Dementia in 90+ population expected to become epidemic
University of California researchers found that the incidence rate for all causes of dementia in people age 90 and older is 18.2% annually, and significantly increases with age in both men and women.
This research, called “The 90+ Study” is one of only a few to examine dementia in this age group, and the first to have sufficient participation of centenarians.
Findings of the study appear in the February issue of Annals of Neurology, a journal published by Wiley-Blackwell on behalf of the American Neurological Association.
Dr Maria Corrada explained that the population-based, longitudinal study of ageing and dementia showed that dementia incidence rates almost double every five years in those 90 and older.
Researchers found the overall incidence rate based on 770 person-years of follow-up was 18.2% per year. Rates increased with age from 12.7% per year in the 90-94 age group, to 21.2% per year in the 95-99 age group, to 40.7% per year in the 100+ age group.
Incidence rates were very similar for men and women. Previous results from The 90+ Study found higher estimates of dementia prevalence in women (45%) compared to men (28%), a result also seen in other similar studies.
“In contrast to other studies, we found that the incidence of dementia increases exponentially with age in both men and women past age 90,” said Dr Corrada.
“Given the population projections for this age group along with our findings, dementia in the oldest-old threatens to become an epidemic with enormous public health impact.”
