Social and Neighborhood Context Moderates the Associations Between Processing Speed and Driving Mobility: A 10-year Analysis of the ACTIVE Study.

Objectives: Processing speed is essential to functional independence in later life, such as driving a vehicle. Few studies have examined processing speed and driving mobility in the context of racial differences and social determinants of health (SDoH). This study characterized the longitudinal association between processing speed and driving mobility, and how it varied by race and SDoH. Methods: Using data from the control arm of the Advanced Cognitive Training in Vital Elderly study (n = 581, 24.5% Black), multilevel models examined longitudinal associations between processing speed and driving mobility outcomes (driving space, exposure, and difficulty). Race and SDoH moderations were explored. Results: Decline in processing speed measures was associated with increased self-reported driving difficulty, but only for older adults with below-average to average scores for neighborhood and built environments and social community context SDoH domains. Discussion: Findings emphasize the influence of physical and social environmental characteristics on processing speed and driving mobility.

Rural-Urban Differences in Cognition: Findings From the Advanced Cognitive Training for Independent and Vital Elderly Trial.

ObjectivesWe examined associations between three geographic areas (urban, suburban, rural) and cognition (memory, reasoning, processing speed) over a 10-year period. Methods: Data were obtained from 2539 participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial. Multilevel, mixed-effects linear regression was used to estimate cognitive trajectories by geographical areas over 10 years, after adjusting for social determinants of health. Results: Compared to urban and suburban participants, rural participants fared worse on all cognitive measures-memory (B = -1.17 (0.17)), reasoning (B = -1.55 (0.19)), and processing speed (B = 0.76 (0.19)) across the 10-year trajectory. Across geographic areas, greater economic stability, health care access and quality, and neighborhood resources were associated with better cognition over time. Discussion: Findings highlight the importance of geographical location when examining cognition later in life. More research examining place-based life experiences is needed to make the greatest impact on geographically diverse communities.

Evaluating Social Determinants of Health Domains and Their Predictive Validity Within Black/African American and White Older Adults From the ACTIVE Trial.

OBJECTIVE: To assess domains of social determinants of health (SDoH) and their associations with cognition and quality of life. METHOD: This investigation uses baseline data from individuals participating in the ACTIVE trial (n = 2505) to reproduce the SDoH domains described in Healthy People 2030 (economic stability, health care, education, neighborhood and built environment, and social and community context). Results: Results support using data from the ACTIVE trial to assess all five SDoH domains, and the ability of the composites to predict baseline performance on measures of cognition and self-reported quality of life within a sample of older adults. Additionally, higher SDoH domain scores were associated with better functioning on composite measures of cognition and higher scores for mental and general health-related quality of life with Access to Healthcare associated with all outcomes. Discussion: These findings can inform investigators interested in assessing multiple domains of SDoH and highlight the importance of access to health care within older Black/African American and White older adults.

Longitudinal relationships between subjective fatigue, cognitive function, and everyday functioning in old age.

BACKGROUND: The present study examined the prospective relationships between subjective fatigue, cognitive function, and everyday functioning. METHODS: A cohort study with secondary data analysis was conducted using data from 2,781 community-dwelling older adults without dementia who were enrolled to participate in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomized intervention trial. Measures included demographic and health information at baseline, and annual assessments of subjective fatigue, cognitive function (i.e. speed of processing, memory, and reasoning), and everyday functioning (i.e. everyday speed and everyday problem-solving) over five years. RESULTS: Four distinct classes of subjective fatigue were identified using growth mixture modeling: one group complaining fatigue "some of the time" at baseline but "most of the time" at five-year follow-up (increased fatigue), one complaining fatigue "a good bit of the time" constantly over time (persistent fatigue), one complaining fatigue "most of the time" at baseline but "some of the time" at five-year follow-up (decreased fatigue), and the fourth complaining fatigue "some of the time" constantly over time (persistent energy). All domains of cognitive function and everyday functioning declined significantly over five years; and the decline rates, but not the baseline levels, differed by the latent class of subjective fatigue. Except for the decreased fatigue class, there were different degrees of significant associations between the decline rates of subjective fatigue and all domains of cognitive function and everyday functioning in other classes of subjective fatigue. CONCLUSION: Future interventions should address subjective fatigue when managing cognitive and functional abilities in community-dwelling older adults.

Race-related disparities in 5-year cognitive level and change in untrained ACTIVE participants.

OBJECTIVE: The current study examined a 5-year cognitive change in untrained African American and White participants from the Advanced Cognitive Training in Independent and Vital Elderly (ACTIVE) study. METHOD: Five-year trajectories of memory, reasoning, visual processing speed/useful field of view, digit-symbol substitution, and vocabulary were investigated. Education, health, gender, age, and retest/practice effects were controlled for, and a missing data pattern mixture approach was used to adjust for dropout effects. RESULTS: After considering age, education, health, and gender, being African American uniquely explained 2% to 7% of the variance in cognitive performance. There were virtually no significant race differences in the rates of change. DISCUSSION: Race-related results in the current study are consistent with previous research suggesting that social advantage factors such as education have a stronger influence on the level of performance than the rate of change. The small remaining effects of being African American on performance levels likely reflect uncontrolled variation in factors like literacy and financial advantage.

Awareness of functional difficulties in mild cognitive impairment: a multidomain assessment approach.

OBJECTIVES: To determine whether patients with mild cognitive impairment (MCI) are fully aware of and provide reliable estimates of their functional status. DESIGN: Controlled, matched-samples, cross-sectional study. SETTING: University medical and research centers. PARTICIPANTS: Fifty-seven persons with amnestic MCI and 68 normal controls. MEASUREMENTS: The study examined accuracy of self-report in MCI across five functional domains (driving, financial abilities, medication management, grocery shopping, and telephone use) by comparing patients' report of functioning with their performance on laboratory-based measures of function. RESULTS: The discrepancy between self-report and objective performance was significantly higher in patients with MCI than in their cognitively normal peers only on financial abilities. Patients with MCI overestimated their abilities on this functional domain. Patients with MCI also tended to overestimate their driving abilities, although this was not statistically significant. CONCLUSION: These findings provide evidence that awareness of functional difficulties is not a unitary construct; rather, it varies across functional domains. They also suggest that self-report of functional abilities in MCI may be, on the whole, as accurate as in cognitively intact older adults. Even so, the self-objective discrepancies noted for both study groups suggest that supplementing self-reported information with objective functional assessment might improve detection of older adults who have begun to experience more functional restriction than is normal for age. In turn, timely identification would permit the targeted implementation of interventions that delay or forestall further deterioration in function.

A cost-benefit analysis of risk-reduction strategies targeted at older drivers.

OBJECTIVE: The risk of motor-vehicle collisions increases as driving-related functional abilities decline. These declines can accompany normal or pathological aging and can be identified through driving-related functional screening exams upon license renewal. The objective of this cost-benefit analysis was to determine the utility of four functional screening procedures used to identify drivers at risk for motor-vehicle collisions, as well as an intervention designed to maintain or improve functional abilities. Additionally, this study sought to determine the expected cost per driver if an intervention was designed to target only those drivers who failed the functional ability-based driving screen, versus the expected cost per driver if the intervention was distributed en masse to all drivers 75 years and older. Improving functional abilities in older adults has potential far-reaching health and financial impacts which are broader than their impact of maintaining mobility. METHODS: A decision tree was constructed to evaluate the expected costs and benefits of (a) screening all drivers and intervening when indicated (several screening batteries of varying length were considered), (b) no screening, but intervening with all drivers of older age, or (c) neither screening nor intervening (i.e., re-licensing per usual). Test characteristics and risk probabilities were based on a cohort of drivers aged 75 and older from a previous study (Ball et al., 2006). Relevant sensitivity analyses were conducted. RESULTS: Providing all drivers with the speed-of-processing intervention is the most cost-beneficial option (expected cost per driver = $493.30), even if the cost of the intervention doubles. Sensitivity analysis indicated the effectiveness of the intervention could drop from 86% to 25% and the preventative approach of intervening with all drivers remains the most cost-beneficial strategy. The least cost-beneficial option is almost always re-licensing per usual (expected cost per driver = $1,562.84). CONCLUSION: Screening drivers upon license renewal is not currently beneficial because the available technology cannot consistently identify drivers at risk for a collision. However, the speed-of-processing intervention has demonstrated efficacy in improving driving competence (Roenker et al., 2003) and is a non-invasive, moderate-cost intervention that has the potential to protect the safety and mobility, as well as the financial interests, of older drivers and the community at large.