Table 1.
Study Population Characteristics
| Characteristics | Total Sample (n = 7,093) | Probable and Possible AD (n = 2,337) | MCI (n = 1,418) | Control (n = 3,088) |
| Sex, n (%) | ||||
| Male | 3622 (51.1) | 1,414 (60.5) | 778 (55.0) | 1,289 (41.7) |
| Female | 3471 (48.9) | 923 (39.5) | 640 (45.1) | 1,799 (58.3) |
| Age | ||||
| Mean (SD) | 74.0 (10.1) | 74.7 (10.1) | 75.1 (9.3) | 73.2 (10.3) |
| Range | 25–118 | 26–118 | 36–107 | 25–101 |
| Education | ||||
| Mean (SD) | 17.5 (1.6) | 17.4 (1.6) | 17.5 (1.6) | 17.5 (1.5) |
| Range | 16–29 | 16–27 | 16–29 | 16–29 |
| MMSE | ||||
| Mean (SD) | 28.4 (14.4) | 23.8 (17.9) | 29.0 (10.4) | 30 (12.2) |
| Range | 0–30 | 0–30 | 0–30 | 21–30 |
| Race | ||||
| Caucasian | 6,296 (88.8) | 2,111 (90.3) | 1,257 (88.6) | 2,713 (87.9) |
| African American | 581 (8.2) | 149 (6.4) | 115 (8.1) | 294 (9.5) |
| AI or AN | 4 (0.1) | 1 (<0.1) | 0 | 3 (0.1) |
| NH or PI | 2 (<0.1) | 1 (<0.1) | 0 | 1 (<0.1) |
| Asian | 149 (2.1) | 48 (2.1) | 36 (2.5) | 59 (1.9) |
| Other | 43 (0.6) | 22 (1.0) | 7 (0.5) | 11 (0.4) |
| Language | ||||
| English | 6,764 (95.4) | 2,244 (96.0) | 1,349 (95.1) | 2,940 (95.2) |
| Spanish | 116 (1.6) | 42 (2.0) | 22 (1.6) | 43 (1.4) |
| Mandarin | 25 (0.4) | 5 (0.2) | 7 (0.5) | 10 (0.3) |
| Cantonese | 5 (0.1) | 2 (0.1) | 2 (0.1) | 1 (<0.1) |
| Russian | 10 (0.1) | 2 (0.1) | 4 (0.3) | 3 (0.1) |
| Japanese | 3 (<0.1) | 1 (<0.1) | 1 (0.1) | 1 (<0.1) |
| Other | 104 (1.5) | 34 (1.5) | 28 (2.0) | 37 (1.2) |
| Unknown | 66 (0.9) | 7 (0.3) | 22 (1.6) | 53 (1.7) |
Note : AD = Alzheimer's disease; AI = American Indian; AN = Alaska Native; MCI = mild cognitive impairment; MMSE = Mini-Mental State Examination; NH = Native Hawaiian; and PI = Pacific Islander.