FRIDAY, March 5 (HealthDay News) -- The incidence of dementia among people aged 90 years and above is very high, and increases exponentially with age, according to a study in the January issue of the Annals of Neurology.
María M. Corrada, of the University of California in Irvine, and colleagues conducted a study of 330 people aged 90 years and above who did not have dementia at baseline and who were followed up for four years.
The researchers found that, during the study period, 18.2 percent of participants became demented each year, with men and women having similar rates. The rates increased exponentially with age, from 12.7 percent per year in the 90 to 94 age group to 21.2 percent per year for those aged 95 to 99, and 40.7 percent per year for those aged 100 and above.
"Dementia in the oldest old threatens to become an epidemic with enormous public health impact. Projections of the number of people with dementia should account for the possibility that incidence of dementia continues to increase with age after the age of 90 years," the authors write. "The accuracy of these estimates will be crucial for adequate planning of health care resources."