Table 1.
Demographic and key characteristics of the sample
| CU | MCI | P-value | |
|---|---|---|---|
| No. | 509 | 604 | – |
| Age, year, mean (SD) | 73.75 (5.83) | 72.19 (7.47) | <0.0001 |
| Female, no. (%) | 260 (51) | 257 (42.5) | 0.004 |
| Education, year, mean (SD) | 16.55 (2.58) | 16.03 (2.8) | <0.0001 |
| Racial category | |||
| American Indian/Alaskan Native | 1 (0) | 1 (0) | |
| Asian | 9 (1.7) | 8 (1) | |
| Black | 25 (4.9) | 17 (3) | |
| Hawaiian/Pacific Islander | 0 (0) | 2 (0) | |
| More than one | 11 (2.2) | 6 (1) | |
| White | 460 (90.3) | 563 (93) | |
| Unknown/not reported | 2 (0) | 7 (1) | |
| Ethnic category | |||
| Hispanic/Latinx | 19 (3.7) | 19 (3.2) | |
| Not Hispanic/Latinx | 484 (95) | 580 (96) | |
| Unknown/not reported | 4 (0.7) | 5 (0.8) | |
| APOE ε4 carriers, % | 145 (28.5) | 289 (47.8) | <0.0001 |
| MMSE, mean (SD) | 29.02 (1.2) | 27.25 (3.31) | <0.0001 |
| Baseline memory z-score (SD) | 0.00 (0.66) | −1.16 (0.99) | <0.0001 |
| Baseline plasma p-tau181, pg/ml, mean (SD) | 16.25 (9.99) | 19.01 (12.07) | <0.0001 |
Mean and standard deviation (SD) are provided for continuous variables and n and % are provided for dichotomous variables. P-values indicate values assessed with two-sided independent samples t-tests for each variable except sex and APOE ε4 status, where contingency chi-square tests were performed. P-values reported are for comparisons to CU subjects.
CU = cognitively unimpaired; MCI = mild cognitive impairment; MMSE = mini-mental state examination; p-tau181 = phosphorylated tau at threonine 181.