Does Cognitive Status Modify the Relationship Between Education and Mortality? Evidence from the Canadian Study of Health and Aging

Background: There is compelling evidence of an inverse relationship between level of education and increased mortality. In contrast to this, one study showed that among subjects with Alzheimer's Disease, those with high education are more than twice as likely to die earlier; however, this result has proven difficult to replicate. We examine the relationship between education and mortality by cognitive status using a large, nationally representative sample of elderly. Methods: A representative sample of 10,263 people aged 65 or over from the 10 Canadian provinces participated in the Canadian Study of Health and Aging in 1991. Information about age, gender, education, and an initial screening for cognitive impairment were collected; those who screened positive for cognitive impairment were referred for a complete clinical and neuropsychological examination, from which cognitive status and clinical severity of dementia were assessed. Vital status and date of death were collected at follow-up in 1996. The analysis was conducted using survival analysis. Findings: Cognitive status modifies the relationship between education and mortality. For those with no cognitive impairment, an inverse relationship between education and mortality exists. Elderly with cognitive impairment but no dementia, or those with dementia, are more likely to die early than the cognitively normal at baseline, but no relationship exists between education and mortality. Interpretation: These findings do not support previous work that showed a higher risk of mortality among highly educated dementia subjects.Alzheimer disease; cognition; dementia; education; epidemiology; etiology; mortality

The Use of Behavior and Mood Medications by Care-recipients in Dementia and Caregiver Depression and Perceived Overall Health

The mental and physical health of dementia caregivers has been shown to be worse than that of non-caregivers. The present study was undertaken to investigate whether the caregivers of persons who take medications for behavior and mood problems in dementia are less depressed, and perceive their overall health to be better, than the caregivers of persons who do not take such medications. Behavior and mood medications include anti-psychotics, anti- depressants, and anti-convulsants. The Canadian Study of Health and Aging was used to identify informal, unpaid caregivers of persons with dementia (i.e., Alzheimer's disease, vascular dementia, or other dementia [e.g., Parkinson's disease]). The caregivers of persons diagnosed with cognitive impairment not dementia or no cognitive impairment were also included in the study. Care-recipient use of behavior and mood medications was not found to affect caregiver depression (OR = 1.02; 95% CI = 0.62 to 1.66) or caregiver's perceived overall health (OR = 1.35; 95% CI = 0.80 to 2.27).dementia; caregiver; medication; behavior; mood

Vitamin D status, cognitive decline and incident dementia : the Canadian Study of Health and Aging

Objective: Vitamin D could prevent cognitive decline because of its neuroprotective, anti-inflammatory and antioxidant properties. This study aimed to evaluate the associations of plasma 25-hydroxyvitamin D (25(OH)D) concentrations with global cognitive function and incident dementia, including Alzheimer’s disease (AD). Methods: The Canadian Study of Health and Aging is a 10-year cohort study of a representative sample of individuals aged 65years or older. A total of 661 subjects initially without dementia with frozen blood samples and follow-up data were included. Global cognitive function was measured using the validated Modified Mini-Mental State (3MS) examination. A consensus diagnosis of all-cause dementia and AD was made between the physician and the neuropsychologist according to published criteria. Cognitive decline for a 5-year increase in age at specific 25(OH)D concentrations was obtained using linear mixedmodels with repeated measures. Hazard ratios of incident dementia and AD were obtained using semi-parametric proportionalhazards models with age as time scale. Results: Over a mean follow-up of 5.4 years, 141 subjects developed dementia of which 100 were AD. Overall, no significant association was found between 25(OH)D and cognitive decline, dementia or AD. Higher 25(OH)D concentrations were associated with an increased risk of dementia and AD in women, but not in men. Conclusion: This study does not support a protective effect of vitamin D status on cognitive function. Further research is needed toclarify the relation by sex.Objectif : La vitamine D pourrait avoir un effet protecteur sur le déclin cognitif en raison de ses propriétés neuroprotectrices, anti-inflammatoires et antioxydantes. L’objectif de cette étude était d’évaluer les associations entre la concentration plasmatique de 25-hydroxyvitamine D (25(OH)D), la fonction cognitive globale et l’incidence de la démence incluant la maladie d’Alzheimer (MA). Méthodes: L’Étude sur la santé et le vieillissement au Canada est une étude de cohorte de 10 ans réalisée dans un échantillon représentatif des Canadiens âgés de 65 ans et plus. Un total de 661 participants sans démence, pour lesquels un échantillon sanguin congelé et des données au suivi étaient disponibles, ont été inclus dans l’analyse. La fonction cognitive globale a été mesurée à l’aide d’un outil validé, le Modified Mini-Mental State(3MS) Examination. Les diagnostics de démence toutes cause set de MA ont été obtenus par consensus entre un médecin généraliste et un neuropsychologue selon des critères publiés. Le déclin cognitif pour chaque augmentation de 5 ans d’âge à des concentrations spécifiques de 25(OH)D a été mesuré à l’aide de modèles linéaires mixtes avec données répétées. Des rapports de risques de la démence et de la MA ont été obtenus à l’aide de modèles à risques proportionnels semi-paramétriques en utilisant l’âge comme échelle du temps. Résultats : En cours de suivi (moyenne : 5,4 ans), 141 individus ont développé une démence dont 100 étaient la MA. Globalement, aucune association statistiquement significative n’a été observée entre le 25(OH)D et le déclin cognitif, la démence ou la MA. Des concentrations plus élevées de 25(OH)D étaient associées à une augmentation du risque de démence et de MA chez les femmes, mais pas chez les hommes. Conclusion : Cette étude n’appuie pas l’hypothèse d’un effet protecteur de la vitamine D sur la fonction cognitive. D’autres études seraient nécessaires pour clarifier la relation selon le sexe

Incidence of dementia and cognitive impairment, not dementia in the united states

Objective: Estimates of incident dementia, and cognitive impairment, not dementia (CIND) (or the related mild cognitive impairment) are important for public health and clinical care policy. In this paper, we report US national incidence rates for dementia and CIND. Methods: Participants in the Aging, Demographic, and Memory Study (ADAMS) were evaluated for cognitive impairment using a comprehensive in‐home assessment. A total of 456 individuals aged 72 years and older, who were not demented at baseline, were followed longitudinally from August 2001 to December 2009. An expert consensus panel assigned a diagnosis of normal cognition, CIND, or dementia and its subtypes. Using a population‐weighted sample, we estimated the incidence of dementia, Alzheimer disease (AD), vascular dementia (VaD), and CIND by age. We also estimated the incidence of progression from CIND to dementia. Results: The incidence of dementia was 33.3 (standard error [SE], 4.2) per 1,000 person‐years and 22.9 (SE, 2.9) per 1,000 person‐years for AD. The incidence of CIND was 60.4 (SE, 7.2) cases per 1,000 person‐years. An estimated 120.3 (SE, 16.9) individuals per 1,000 person‐years progressed from CIND to dementia. Over a 5.9‐year period, about 3.4 million individuals aged 72 and older in the United States developed incident dementia, of whom approximately 2.3 million developed AD, and about 637,000 developed VaD. Over this same period, almost 4.8 million individuals developed incident CIND. Interpretation: The incidence of CIND is greater than the incidence of dementia, and those with CIND are at high risk of progressing to dementia, making CIND a potentially valuable target for treatments aimed at slowing cognitive decline. ANN NEUROL 2011;Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86941/1/22362_ftp.pd

Caregiver Employment Status and Time to Institutionalization of Persons with Dementia

Background - This study was undertaken to examine the association between caregiver employment status and the time to institutionalization of persons with dementia. No study has previously examined this association. Methods - The database of the Canadian Study of Health and Aging was used to obtain data on 326 caregiver/care-recipient dyads. Caregivers were primary, informal carers; care-recipients were diagnosed with dementia and living in the community at baseline. Care-recipients were followed from the date of their baseline screening interview until the date of institutionalization, the date of death before institutionalization, or the date of the 5-year follow-up interview. An accelerated failure time model with a Weibull distribution was used to conduct the survival analysis. Results - During the 5-year follow-up period, 139 care-recipients (45%) were institutionalized; the median time to institutionalization was 1,821 days (95% confidence interval [CI]: 1,539-1,981 days) for the care-recipients of employed caregivers and 1,542 days (95% CI: 1,284-1,653 days) for the care-recipients of unemployed caregivers (p = 0.0634). The adjusted acceleration factor was 1.85 (95% CI: 1.08-3.86), controlling for caregiver thoughts about institutionalizing the care-recipient, caregiver health, and the use of a day center to help provide care. Conclusions - For the care-recipients of employed caregivers, the adjusted time to institutionalization was longer than for the care- recipients of unemployed caregivers.dementia, caregiver, employment, time to institutionalization

Prevalence of five common clinical abnormalities in very elderly people: population based cross sectional study

As the prevalence of disease rises with age, the number of people with unidentified abnormalities is also likely to increase. We assessed the number of previously known and newly identified patients with anaemia, diabetes mellitus, thyroid dysfunction, atrial fibrillation, and hypertension in a population based sample of 85 year old people

Nonparametric Incidence Estimation From Prevalent Cohort Survival Data

Incidence is an important epidemiologic concept particularly useful in assessing an intervention, quantifying disease risk, and planning health resources. Incident cohort studies constitute the gold-standard in estimating disease incidence. However, due to material constraints, data are often collected from prevalent cohort studies whereby diseased individuals are recruited through a cross-sectional survey and followed forward in time. We discuss the identifiability of measures of incidence in the context of prevalent cohort survival studies and derive nonparametric maximum likelihood estimators and their asymptotic properties. The proposed methodology accounts for calendar-time and age-at-onset variation in disease incidence while also addressing common complications arising from the sampling scheme, hence providing flexible and robust estimates. We also discuss age-specific incidence and adjustments for temporal variations in survival. We apply our methodology to data from the Canadian Study of Health and Aging and provide insight into temporal trends in the incidence of dementia in the Canadian elderly population

Prevalence and outcomes of delirium in community and non-acute care settings in people without dementia: a report from the Canadian Study of Health and Aging

BACKGROUND: While delirium is common among older adults in acute care hospitals, its prevalence in other settings has been less well studied. We examined delirium prevalence and outcomes in a large cohort of older Canadians living outside of acute care. METHODS: In this secondary analysis of the Canadian Study of Health and Aging, the prevalence of clinically diagnosed delirium was estimated and five-year survival was compared with that of individuals with dementia of graded severity. RESULTS: Delirium was very uncommon (prevalence <0.5%) and was associated with reduced survival, similar to that of moderate-to-severe dementia. CONCLUSION: In this cohort of older Canadians, delirium in non-demented people was associated with very low 5-year survival, at levels comparable with advanced dementia. Although it is common in hospital, delirium is uncommon among older adults in their usual place of residence, suggesting that it is a potent stimulus to seek medical care

Rates of influenza vaccination in older adults and factors associated with vaccine use: A secondary analysis of the Canadian Study of Health and Aging

BACKGROUND: Influenza vaccination has been shown to reduce morbidity and mortality in the older adult population. In Canada, vaccination rates remain suboptimal. We identified factors predictive of influenza vaccination, in order to determine which segments of the older adult population might be targeted to increase coverage in influenza vaccination programs. METHODS: The Canadian Study of Health and Aging (CSHA) is a population-based national cohort study of 10263 older adults (≥ 65) conducted in 1991. We used data from the 5007 community-dwelling participants in the CSHA without dementia for whom self-reported influenza vaccination status is known. RESULTS: Of 5007 respondents, 2763 (55.2%) reported having received an influenza vaccination within the previous 2 years. The largest predictive factors for flu vaccination included: being married (57.4 vs. 52.6%, p = 0.0007), having attained a higher education (11.0 vs. 10.3 years, p < 0.0001), smoking (57.1% vs. 52.9%, p = 0.0032), more alcohol use (57.9% of those who drank more vs. 53.2% of those who drank less, p = 0.001), poorer self-rated health (54.1% of those with good self-rated health vs. 60.6% of those with poor self-rated health, p = 0.0006), regular exercise (56.8% vs. 52.0%, p = 0.001), and urban living (55.8% vs. 51.0%, p = 0.03). While many other differences were statistically significant, most were small (e.g. mean age 75.1 vs. 74.6 years for immunized vs. unimmunized older adults, p = 0.006, higher Modified Mini Mental Status Examination score (89.9 vs. 89.1, p < 0.0001), higher comorbidity (2.7 vs. 2.3 comorbidities, p < 0.0001). Residents of Ontario were more likely (64.6%) to report vaccination (p < 0.0001), while those living in Quebec were less likely to do so (48.2%, p < 0.0001). Factors retaining significance in a multivariate analysis included older age, higher education, married status, drinking alcohol, smoking, engaging in regular exercise, and having higher comorbidity. CONCLUSIONS: The vaccination rate in this sample, in whom influenza vaccination is indicated, was low (55.2%). Even in a publicly administered health care setting, influenza vaccination did not reach an important proportion of the elderly population. Whether these differences reflect patient preference or access remains to be determined