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 108H EALT H 26 The Aging, Demographics, and Memory Study (ADAMS), a supplement to the HRS, is the largest national study of the prevalence of dementia in the United States. This supplemental study has three goals: first, to establish national estimates of the prevalence of dementia and cogni- tive impairment without dementia; second, to increase understanding of the natural history of preclinical and clinical dementia, as well as the role of dementia in changing the health and social functioning of older Americans; and third, to use the data collected to assess the validity of HRS cognitive functioning measures as screening tools for cognitive impairment or dementia. The ADAMS also will provide an opportunity to conduct in-depth investigations related to the impact of dementia on formal health care utilization, informal caregiving, and total societal costs for dementia care. The study is the first of its kind to conduct in-home assessments of dementia on a national scale that represents the U.S. elderly popula- tion. The assessments are being conducted through a collaboration with Duke University. From August 2001 through March 2005, selected HRS participants were visited by a clinical research nurse and psychometric technician, both of whom were specially trained in the evaluation of dementia. Conducted in the presence of a family member, friend, or paid helper, the assessments included obtaining clinical and medical histories, neuropsychological testing, and collecting DNA samples to de- termine the apolipoprotein E (APOE) genotype. Follow-up assessments have so far been conducted with approximately 30 percent of respon- dents to gather additional data to clarify trajectories. Additional follow- ups are planned for future years. Information about caregiving and its costs and health services utilization was also collected. The primary ADAMS dataset consists of 850 respondents from the HRS for whom assessments are completed. The ADAMS data, with restric- tions on accessibility and use to protect the confidentiality of partici- pants, were made available for research purposes in early 2007. The Aging, Demographics, and Memory Study limitation (Figure 1-4). After age 80, however, the prevalence rate rises steeply, approaching 20 percent for people age 85 and older. The HRS also provides valuable information about the need for and provision of caregiving for older people with cognitive impairment. Estimates from the baseline AHEAD survey in 1993 indicated that people with mild impairment received 8.5 more hours of care per week, while those with severe impairment received 41.5 more hours of care per week than their peers with normal cogni- tive function (Langa et al. 2001). The same study found that valuing this family-provided care at the average hourly wage of a paid home aide, this informal care amounts to $17,700 per year for an individual with severe impairment, and a total national cost of $18 billion per year for informal care for all forms of cognitive impairment. Recent studies suggesting a decline in overall rates of disability among the older U.S. population have prompted researchers to consider the utility of the HRS in measuring trends in cognitive impairment over time. Analyses of HRS data from the 1990s showed a significant decline in the prevalence of severe cognitive impairment among people age 70 and older, from about 6 percent in 1993 to less than 4 percent in 1998 (Freedman et al. 2001, 2002). In contrast, another analysis of the same cohort using additional controls found very little change from 1993 to 2000 in cognitive impair- ment rates, after adjustment for demographic composition (gender, race, and ethnicity) (Rodgers et al. 2003). Scientists concentrating on the cogni- tive health aspects of participants in the HRS will continue to examine these contradictory findings in an effort to sort out the national trends. Depressive Symptoms and Depression Mental health, while critically important to the health of the population, is extremely difficult to assess in population surveys. The HRS develop- ers decided at the outset to focus on depression, the most prevalent mental health condition in the older population and a leading cause of disability. At baseline, respondents are given a series of questions to identify major depressive episodes in the prior year. In each wave of the study, respondents are asked about eight common symptoms of depression, taken from the CES-D instrument. In validation studies against the full CES-D battery, the presence of four out of the eight symptoms is associated with clinically significant depression.