Prevalence of cognitive impairment without dementia in the United States
Langa, Kenneth M., Steven Heeringa, David Weir, Mary Beth Ofstedal, Willard L. Rodgers, Robert Willis, B.L. Plassman, G.G. Fisher, et al. 2008. "Prevalence of cognitive impairment without dementia in the United States." Annals of Internal Medicine, 148(6): 427-434.
Cognitive impairment without dementia is associated with increased risk for disability, increased health care costs, and progression to dementia. This study estimates the prevalence of cognitive impairment without dementia in the United States and determines longitudinal cognitive and mortality outcomes. Estimates are derived from participants in the ADAMS (Aging, Demographics, and Memory Study) who were age 71 years or older drawn from the nationally representative HRS (Health and Retirement Study). Assessments included neuropsychological testing, neurologic examination, and clinical and medical history. National prevalence rates were estimated by using a population-weighted sample. Results: In 2002, an estimated 5.4 million people (22.2%) in the United States age 71 years or older had cognitive impairment without dementia. Prominent subtypes included prodromal Alzheimer disease (8.2%) and cerebrovascular disease (5.7%). Among participants who completed follow-up assessments, 11.7% with cognitive impairment without dementia progressed to dementia annually, whereas those with subtypes of prodromal Alzheimer disease and stroke progressed at annual rates of 17% to 20%.
PMCID: PMC2670458. (Pub Med Central)