Table 2.
The change in cognition predicted by the biomarker baseline and the biomarker slope for MCs only
| Participants | Biomarker | Change in cognition predicted by the biomarker baseline, mean (SE) | Change in cognition predicted by the biomarker slope, mean (SE) | Change in cognition, mean (SE)∗ | Change in biomarker, mean (SE) | Biomarker baseline mean (SE) |
|---|---|---|---|---|---|---|
| Mean PiB PET | −0.15 (0.085)† [P = .07] | 0.55 (1.13)§ [P = .63] | 0.17 (0.11) [P = .12] | 0.073 (0.010) [P < .0001] | 2.08 (0.08) [P < .0001] | |
| MC | FDG PET | 0.12 (0.21) [P = .58] | 3.74 (1.10) [P = .008] | −0.27 (0.36) [P = .46] | −0.009 (0.004) [P = .018] | 1.67 (0.01) [P < .0001] |
| MRI hippocampal volume‡ | 0.06 (0.02) [P = .009] | 0.99 (0.11) [P < .0001] | −0.01 (0.02) [P = .44] | −0.11 (0.01) [P < .0001] | 0.09 (0.07) [P = .19] | |
| CSF Aβ42‡ | 0.08 (0.02) [P = .002] | 0.18 (0.175) [P = .31] | −0.09 (0.02) [P < .0001] | −0.07 (0.01) [P < .0001] | −0.08 (0.08) [P = .33] | |
| Total tau‡ | −0.12 (0.02) [P < .0001] | 0.20 (0.31) [P = .52] | −0.13 (0.02) [P < .0001] | 0.027 (0.014) [P = .05] | −0.10 (0.06) [P = .14] | |
| Ptau‡ | −0.11 (0.03) [P < .0001] | 0.98 (1.07) [P = .36] | −0.13 (0.02) [P < .0001] | 0.01 (0.012) [P = .37] | −0.1 (0.06) [P = .12] |
Abbreviations: MC, mutation carrier; FDG, [F-18] fluorodeoxyglucose; MRI, magnetic resonance imaging; PET, positron emission tomography; PiB, [C-11] Pittsburgh compound B.
The bold values indicate significant association at a Type I error level 0.05.
This change is conditioned on the change in cognition predicted by the biomarker baseline and by the biomarker slope.
Negative sign means 1-unit increase in biomarker will lead to a decrease in the rate of change in cognition.
Outcomes are standardized to have mean 0 and SD 1 for ease of computation and interpretation.
The magnitude of the coefficient estimates associated with the longitudinal change is larger than that of the baseline due to the fact that the magnitude of the longitudinal change itself is smaller than that of the baseline. Thus, a one-unit change in the longitudinal change corresponds to a larger change in the cognition.