Table 1.
Characteristics of Elderly Americans by Cognitive Status (Percentage, 95% Confidence Intervals)
| Characteristic | Normal | CIND | Dementia | P Value |
|---|---|---|---|---|
| Age, years | ||||
| 71–79 | 79.0 (74.1–83.9) | 16.0 (11.5–20.5) | 5.0 (2.6–7.3) | |
| ≥80 | 42.4 (37.2–47.5) | 31.0 (26.4–35.6) | 26.6 (21.8–31.5) | P < .001 |
| Sex | ||||
| Male | 63.5 (59.1–67.8) | 25.4 (21.8–29.0) | 11.1 (7.8–14.5) | |
| Female | 64.1 (58.4–69.7) | 20.2 (14.8–25.6) | 15.7 (12.4–19.1) | P = .766 |
| Race | ||||
| White | 66.2 (63.0–69.5) | 21.3 (17.7–24.8) | 12.5 (10.3–14.7) | |
| Non-white | 43.9 (30.6–57.2) | 30.2 (21.0–39.4) | 25.9 (14.4–37.4) | P =.001 |
| APOE-e4 | ||||
| 0 alleles | 66.4 (62.2–70.6) | 22.0 (18.5–25.5) | 11.6 (9.0–14.1) | |
| 1 or 2 alleles | 57.0 (48.1–65.8) | 22.7 (14.2–31.2) | 20.3 (14.2–26.4) | P = .026 |
| Region at birth | ||||
| Northeast US | 73.2 (63.9–82.5) | 18.7 (12.3–25.2) | 8.1 (2.9–13.3) | |
| Midwest US | 65.2 (57.8–72.5) | 22.1 (15.4–28.7) | 12.8 (8.0–17.5) | |
| South US | 57.2 (50.9–63.4) | 24.2 (17.5–30.9) | 18.6 (12.9–24.3) | |
| West US | 63.3 (50.3–76.2) | 22.3 (7.5–37.2) | 14.4 (1.5–27.3) | |
| Foreign | 60.6 (45.4–75.7) | 24.5 (13.3–35.8) | 14.9 (7.5–22.3) | P = .026 |
Note: CIND = cognitively impaired but no dementia.