Prevalence and incidence of clinically diagnosed Alzheimer's disease dementia from 1994 to 2012 in a population study

The trends in prevalence and incidence of Alzheimer's disease (AD) dementia remain uncertain.

A sample of 2794 participants with a clinical diagnosis for AD dementia were included.

The 2010 census standardized prevalence of AD dementia was 14.5% (95% CI = 13.7–15.3), and annual incidence was 2.3% (1.7–2.9). Both prevalence and incidence showed substantial variation over time, but no secular trends. The prevalence of AD dementia did not change significantly from 14.6% (95% CI = 13.0, 16.2) in 1994–1997 to 14.7% (95% CI = 13.2, 16.2) in 2010–2012 (P = .84). The annual incidence of AD dementia was 2.8% (95% CI = 2.2, 3.2) in 1998–2000 and 2.2% (95% CI = 1.6, 2.8) in 2004–2006 (P = .20) and remained steady in 2010–2012. The prevalence and incidence among African Americans were approximately twice than those among European Americans.

The prevalence and incidence of AD dementia showed substantial variation between 1994 and 2012, but no secular trend.