Cognitive Functioning as a Predictor of Functional Disability in Later Life
ABSTRACT The contribution of cognitive functioning on multiple levels of functional disability and mortality over two years as well as individual activities of daily living (ADLs) and instrumental activities of daily living (IADLs) tasks, in a sample of older U.S. adults was examined.
A total of 4,077 U.S. adults (1,493 males and 2,584 females) aged > or =70 years (mean = 76.35 years) from the Second Longitudinal Study of Aging (1997/1998-1999/2000) were examined using an adapted Telephone Interview of Cognitive Status (TICS), ADLs, and IADLs.
Multivariate logistic regression investigated cognition as a predictor of five mutually exclusive levels of functional disability. People with the lowest level of cognition had greater odds of mortality at follow-up (adjusted odds ratio [AOR] = 2.86, 95% confidence interval [CI] = 1.94-4.20), ADL and IADL disability (AOR = 1.58, 95% CI = 1.15-2.16), ADL disability (AOR = 1.83, 95% CI = 1.27-2.64), or IADL disability (AOR = 1.22, 95% CI = 0.86-1.71) than those who were disability-free. Cognitive functioning was not predictive of individual ADL tasks but was predictive of the IADL tasks of preparing meals, shopping for groceries, managing money, telephone use, light housework, and medications but not heavy housework.
Persons with lower levels of cognitive functioning were more likely to die or become disabled than those with higher levels of cognition. Changes in cognitive functioning might serve as an early indicator of neurologic and medical factors.
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- "There is strong support for targeting patients with DSD at admission to post acute care as a high risk group for poor health outcomes. In these settings persistent cognitive decline is a predictor of functional dependency. When delirium is unresolved, rehabilitation is hampered because the associated cognitive problems (i.e., inattention, disorientation etc) interfere with patients' ability to fully engage in restorative therapies. Our goal is to facilitate maximal rehabilitation benefits so these individuals can return to their homes. "
ABSTRACT: Delirium is a state of confusion characterized by an acute and fluctuating decline in cognitive functioning. Delirium is common and deadly in older adults with dementia, and is often referred to as delirium superimposed on dementia, or DSD. Interventions that treat DSD are not well-developed because the mechanisms involved in its etiology are not completely understood. We have developed a theory-based intervention for DSD that is derived from the literature on cognitive reserve and based on our prior interdisciplinary work on delirium, recreational activities, and cognitive stimulation in people with dementia. Our preliminary work indicate that use of simple, cognitively stimulating activities may help resolve delirium by helping to focus inattention, the primary neuropsychological deficit in delirium. Our primary aim in this trial is to test the efficacy of Recreational Stimulation for Elders as a Vehicle to resolve DSD (RESERVE- DSD). This randomized repeated measures clinical trial will involve participants being recruited and enrolled at the time of admission to post acute care. We will randomize 256 subjects to intervention (RESERVE-DSD) or control (usual care). Intervention subjects will receive 30-minute sessions of tailored cognitively stimulating recreational activities for up to 30 days. We hypothesize that subjects who receive RESERVE-DSD will have: decreased severity and duration of delirium; greater gains in attention, orientation, memory, abstract thinking, and executive functioning; and greater gains in physical function compared to subjects with DSD who receive usual care. We will also evaluate potential moderators of intervention efficacy (lifetime of complex mental activities and APOE status). Our secondary aim is to describe the costs associated with RESERVE-DSD. Our theory-based intervention, which uses simple, inexpensive recreational activities for delivering cognitive stimulation, is innovative because, to our knowledge it has not been tested as a treatment for DSD. This novel intervention for DSD builds on our prior delirium, recreational activity and cognitive stimulation research, and draws support from cognitive reserve theory. ClinicalTrials.gov identifier: NCT01267682Trials 05/2011; 12(1):119. DOI:10.1186/1745-6215-12-119 · 1.73 Impact Factor
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- "Declining or comparatively low cognitive function in older adults is associated with loss of independence in activities of daily living (Greiner et al. 1996; McGuire et al. 2006), nursing home admission (Gaugler et al. 2007; Joray et al. 2004), hospitalization (Chodosh et al. 2004), and mortality (Bassuk et al. 2000; Nguyen et al. 2003). The burden associated with deficits in cognitive function is expected to grow as the global population ages (Ferri et al. 2005), but few interventions to prevent, delay, or halt the progression of cognitive decline are currently available. "
ABSTRACT: Traffic-related particles induce oxidative stress and may exert adverse effects on central nervous system function, which could manifest as cognitive impairment. We assessed the association between black carbon (BC), a marker of traffic-related air pollution, and cognition in older men. A total of 680 men (mean ± SD, 71 ± 7 years of age) from the U.S. Department of Veterans Affairs Normative Aging Study completed a battery of seven cognitive tests at least once between 1996 and 2007. We assessed long-term exposure to traffic-related air pollution using a validated spatiotemporal land-use regression model for BC. The association between BC and cognition was nonlinear, and we log-transformed BC estimates for all analyses [ln(BC)]. In a multivariable-adjusted model, for each doubling in BC on the natural scale, the odds of having a Mini-Mental State Examination (MMSE) score ≤ 25 was 1.3 times higher [95% confidence interval (CI), 1.1 to 1.6]. In a multivariable-adjusted model for global cognitive function, which combined scores from the remaining six tests, a doubling of BC was associated with a 0.054 SD lower test score (95% CI, -0.103 to -0.006), an effect size similar to that observed with a difference in age of 1.9 years in our data. We found no evidence of heterogeneity by cognitive test. In sensitivity analyses adjusting for past lead exposure, the association with MMSE scores was similar (odds ratio = 1.3; 95% CI, 1.1 to 1.7), but the association with global cognition was somewhat attenuated (-0.038 per doubling in BC; 95% CI, -0.089 to 0.012). Ambient traffic-related air pollution was associated with decreased cognitive function in older men.Environmental Health Perspectives 12/2010; 119(5):682-7. DOI:10.1289/ehp.1002767 · 7.98 Impact Factor
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- "Indeed, functional impairment, especially ADL impairment, was more common among subjects who lived with others but nearly half of the individuals with dementia living alone were found to have 2 or more impairments in IADL's. In the Canadian Study of Health and Aging over half of cognitively impaired seniors had some IADL disability (McDowell et al., 2001) and an association between cognitive impairment and functional disability has been reported by others (Scanlon et al., 2007; McGuire et al., 2006). Our findings further suggest that among individuals who are living alone with dementia, problems performing tasks which are critical to daily living may both arise and go undetected. "
ABSTRACT: Approximately 25% of individuals with dementia live alone, yet little is known about the cognitive and functional factors that impact detection of impairment. Subjects with dementia (n = 349) from a community study of dementia management were administered the Mini-mental State Examination (MMSE) and were asked to rate their cognitive status. Each participant's knowledgeable informant (KI) was interviewed to provide information about the subject's mental health and levels of cognitive and functional impairment. Subjects with dementia living alone (n = 97, 27.8%) were compared to subjects living with others (n = 252, 72.2%) regarding functional impairment, psychiatric symptoms, cognitive functioning, and dementia recognition. While subjects with dementia living alone had significantly fewer ADL impairments (p < 0.0001) and less cognitive impairment (p < 0.0001) than subjects with dementia who were living with others, nearly half of subjects living alone had two or more IADL impairments. Both knowledgeable informants (p < 0.001) and primary care physicians (p < 0.009) were less likely to detect dementia in subjects living alone, while 77.3% of subjects with dementia living alone rated their cognitive abilities as "good" or "a little worse". Subjects with dementia living alone and those living with others had similar rates of psychosis (p = 0.2792) and depressive symptoms (p = 0.2076). Lack of awareness of cognitive impairment by individuals with dementia living alone as well as their knowledgeable informants and physicians, combined with frequent functional impairment and psychiatric symptoms, heightens risk for adverse outcomes. These findings underscore the need for increased targeted screening for dementia and functional impairment among older persons living alone.International Psychogeriatrics 08/2010; 22(5):778-84. DOI:10.1017/S1041610209991529 · 1.93 Impact Factor