Table 1.
Descriptive Statistics for the Current Sample
| Control | MCI | AD | Total | |
|---|---|---|---|---|
| N | 269 | 200 | 57 | 526 |
| Age, years | 72.4 (8.5) | 72.5 (8.6) | 79.7 (7.1) | 73.2 (8.7) |
| Education, years | 16.1 (2.8) | 14.6 (3.3) | 14.6 (3.2) | 15.4 (3.1) |
| Sex, % Female | 66.9% | 59.0% | 42.1% | 61.2% |
| Ethnicity, % African-American | 15.2% | 35.5% | 15.8% | 23.0% |
| Mini Mental State Exam | 29.2 (1.3) | 28.1 (1.9) | 24.2 (3.6) | 28.2 (2.4) |
| WRAT-3 Reading Scaled Score | 111.3 (11.5) | 104.8 (13.8) | 106.1 (8.9) | 108.2 (12.6) |
| TMT – A time in seconds | 35.7 (12.8) | 48.1 (22.2) | 67.1 (31.0) | 43.8 (21.7) |
| TMT – A errors | 0.12 (0.35) | 0.18 (0.46) | 0.16 (0.45) | 0.15 (0.41) |
| TMT – B time in seconds | 81.5 (36.1) | 136.0 (78.0) | 190.8 (81.6) | 114.1 (71.0) |
| TMT – B errors | 0.45 (0.85) | 1.05 (1.22) | 1.39 (1.31) | 0.78 (1.11) |
Note: Data presented as Mean (standard deviation) or percentages (%); MCI = mild cognitive impairment; AD = Alzheimer’s disease; WRAT-3 = Wide Range Achievement Test – 3rd Edition; TMT = Trail Making Test