 to 91 as part of the National Social life Health and Aging Project Wave 2 sample (n=3196). In National Social life Health and Aging Project Wave 2, the MoCA-SA had good internal reliability (Cronbach α=0.76). Using item-response models, survey-adapted items captured a broad range of cognitive abilities and functioned similarly across sex, education, and ethnic groups. Results demonstrate that the MoCA-SA can be administered reliably in a survey setting while preserving sensitivity to a broad range of cognitive abilities and similar performance across demographic subgroups.

Comorbidity and chronic conditions in the National Social Life, Health and Aging Project (NSHAP), Wave 2.

OBJECTIVE: The goals of this paper were: (a) to promote research using the National Social Life, Health and Aging Project (NSHAP) Wave 2 data by providing relevant background information for a broad range of chronic conditions and (b) to provide a framework for combining these chronic conditions into informative comorbidity indices. METHOD: The chronic conditions measured in NSHAP Wave 2 were grouped across several health domains: cardiovascular, endocrine and metabolic, cancer, lung, inflammatory and bone, neurological, and sensorimotor. Prevalences for each condition were reported as percentages and were also estimated separately by age group and gender. Additionally, 2 comorbidity indices were created: a Modified Charlson Comorbidity Index (CCI) that included conditions associated with mortality risk and the NSHAP Comorbidity Index (NCI) that included conditions from the Modified CCI as well as additional conditions related to overall health and function. RESULTS: Hypertension, incontinence, arthritis, heart conditions, cancer, and diabetes were the most prevalent conditions. In general, prevalences of most chronic conditions increased with age. Additionally, there were several notable gender differences in chronic condition prevalence. Due to the inclusion of highly prevalent conditions, such as hypertension and incontinence, the mean comorbidity index score of the NCI was higher than that of the Modified CCI. DISCUSSION: Wave 2 of NSHAP included a variety of measures assessing the chronic conditions that are the most prevalent in older adults. These data are a valuable resource for the study of the impact of chronic conditions on overall health and aging.