Life expectancy with cognitive impairment in the older population of the United States.
OBJECTIVE
This article provides estimates of the prevalence of cognitive impairment by age and sex for a nationally representative sample of the U.S. population aged 70 and over. From these estimates, years of life with and without cognitive impairment are calculated.


METHODS
Using data from the Assets and Health Dynamics of the Oldest Old (AHEAD) survey, the prevalence of cognitive impairment is estimated for a sample representing both the community-dwelling and institutionalized older American population. Sullivan's method is used to calculate the average number of years an elderly person can expect to live with and without cognitive impairment.


RESULTS
The prevalence of moderate to severe cognitive impairment in the total U.S. population aged 70 and over is 9.5%. At age 70, the average American can expect 1.5 years with cognitive impairment. Expected length of life with cognitive impairment is longer for women than men because of their longer life expectancy.


CONCLUSIONS
As total life expectancy continues to increase, the length of life with cognitive impairment for the American population will increase unless age-specific prevalence is reduced. There is great potential for improvement in future early treatment and diagnosis of this condition.
Suthers
Kristen
K
University of Southern California, Andrus Gerontology Center, Los Angeles, California 90089-0191, USA.
Kim
Jung Ki
JK
Crimmins
Eileen
E
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000401:mortality*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011336:Probability; D011594:Psychometrics; D012737:Sex Factors; D016019:Survival Analysis; D014481:United States