Kathleen S. Hall

Global prevalence of dementia: a Delphi consensus study.

BACKGROUND 100 years after the first description, Alzheimers disease is one of the most disabling and burdensome health conditions worldwide. We used the Delphi consensus method to determine dementia prevalence for each world region. METHODS 12 international experts were provided with a systematic review of published studies on dementia and were asked to provide prevalence estimates for every WHO world region, for men and women combined, in 5-year age bands from 60 to 84 years, and for those aged 85 years and older. UN population estimates and projections were used to estimate numbers of people with dementia in 2001, 2020, and 2040. We estimated incidence rates from prevalence, remission, and mortality. FINDINGS Evidence from well-planned, representative epidemiological surveys is scarce in many regions. We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year (one new case every 7 seconds). The number of people affected will double every 20 years to 81.1 million by 2040. Most people with dementia live in developing countries (60% in 2001, rising to 71% by 2040). Rates of increase are not uniform; numbers in developed countries are forecast to increase by 100% between 2001 and 2040, but by more than 300% in India, China, and their south Asian and western Pacific neighbours. INTERPRETATION We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.

Alzheimer's disease and vascular dementia in developing countries: prevalence, management, and risk factors

Despite mortality due to communicable diseases, poverty, and human conflicts, dementia incidence is destined to increase in the developing world in tandem with the ageing population. Current data from developing countries suggest that age-adjusted dementia prevalence estimates in 65 year olds are high (>or=5%) in certain Asian and Latin American countries, but consistently low (1-3%) in India and sub-Saharan Africa; Alzheimers disease accounts for 60% whereas vascular dementia accounts for approximately 30% of the prevalence. Early-onset familial forms of dementia with single-gene defects occur in Latin America, Asia, and Africa. Illiteracy remains a risk factor for dementia. The APOE epsilon4 allele does not influence dementia progression in sub-Saharan Africans. Vascular factors, such as hypertension and type 2 diabetes, are likely to increase the burden of dementia. Use of traditional diets and medicinal plant extracts might aid prevention and treatment. Dementia costs in developing countries are estimated to be US

Prevalence of cognitive impairment Data from the Indianapolis Study of Health and Aging

73 billion yearly, but care demands social protection, which seems scarce in these regions.

Trends in the incidence and prevalence of Alzheimer’s disease, dementia, and cognitive impairment in the United States

Background: The epidemiology and natural history of cognitive impairment that is not dementia is important to the understanding of normal aging and dementia. Objective: To determine the prevalence and outcome of cognitive impairment that is not dementia in an elderly African American population. Method: A two-phase, longitudinal study of aging and dementia. A total of 2212 community-dwelling African American residents of Indianapolis, IN, aged 65 and older were screened, and a subset (n = 351) received full clinical assessment and diagnosis. Subsets of the clinically assessed were seen again for clinical assessment and rediagnosis at 18 and 48 months. Weighted logistic regression was used to generate age-specific prevalence estimates. Results: The overall rate of cognitive impairment among community-dwelling elderly was 23.4%. Age-specific rates indicate increasing prevalence with increasing age: 19.2% for ages 65 to 74 years, 27.6% for ages 75 to 84 years, and 38.0% for ages 85+ years. The most frequent cause of cognitive impairment was medically unexplained memory loss with a community prevalence of 12.5%, followed by medical illness–associated cognitive impairment (4.0% prevalence), stroke (3.6% prevalence), and alcohol abuse (1.5% prevalence). At 18-month follow-up, 26% (17/66) of the subjects had become demented. Conclusions: Cognitive impairment short of dementia affects nearly one in four community-dwelling elders and is a major risk factor for later development of dementia.

Serum cholesterol, APOE genotype, and the risk of Alzheimer's disease : A population-based study of African Americans

Declines in heart disease and stroke mortality rates are conventionally attributed to reductions in cigarette smoking, recognition and treatment of hypertension and diabetes, effective medications to improve serum lipid levels and to reduce clot formation, and general lifestyle improvements. Recent evidence implicates these and other cerebrovascular factors in the development of a substantial proportion of dementia cases. Analyses were undertaken to determine whether corresponding declines in age‐specific prevalence and incidence rates for dementia and cognitive impairment have occurred in recent years. Data spanning 1 or 2 decades were examined from community‐based epidemiological studies in Minnesota, Illinois, and Indiana, and from the Health and Retirement Study, which is a national survey. Although some decline was observed in the Minnesota cohort, no statistically significant trends were apparent in the community studies. A significant reduction in cognitive impairment measured by neuropsychological testing was identified in the national survey. Cautious optimism appears justified.

Community screening interview for dementia (CSI 'D'); performance in five disparate study sites.

Article abstract A significant interaction among total serum cholesterol (TC), APOE genotype, and AD risk was found in a population-based study of elderly African Americans. Increasing TC was associated with increased AD risk in the group with no ε4 alleles, whereas TC was not associated with increased AD risk in the group with one or more ε4 alleles. Further study of the relationship between cholesterol and APOE genotype is needed to confirm this association, but the results suggest that cholesterol may be a potentially modifiable environmental risk factor for AD.

The Relationship Between Alcohol Consumption, Cognitive Performance, and Daily Functioning in an Urban Sample of Older Black Americans

The Community Screening Interview for Dementia (CSI ‘D’) was developed as a screening instrument for dementia for use in cross‐cultural studies. It consists of two components, a cognitive test for non‐literate and literate populations and an informant interview regarding performance in everyday living. The development of the CSI ‘D’, involving harmonization, translation, back translation and pilot testing, for use in five sites is described. The results demonstrate the adaptability and utility of the CSI ‘D’ in populations from very different socioeconomic backgrounds. The inclusion of informant data adds significantly to the performance of the CSI ‘D’ as a dementia screen. The combination of informant and cognitive scores in a discriminant score produces better sensitivity and specificity for dementia than cognitive scores alone. The informant score has a significant independent effect in predicting dementia. Copyright

Low education and childhood rural residence Risk for Alzheimer’s disease in African Americans

OBJECTIVE: To report on moderate alcohol consumption and measurements of cognitive function and activities of daily living in an older, urban, community‐dwelling sample of black Americans.

Effects of age, education, and gender on CERAD neuropsychological test performance in an African American sample

Objective: To examine the relationship between level of education and childhood rural residence as possible risk factors for AD in African Americans in Indianapolis. Background: Low level of education has been a risk factor for AD in some studies, but childhood rural residence has not been addressed in most of these studies. Methods: A two-stage community-based prevalence study of AD was conducted in a random sample of 2,212 African Americans ≥65 years of age. A subsample of clinically assessed normal individuals (180) and individuals diagnosed with AD (43) were compared on the variables of rural/urban residence in childhood and low (≤6 years) or high (≥7 years) education. A logistic regression model was used with interaction between rural residence and low education to estimate odds ratios for the two risk factors combined, adjusting for age and gender. Results: Odds ratios for AD: 6.5 (95% CI: 2.6 to 16.7) low education/rural residence; 0.5 (95% CI: 0.1 to 2.9) low education/urban residence; 1.5 (95% CI: 0.4 to 5.2) high education/rural residence, comparing with the group of high education/urban residence. Conclusion: Childhood rural residence, combined with ≤6 years of school, was associated with an increased risk of AD in this sample. It is possible that low education by itself is not a major risk factor for AD, but, rather, is a marker for other accompanying deleterious socioeconomic or environmental influences in childhood.

Late Life Leisure Activities and Risk of Cognitive Decline

Abstract Eighty-three normal, healthy, African American men and women aged 65 and older completed the Consortium to Establish a Registry for Alzheimers Disease-Neuropsychological Battery (CERAD-NB). Regression analyses indicated powerful education and less marked age and gender influences on CERAD-NB test performance. Higher education was associated with better performance on nearly all CERAD-NB tests, age effects were noted only on the memory indices (younger subjects had better scores), and women performed slightly better than men on one index from the Word List Learning Test. Age and education interacted on the Word List Learning Test such that the best scores were obtained by younger subjects with more years of schooling; the other age-education combinations did not differ from each other. Factor analysis revealed a two-factor solution (i.e., a nonmemory general cognitive factor and a verbal memory factor) which accounted for 67% of the variance. Education-stratified normative data are presented for ...