Table 1.
Characteristics of the Sample
| Overall sample | ε4 carriers | ε4 noncarriers | p valuea | |
|---|---|---|---|---|
| N | 487 | 100 | 387 | — |
| Demographic | ||||
| Age (years) | 82.5 (7.50) | 81.7 (7.86) | 82.7 (7.40) | .216 |
| Female (%) | 76.6 | 78.0 | 76.2 | .709 |
| Education (years) | 15.2 (3.04) | 15.8 (3.11) | 15.1 (3.01) | .026 |
| Non-Hispanic White (%) | 90.6 | 91.0 | 90.4 | .864 |
| Cognitionb | ||||
| Global cognition | 0.251 (0.524) | 0.211 (0.548) | 0.261 (0.518) | .397 |
| Episodic memory | 0.380 (0.689) | 0.305 (0.698) | 0.400 (0.686) | .221 |
| Semantic memory | 0.259 (0.595) | 0.222 (0.620) | 0.269 (0.589) | .491 |
| Working memory | 0.148 (0.726) | 0.209 (0.785) | 0.132 (0.710) | .351 |
| Perceptual speed | 0.113 (0.805) | 0.056 (0.745) | 0.129 (0.820) | .426 |
| Visuospatial abilities | 0.223 (0.718) | 0.170 (0.743) | 0.237 (0.712) | .408 |
| Literacy | ||||
| Total literacy (% correct) | 67.3 (14.5) | 65.2 (14.8) | 67.8 (14.4) | .105 |
| Health literacy (% correct) | 61.9 (18.5) | 58.4 (18.5) | 62.7 (18.5) | .039 |
| Financial literacy (% correct) | 72.7 (15.9) | 71.8 (16.3) | 73.0 (15.7) | .519 |
Notes. Values are mean (SD) unless otherwise noted.
aStatistical significance comparing ε4 carriers versus noncarriers based on t tests or χ2.
bValues for cognitive measures represent z scores standardized using the baseline mean and SD of the entire Rush Memory and Aging Project cohort, of which the current sample is a subset.