Cognitive Change In Older Adults Research Articles

Intraindividual variability is related to cognitive change in older adults: Evidence for within-person coupling.

In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability.

Predicting Cognitive Change in Older Adults: The Relative Contribution of Practice Effects

Assessing cognitive change in older adults is a common use of neuropsychological services, and neuropsychologists have utilized several strategies to determine if a change is "real," "reliable," and "meaningful." Although standardized regression-based (SRB) prediction formulas may be useful in determining change, SRBs have not been widely applied to older adults. The current study sought to develop SRB formulas on a group of 127 community-dwelling older adults for several widely used neuropsychological measures. In addition to baseline test scores and demographic information, the current study also examined the role of short-term practice effects in predicting test scores after 1 year. Consistent with prior research on younger adults, baseline test performances were the strongest predictors of future test performances, accounting for 25%-58% of the variance. Short-term practice effects significantly added to the predictability of all nine of the cognitive tests examined (3%-22%). Future studies should continue extending SRB methodology for older adults, and the inclusion of practice effects appears to add to the prediction of future cognition.

Total and Regional Adiposity and Cognitive Change in Older Adults

To investigate whether total and/or regional adiposity measured by anthropometry and radiographic studies influences cognitive decline in older adults and whether this association is explained by hormones and inflammatory factors known to be secreted by adipose tissue. Prospective cohort study. Two clinical centers. Three thousand fifty-four elderly individuals enrolled in the Health ABC Study. Adiposity measures included body mass index, waist circumference, sagittal diameter, total fat mass by dual-energy x-ray absorptiometry, and subcutaneous and visceral fat by abdominal computed tomography. We examined the association between baseline body fat measures and change in Modified Mini-Mental State Examination (3MS) score, sequentially adjusting for confounding and mediating variables, including comorbid diseases, adipocytokines, and sex hormones. Main Outcome Measure Scores from the 3MS, administered at the first, third, fifth, and eighth annual clinical examinations. All baseline adiposity measures varied significantly by sex. In mixed-effects models, the association between total and regional adiposity and change in 3MS score varied significantly by sex, with the highest adiposity tertile being associated with greater cognitive declines in men (for each adiposity measure, P < .05) but not in women (for interaction, P < .05). Total fat mass was significantly associated with greater change in 3MS scores among men (lowest tertile, -1.6; middle tertile, -2.2; highest tertile, -2.7; P = .006), even after adjusting for mediators. Higher levels of all adiposity measures were associated with worsening cognitive function in men after controlling for metabolic disorders, adipocytokines, and sex hormone levels. Conversely, there was no association between adiposity and cognitive change in women.

The Association Between Social Resources and Cognitive Change in Older Adults: Evidence From the Charlotte County Healthy Aging Study

We examined associations between multiple aspects of social resources and 5-year change in performance on different domains of cognitive function. Results indicated that lower satisfaction with support was associated with decline in episodic memory performance over 5 years. We also found significant interactions between age and social networks of family and friends and satisfaction with support for the separate cognitive domains. The results suggest that social resources may be differentially important for cognitive change but that different cognitive domains respond in a similar pattern to social resources.

The association between change in motor function and cognition in older adults: a descriptive review

Purpose: This paper provides a descriptive review of research in the area of motor functioning in older adults with mild cognitive impairment (MCI) and early Alzheimer's disease (AD). The specific aims of this paper are to examine: (1) the correlation between clinical measures of motor function and cognitive change in older adults; (2) clinical measures of motor function as predictors of conversion to cognitive impairment in healthy older adults and progression of cognitive impairment in people with MCI; (3) clinical measures of motor function as predictors of rate of decline in cognitive function in healthy older adults, people with MCI, and those with early AD. An additional objective is to discuss the relevance of this information to the practice of physical therapy.Methods: A literature search was conducted using Psych Info, CINAHL, Medline and Pubmed databases. Mild cognitive impairment (MCI), AD and cog* were each combined with gait, balance, fine motor, gross motor and extrapyramidal signs. Studies were included if they met the inclusion and exclusion criteria for the current review.Results: Review of the literature revealed that various domains of physical function such as gait, balance, fine and gross motor skills, and extrapyramidal signs change in tandem with or as a predecessor to declines in cognitive impairment. Furthermore, measures in several of these domains have been found to be predictive of future cognitive and functional decline in nondemented adults as well as those with MCI.Conclusions: Identification of specific motor impairments may differentiate between cognitively unimpaired older adults and those with MCI or AD. These impairments may also predict future cognitive decline and increase diagnostic sensitivity when included in cognitive assessment batteries, thus providing increased opportunities for early intervention.

Measuring cognitive change in older adults. Do reliable change indices of the SIDAM predict dementia?

In persons free of dementia, accelerated cognitive decline might be an indicator of pathological impairment and a potential predictor of future dementia. However, the reliable detection of cognitive decline is a challenging task in some cases. Changes in psychometric test scores do not necessarily result from 'true' clinical change and may result from factors like measurement error and regression to the mean. Reliable Change Indices (RCI) facilitate the interpretation of changes in psychometric test scores. However, it is unknown whether RCI predict future dementia in persons who are presently free of dementia. To examine for a widely used screening instrument for cognitive impairment and dementia (SIDAM) whether RCI methods contribute to the prediction of dementia diagnosis in older adults who are presently free of dementia. A sample of 554 elderly individuals aged 75 and over who participated in the Leipzig Longitudinal Study of the Aged (LEILA 75+) and had no diagnosis of dementia at the first two visits. Participants have been tested with the test part of the SIDAM at maximal six visits with 1.5 year intervals. In all participants, RCI for change in SIDAM score (Time 1 to Time 2) have been computed. The main outcome measure was the diagnosis of dementia. ROC analyses showed that RCI were significant predictors of future dementia. Participants who deteriorated in SIDAM score -4 points or more had a three-fold increased risk of developing dementia (odds ratio 2.71, CI 1.6 to 4.6). However, RCI were not independent predictors of dementia in multivariate analysis. RCI may support the early diagnosis of dementia.

Depressive Symptoms as a Predictor of Cognitive Decline: MacArthur Studies of Successful Aging

The prevalence of dementia continues to rise, and yet, there are few known modifiable risk factors. Depression, as a treatable condition, may be important in the development of dementia. Our objective was to examine the association between depressive symptoms and longitudinal cognitive changes in older adults who were high-functioning at baseline. The authors analyzed data from a community-based cohort (aged 70-79 at baseline), who, at study entry, scored 7 or more (out of 9) on the Short Portable Mental Status Questionnaire (SPMSQ). Depressive symptoms were assessed at baseline using the depression subscale of the Hopkins Symptom Check List. Cognitive performance was measured at baseline and at seven-year follow up by the SPMSQ and by summary scores from standard tests of naming, construction, spatial recognition, abstraction, and delayed recall. After adjusting for potential confounders, including age, education, and chronic health conditions such as diabetes, heart attack, stroke, and hypertension, a higher number of baseline depressive symptoms were strongly associated with greater seven-year decline in cognitive performance and with higher odds of incident cognitive impairment, i.e., decline in SPMSQ score to < or = 6 (adjusted odds ratio per quartile of depressive symptoms score: 1.34, 95% confidence interval: 1.10-1.68). Depressive symptomatology independently predicts cognitive decline and incident cognitive impairment in previously high-functioning older persons.

Measuring cognitive change in older adults: reliable change indices for the Mini-Mental State Examination

Background:In clinical and research settings, the Mini-Mental State Examination (MMSE) is commonly used to measure cognitive change over time. The interpretation of changes in MMSE is often difficult. They do...

Measuring cognitive change in older adults: reliable change indices for the SIDAM

In clinical settings, neuropsychological tests and screening instruments are often used to measure cognitive change over time. However, the interpretation of changes in test scores is often difficult. For most instruments there is no information how much change occurs normally in cognitively healthy individuals. To examine what is a reliable change for a widely used screening instrument for cognitive impairment and dementia. A Sample of 119 cognitively normal elderly individuals aged 75 and over participated in the Leipzig Longitudinal Study of the Aged (LEILA 75+). All participants have been tested six times at 1.5 year intervals with the test part of the SIDAM over a mean period of 7.1 years. Reliable change indices (RCI) were computed for a common confidence interval (90%). It is demonstrated how to compute RCI for individual patients. In repeated assessments with 1.5 year intervals, a change in SIDAM score of at least 4 to 7 points (dependent on which of the six assessments were compared) indicates a reliable change at the 90% confidence level. Smaller changes can be interpreted only with high uncertainty. The interpretation of changes in test scores in older adults should account for potential practice effect, normal decline and regression to the mean.

General Lifestyle Activities as a Predictor of Current Cognition and Cognitive Change in Older Adults: A Cross-Sectional and Longitudinal Examination

General lifestyle activities were examined as a predictor of current cognition and cognitive change over a 6-year interval in older adults. Participants were drawn from a population-based longitudinal study, and they completed the Adelaide Activities Profile and a battery of tests measuring cognition and sensory functioning. Hierarchical regression analyses revealed that, after sensory functioning was controlled for, activity was a significant predictor of current levels of speed, picture naming, incidental recall, and verbal fluency, and of cognitive change in speed, picture naming, and incidental recall. Commonality analyses demonstrated that activity accounted for a notable amount of the total variance in cognition, and that there was prominent overlap in shared variance between activity and age, and between sensory functioning and age. These findings suggest that engaging in general lifestyle activities may help to promote successful cognitive aging.

A comparison of methods for measuring cognitive change in older adults

Well-researched statistical methods are required to guide clinicians in determining the significance of test score changes in serial neuropsychological assessment of older adults. The following six change score methods were examined using five-year test–retest data from the Canadian Study of Health and Aging: the standard deviation method, three reliable change indices (RCIs), and two standardized regression-based methods. Changes in scores on four memory measures were examined in cognitively healthy older adults, and the RCI with a correction for practice/aging effects most accurately classified this normal variability. Diagnostic change (i.e., developing dementia versus remaining cognitive healthy) was also examined in relation to memory test score changes. All change score methods were significantly associated with diagnostic change, though the strength of association varied by measure and method. In contrast to some previous research, RCIs were found to be useful when making diagnostic discriminations in older adults.

Biological Age and 12-Year Cognitive Change in Older Adults: Findings from the Victoria Longitudinal Study

Background: Although recent cross-sectional findings indicate that markers of biological age (BA) mediate chronological age (CA) differences in cognitive performance, little is known about their influence on actual cognitive changes. Objective: The purpose of this investigation is to examine CA and BA as predictors of 12-year cognitive change in a longitudinal sample of older adults. Methods: Data from the Victoria Longitudinal Study (VLS) were examined for 125 adults between 67 and 95 years of age. Biomarkers, including visual and auditory acuity, grip strength, peak expiratory flow, blood pressure, and body mass index, were submitted to a factor analysis and a composite BA variable was computed based on factor loadings. Intraindividual change across 5 waves of measurement (3-year intervals) was examined as a function of CA and BA for 5 cognitive domains: verbal processing speed, working memory, reasoning, episodic memory, and semantic memory. Results: The latent structure of biomarkers was consistent with previous investigations of functional age and a common factor view of biological aging. Results of hierarchical linear modeling showed that BA predicted actual cognitive change (decline) independent of CA. Conclusions: As a predictor of cognitive performance in late life, CA is a proxy for biological and environmental influences. We have shown that biological influences are independent predictors of actual cognitive change in older adults. This supports the view that cognitive decline is not due to aging per se, but rather is likely due to causal factors that operate along the age continuum.

Correlated and coupled cognitive change in older adults with and without preclinical dementia.

Common factor aging theories state that correlations among cognitive age effects signify a single underlying causal process. The logic underlying this proposition was evaluated by examining correlated cognitive change in a sample of 391 initially nondemented older adults who were tested annually for up to 16 years. Between-person correlations among rates of change (range = .56-.61) were partly attributable to model misspecification and the aggregation of heterogeneous groups of individuals. Correlated within-person cognitive change was much stronger in the cases (.45-.51) than in the noncases (.07-.18). These results demonstrate that correlated change may either signify causal commonality or the cumulative effects of multiple age-related conditions that can affect multiple cognitive systems.

Deciphering the 4 D's: cognitive decline, delirium, depression and dementia--a review.

The purpose of this paper is to assist advanced practice nurses to recognize, identify, and diagnose cognitive change in older adults. Optimal cognitive function is important for continued independence, and yet changes in cognition are frequently unrecognized among older adults. Cognitive change in older adults can be observed due to age-related cognitive decline, the development of acute confusion (delirium), depression, dementia and/or a combination of these. When the aetiological source for alterations in cognitive function is delirium or depression, the potential for reversibility mandates that the reason for the cognitive change be identified with steps taken to remedy the situation. Also, early recognition of dementia is an important factor in obtaining timely and appropriate care. These conditions can exist concurrently and may fluctuate making deciphering the reason for the cognitive change problematic. It is essential to understand how the 4 'D's' are expressed and to recognize the potential contributing factors to an observable change in cognitive function for diagnosis and treatment. Recommendations for obtaining a person's history are included.

Detecting Subclinical Change in Cognitive Functioning in Older Adults: Part I: Explication of the Method

This research reports on the practicality of performing repeated measures of cognitive functioning in older adults. The detection of acute or subacute changes in cognitive functioning in the clinical setting could be facilitated by the development of an objective screening tool. Such a tool would not depend on the observation of symptoms only in pathological states, but rather, would depend on monitoring the cognitive functioning of patients over time. These repeated assessments allow us to define the magnitude of normal fluctuations in performance, thereby allowing us to define the magnitude of change in performance that represents a significant decrement or improvement in functioning. The findings reveal that routine monitoring of cognitive performance could allow identification of acute or subacute cognitive change in older adults.