Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 76 Page 77 Page 78 Page 79 Page 80 Page 81 Page 82 Page 83 Page 84 Page 85 Page 86 Page 87 Page 88 Page 89 Page 90 Page 91 Page 92 Page 93 Page 94 Page 95 Page 96 Page 97 Page 98 Page 99 Page 100 Page 101 Page 102 Page 103 Page 104 Page 105 Page 106 Page 107 Page 108AGING IN THE 21S T CENTURY 40 The prevalence of dementia in those aged 71 and older was 13.7%, corresponding to ap- proximately 3.4 million individuals in 2002. AD prevalence was 9.7%, or 2.4 million nationally. AD increases as the leading cause of dementia with age, accounting for 79.5% of all dementia among those aged 90 and older. Figure 2-2 shows the prevalence of dementia is comparable for men and women in the youngest age group but higher among women aged 80 to 89. Interestingly, in the oldest age group (90 and older), the prevalence of dementia is higher for men. These patterns are similar for both AD and VaD. Another study reports on the prevalence of CIND. This form of cognitive impairment was 22.2% in 2002, which was about 70% higher than the estimated prevalence of AD (Plassman et al. 2008). CIND was further categorized as prodro- mal AD (a form of early AD), vascular cognitive impairment without dementia and stroke, and impairment arising from other medical condi- tions. Figure 2-3 shows the prevalence of each of these CIND subtypes by age group. Even in the youngest group, 71- to 79-year-olds, about one in seven individuals has some type of cognitive impairment. With follow-up every two years through 2009, ADAMS data could be used to determine the number of new cases of dementia and CIND (Plassman et al. 2011). Figure 2-4 shows the incidence of dementia was 33.3 cases per 1,000, while AD was 22.9 cases per 1,000. Extrapolating from the study sample to the US population, the overall number of new cases of dementia during the study period is estimated to be 3.4 million, which included approximately 2.3 million new cases of AD. There were an additional 4.8 million new cases of CIND. FIGURE 2-2  Prevalence of dementia, AD and VaD by gender: 2002 Source: Plassman et al. (2007). 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% Male Female Male Female Male Female All dementia AD VaD 71-79 80-89 ≥90 People aged: 71-79 80-89 ≥90 0% 5% 10% 15% 20% 25% 30% 35% 40% Cognitive impairment without dementia (n=241) Prodromal Alzheimer’s disease (n=98) Vascular cognitive impairment without dementia and stroke (n=54) Medical conditions (n=55) Age: Incidence Type | Age Group, yr | Estimate of Incidence/1,00 Person-Years (SE) | Estimate of Population Incident Cases FIGURE 2-3  Prevalence of CIND subtype by age: 2002 Source: Plassman et al. (2008).