b'AGING IN THE 21ST CENTURYFIGURE 2-2Prevalence of dementia, AD and VaD by gender: 2002 The prevalence of dementia in those aged Source: Plassman et al. (2007). 71 and older was 13.7%, corresponding to ap-proximately 3.4 million individuals in 2002. AD 45% prevalence was 9.7%, or 2.4 million nationally. 40% AD increases as the leading cause of dementia 35% with age, accounting for 79.5% of all dementia among those aged 90 and older. Figure 2-2 shows 30% the prevalence of dementia is comparable for men 25% and women in the youngest age group but higher 20% among women aged 80 to 89. Interestingly, in the 15% oldest age group (90 and older), the prevalence of 10% dementia is higher for men. These patterns are similar for both AD and VaD.5%Another study reports on the prevalence of 0% Male Female Male Female Male Female CIND. This form of cognitive impairment was All dementia AD VaD 22.2% in 2002, which was about 70% higher than the estimated prevalence of AD (Plassman et al. People aged: 71-79 80-89 902008). CIND was further categorized as prodro-mal AD (a form of early AD), vascular cognitive FIGURE 2-3Prevalence of CIND subtype by age: 2002 impairment without dementia and stroke, and Source: Plassman et al. (2008). impairment arising from other medical condi-tions. Figure 2-3 shows the prevalence of each of 40% these CIND subtypes by age group. Even in the youngest group, 71- to 79-year-olds, about one 35% in seven individuals has some type of cognitive 30% impairment. With follow-up every two years through 25% 2009, ADAMS data could be used to determine 20% the number of new cases of dementia and CIND (Plassman et al. 2011). Figure 2-4 shows the 15%incidence of dementia was 33.3 cases per 1,000, 10% while AD was 22.9 cases per 1,000. Extrapolating 5% from the study sample to the US population, the overall number of new cases of dementia during 0% Cognitive impairment Prodromal Alzheimers Vascular cognitive Medical conditions the study period is estimated to be 3.4 million, without dementia (n=241) disease (n=98) impairment without (n=55) which included approximately 2.3 million new dementia and cases of AD. There were an additional 4.8 million Age: 71-79 80-89 90 stroke (n=54)new cases of CIND. Incidence Type| Age Group, yr| Estimate of Incidence/1,00 Person-Years (SE) |Estimate of Population Incident Cases40'