Table 1.
Sample demographics
| Variable | Normal | MCI | Dementia | Contrasts/Chi-square | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | M (or %) | SD (range) | n | M (or %) | SD (range) | n | M (or %) | SD (range) | ||
| Age | 10,165 | 70.53 | 10.49 (18–101) | 3973 | 72.94 | 9.35 (22–106) | 4,272 | 71.75 | 10.48 (24–103) | A < C < B |
| Education | 10,115 | 16.11 | 2.86 (0–29) | 3944 | 15.86 | 3.04 (0–26) | 4,233 | 15.39 | 3.21 (0–30) | C < B < A |
| Sex: male | 3593 | 35.3% | 2016 | 50.7% | 2,199 | 51.5% | χ2, p < .001 | |||
| Race | χ2, p < .001 | |||||||||
| White | 7943 | 78.1% | 3166 | 79.7% | 3,721 | 87.1% | ||||
| Black | 1652 | 16.3% | 596 | 15.0% | 327 | 7.7% | ||||
| Am. Indian or Alaska Native | 91 | 0.9% | 29 | 0.7% | 28 | 0.7% | ||||
| Native Hawaiian or Pac. Islander | 13 | 0.1% | 5 | 0.1% | 6 | 0.1% | ||||
| Asian | 315 | 3.1% | 112 | 2.8% | 110 | 2.6% | ||||
| Other | 81 | 0.8% | 31 | 0.8% | 38 | 0.9% | ||||
| Unknown | 70 | 0.7% | 34 | 0.9% | 42 | 1.0% | ||||
| Hispanic | χ2, p < .001 | |||||||||
| No | 9413 | 92.6% | 3615 | 91.0% | 4,012 | 93.9% | ||||
| Yes | 703 | 6.9% | 344 | 8.7% | 245 | 5.7% | ||||
| Unknown | 49 | 0.5% | 14 | 0.4% | 15 | 0.4% | ||||
| Handedness | χ2, p = .001 | |||||||||
| Left | 840 | 8.3% | 396 | 10.0% | 408 | 9.6% | ||||
| Right | 9089 | 89.8% | 3462 | 87.8% | 3,773 | 88.8% | ||||
| Ambidextrous | 196 | 1.9% | 86 | 2.2% | 66 | 1.6% | ||||
Note: Contrasts performed using the Tukey HSD method and all relationships shown were significant at the p < .001 level.