This late-life index is slightly more accurate than the midlife index, which "may suggest that it is easier to predict dementia risk closer to symptom onset," the researchers said, "or it may be a function of the relatively simple measures used in the midlife index."
A major challenge for the study of dementia, Khachaturian said, is the inability to detect the disease in the early stages, before a patient has any symptoms. A tool like the one developed by Barnes and her colleagues could potentially solve this problem.
But Dr. Steven DeKosky, dean of the University of Virginia's School of Medicine, suggested that the tool would be most helpful once effective preventive medications are developed.
"Then it will be very useful to have simple, non-invasive ways of identifying people at greater or lesser risk of developing the disease," he said.
Dr. Samuel Gandy of the Mount Sinai School of Medicine in New York, noted, however, that "nothing currently available offers meaningful sustained slowing of progression" -- in other words, even if patients knew to expect Alzheimer's there would be little to nothing they could do about it.
Still, if the index is proven in other studies to be effective, Barnes said, it could prove helpful in a clinical setting by identifying "people who have no signs of dementia but should be monitored closely, allowing them to begin treatment as soon as possible, and potentially helping them maintain their thinking and memory skills and quality of life longer."
This article was developed in collaboration with ABC News.
The study was supported by grants from the National Heart, Lung, and Blood Institute and the National Institute on Aging. Additional support was provided by the National Institute of Neurological Disorders and Stroke and an NIH/National Center for Research Resources UCSF-CTSI grant. Barnes receives funding through a Career Development Award from the NIH.
The study authors reported no financial disclosures.
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