Which age group had approximately 4% prevalence of Alzheimer's disease in 2013?

The age group that had approximately 4% prevalence of Alzheimer's disease in 2013 is people under age 65. This figure aligns with the statistical understanding that Alzheimer's disease primarily affects older adults, but there are cases of early-onset Alzheimer's, which can occur in individuals younger than 65, making it relatively small in prevalence when measured across the entire age group.

In the context of Alzheimer’s disease statistics, commonly, the prevalence is significantly lower in younger age groups, particularly in those under 18 or within the 18 to 34 age brackets, as these populations are less likely to develop the condition. The prevalence among people under 65 incorporates those in the 35 to 64 age range who may have early-onset Alzheimer's but is still relatively low compared to older populations, reinforcing why this figure is around 4%. The statistical trends indicate that as age increases, the incidence and prevalence of Alzheimer's disease rise sharply, but the data we have from 2013 indicates a modest prevalence in adults under 65.