Table 1.
Demographics
| Affected sibs (n = 214) |
Unaffected sibs (n = 234) |
|
|---|---|---|
| Age at MRI1 | 75.0 (9.1) | 71.6 (9.0) |
| No. (%) | No. (%) | |
| Highest Level of Education2 | ||
| Less than 6th grade | 20 (9) | 12 (5) |
| 7th through 12th grade | 100 (47) | 102 (44) |
| College | 64 (30) | 85 (36) |
| Graduate or professional | 27 (13) | 34 (15) |
| Ethnicity3 | ||
| Caucasian non-Hispanic | 120 (56) | 137 (59) |
| Caucasian Hispanic | 32 (15) | 30 (13) |
| African American | 36 (17) | 35 (15) |
| Japanese American | 23 (11) | 31 (13) |
| APOE4 | ||
| 44, 24 | 42 (20) | 22 (9) |
| 34, 23 | 103 (48) | 96 (41) |
| 33 | 62 (29) | 106 (45) |
1
Pooled t-test P < .0001.
2
Two-sided Wilcoxon test P = .066.
3
Two-sided Wilcoxon test P = .60.
4
χ2test P < .0001.