Deborah Barnes, PhD
June 10, 2007
Simple Test Predicts Six-Year Risk of Dementia
The test, developed in the study by the researchers,
is a 14-point index combining medical history, cognitive testing, and
physical examination. It requires no special equipment and can be given
in a clinical setting such as a doctor’s office or at a patient’s
The new index is the “bedside”
version of a longer, more technically comprehensive “best” test, also
developed during the study, that is 88 percent accurate.
are the first tools to accurately predict dementia, according to lead
author Deborah E. Barnes, PhD, a mental health researcher at SFVAMC.
Barnes described the tests in a presentation at the 2007 International
Conference on Prevention of Dementia, in Washington, DC, sponsored by
the Alzheimer’s Association.
tests that accurately predict an individual’s chances of developing
cardiovascular disease and other maladies, but, until now, no one has
developed similar scales for dementia,” says Barnes, who also is an
assistant professor of psychiatry at the University of California, San
As measured by the
“bedside” index, the risk factors for developing dementia are an age of
70 or older, poor scores on two simple cognitive tests, slow physical
functioning on everyday tasks such as buttoning a shirt or walking 15
feet, a history of coronary artery bypass surgery, a body mass index of
less than 18, and current non-consumption of alcohol.
who score 0 to 3 on the “bedside” test have a 6 percent chance of
developing dementia within six years. A score of 4 to 6 indicates a 25
percent chance. People with a score of 7 or higher have a 54 percent
chance of developing dementia within six years.
18-point comprehensive, or “best,” test measures for all “bedside” risk
factors plus factors that would be more difficult to measure as part of
a routine clinical visit. These include brain magnetic resonance
imaging (MRI) findings of enlarged ventricles –– the fluid-filled
cavities between brain tissue -- or diseased white matter –– the nerve
cells that transmit signals between grey matter; thickening of the
internal carotid artery, which brings blood to the head and neck; and
the presence of one or two copies of the e4 allele, or subtype, of
APO-E, the gene that codes for the protein known as Apolipoprotein. The
presence of APO-E e4 alleles is a known risk factor for Alzheimer’s
A “best” test score of 0 to 4
indicates a 4 percent chance of developing dementia within six years. A
score of 5 to 8 indicates a 25 percent chance. A score of 9 or higher
indicates a 52 percent chance of developing dementia within six years.
develop the tests, the study authors tracked a broad range of physical,
mental, demographic and other variables for six years among 3,375
participants in the Cardiovascular Health Cognition Study, a national
prospective study sponsored by the National Heart, Lung, and Blood
At the beginning of
the study, none of the subjects were demented. Their mean age was 76.
Fifty-nine percent were women and 15 percent were African-American. By
the end of the study, 14 percent of the subjects had developed
dementia. The variables that were predictive of dementia in a
statistically significant way became the basis of the tests.
authors caution that there were no Hispanics or Asian-Americans
included in the study population, and that the new scales need
validation in other study groups before they can become standard
“We certainly plan to
look at other groups to see if these results are valid across a variety
of populations,” says Barnes. Co-authors of the study are Kenneth E.
Covinsky, MD, MPH, of SFVAMC and UCSF; Lewis H. Kuller, MD, DrPH, and
Oscar L. Lopez, MD, of the University of Pittsburgh, Pittsburgh, Penn.;
and Kristine Yaffe, MD, of SFVAMC and UCSF.
The research was funded by a grant from the National Institute on Aging.
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