Tuesday, June 12, 2007

AAICPD: Low-Tech Tool Predicts Six-Year Risk of Dementia

WASHINGTON, June 11 -- The risk of developing dementia within six years can be predicted by a simple assessment tool that relies on clinical impression and patient history, researchers reported here.
The key indicators were older age, non-white race, poor cognitive function, poor physical performance, extreme inactivity, history of bypass surgery, low body mass index, and lack of alcohol consumption (ROC, 0.79; 95% CI: 0.76 - 0.81; accuracy, 87%), said Deborah F. Barnes, Ph.D., of the University of California San Francisco.
The score based on these factors ranged from 0 to 14 points, and the risk of developing dementia was 6% in those with low scores (0-3 points), compared with 25% in those with moderate scores (4-6 points), and 54% in patients with high scores (≥7), she reported at the Alzheimer's Association International Conference on Prevention of Dementia.
Moreover, evaluation of these factors can be performed in a physician's office or at bedside in a hospital by a nurse practitioner or a physician's assistant, Dr. Barnes found.
She noted that this low-tech model was not as accurate as one that incorporates MRI and other expensive tests. By statistical analysis the high-tech model was significantly better (P<0.001), but the "absolute differences between the two was small."
"We wanted a tool that could be used quickly in a clinical setting and wouldn't require expensive or sophisticated measures, like MRI," she said in an interview. "We looked at a number of potential predictors and settled on these as a reasonable model that a clinician could use when evaluating an older adult."
On the basis of an analysis of data from 3,375 non-demented participants in the Cardiovascular Health Cognition Study, Dr. Barnes and colleagues developed the two models -- a bedside predictive protocol and the so-called best predictive model. At baseline, participants had a mean age of 76; 59% were women, and 15% were African American.
Fourteen percent (480) of those in the analysis developed dementia over six years of follow-up.
The best model included testing for apolipoprotein-E genotype, MRI findings, electrocardiogram findings, carotid artery ultrasound, and ankle-arm brachial index, as well as demographics, medical history, psychosocial measures, physical function, cognitive function, self-rated health and medication use.
Dr. Barnes said the simple protocol can be used to aid in evaluation of "elderly patients about whom the clinician may have some concerns or patients whose family members raise concerns about performance or ability to live independently."
Unlike cardiovascular disease or diabetes in which elevated risk triggers preventive measures, including pharmacologic interventions, Dr. Barnes conceded that little is known about preventing dementia, which also raises questions about the value of a predictive model.
She agreed that there are no medications that have been shown to reduce the risk of dementia, but said there are a number of compounds under development "so it may be that we will soon have drugs that can be used in patients who have an identified increased risk."
Additionally, she said that several studies have suggested lifestyle interventions, specifically both mental and physical exercise, that have been associated with a reduced risk of dementia.
"It would be reasonable to initiate both an exercise program and a program of mental drills or exercises such as word puzzles in patients who are identified as high risk for dementia," she said.
Dr. Barnes disclosed no conflicts. The study was funded by the National Institutes of Health.Primary source: Second Alzheimer's Association International Conference on Prevention of DementiaSource reference: Barnes, D et al "Predicting an individual's risk of developing dementia: the Cardiovascular Health Cognition Study" Abstract 108.

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