Table 3.
Demographic characteristics, mean performance, and frequency of low test performance across CU and MCI biomarker subgroups.
| CU A−T− (n = 146) |
MCI A+T+ (n = 15) |
p- value for CU A−T− and MCI A+T+ |
MCI A−T− (n = 14) |
p- value for MCI A−T− and MCI A+T+ |
|
|---|---|---|---|---|---|
| Age Mean (SD) | 66.32 (12.06) | 82.58 (4.28) | <0.001a | 72.50 (12.55) | 0.007a |
| Education Mean (SD) | 15.24 (2.44) | 14.33 (2.50) | 0.173a | 13.36 (2.37) | 0.291a |
| Sex (% Male) | 78 (53.4%) | 9 (60.0%) | 0.627b | 8 (57.1%) | 0.876b |
| Short Test of Mental Status c | 36.18 (1.99) | 32.00 (2.36) | <0.001a | 32.14 (3.21) | 0.892a |
| CBB Lrn/WM Composite Mean (z) | 0.21 (0.78) | −1.49 (0.99) | <0.001a | −0.19 (0.75) | <0.001a |
| CBB Lrn/WM Composite | <0.001b | 0.001b | |||
| Normal z > −1 | 138 (95.2%) | 4 (26.7%) | 12 (85.7%) | ||
| z ≤ −1 | 7 (4.8%) | 11 (73.3%) | 2 (14.3%) | ||
| CBB Attn/Psychomotor Mean (z score) | −0.71 (1.13) | −1.26 (1.14) | 0.077a | −1.54 (1.35) | 0.548a |
| CBB Attn/Psychomotor Composite | 0.082b | 0.588b | |||
| Normal z > −1 | 92 (63.0%) | 6 (40.0%) | 7 (50%) | ||
| z ≤ −1 | 54 (37.0%) | 9 (60.0%) | 7 (50%) |
a
p-values represent linear model ANOVAs for mean comparisons.
b
p-values represent Pearson’s Chi-squared test for frequency comparisons.
c
Performance is considered as part of consensus diagnosis.
Note. CU = cognitively unimpaired; A = amyloid; T = tau; MCI = mild cognitive impairment; CBB = Cogstate Brief Battery; Lrn/WM = Learning / Working Memory; Attn = Attention.