Prevalence of dementia in the United States: the aging, demographics, and memory study.

AIM: To estimate the prevalence of Alzheimer's disease (AD) and other dementias in the USA using a nationally representative sample. METHODS: The Aging, Demographics, and Memory Study sample was composed of 856 individuals aged 71 years and older from the nationally representative Health and Retirement Study (HRS) who were evaluated for dementia using a comprehensive in-home assessment. An expert consensus panel used this information to assign a diagnosis of normal cognition, cognitive impairment but not demented, or dementia (and dementia subtype). Using sampling weights derived from the HRS, we estimated the national prevalence of dementia, AD and vascular dementia by age and gender. RESULTS: The prevalence of dementia among individuals aged 71 and older was 13.9%, comprising about 3.4 million individuals in the USA in 2002. The corresponding values for AD were 9.7% and 2.4 million individuals. Dementia prevalence increased with age, from 5.0% of those aged 71-79 years to 37.4% of those aged 90 and older. CONCLUSIONS: Dementia prevalence estimates from this first nationally representative population-based study of dementia in the USA to include subjects from all regions of the country can provide essential information for effective planning for the impending healthcare needs of the large and increasing number of individuals at risk for dementia as our population ages.

Asset and Health Dynamics Among the Oldest Old: an overview of the AHEAD Study.

This chapter provides background information for the study of Asset and Health Dynamics Among the Oldest Old (AHEAD), a prospective panel survey of persons born in 1923 or earlier who were residing in the community at the time of the 1993 baseline. Interviews were sought with both spouses in married households, and an overall total of 8,222 were completed. We review the interdisciplinary scientific issues that motivated the study, describe the fundamental design decisions that structured AHEAD, and summarize the content in the core and experimental modules. The study provides unusually detailed data on cognition, family structure and transfers, and assets. Data are presented on sample selections, response rates, and oversamples of minority groups. Basic descriptive data on the demographic, health, and socioeconomic attributes of respondents also are presented. Plans for future waves of AHEAD are described, including a next-of-kin interview for decreased respondents.

Medical insurance and the use of health care services by the elderly.

The objective of this paper is to find how health insurance influences the use of health care services by the elderly. On the basis of the first wave of the Asset and Health Dynamics Survey, we find that those who are the most heavily insured use the most health care services. Because our data show little relationship between observable health measures and either the propensity to hold or to purchase private insurance, we interpret this as an effect of the incentives embodied in the insurance, rather than as the result of adverse selection in the purchase of insurance.

The economic status of the elderly.

Augmented by public programs such as Social Security and Medicare, incomes of the elderly in the United States have grown more rapidly during the last several decades than have the incomes of other groups, so that on average the elderly are at least as well off as the nonelderly. Not all elderly, however, have done as well: widows, in particular, have high poverty rates. The economic prospects of the elderly during the next few decades are good because of the large work force from the baby-boom cohort. In the distant future a large fraction of the population will be elderly, which will probably lead to a deterioration in their economic status. Today, the main problems center on the distribution of economic resources among the elderly and on uncertainties such as costs of medical care.