Table 2.

ROC curves.

Categorical variables	ADNIAUCs (95% CI)	SILCODEAUCs (95% CI)
Pattern trained by itself	0.815 (0.730–0.899)	0.745 (0.615–0.876)
Pattern trained by the other	0.700 (0.596–0.805)	0.696 (0.615–0.836)
MMSE	0.603 (0.488–0.718)	0.591 (0.437–0.744)
MoCA	0.580 (0.466–0.695)	0.593 (0.440–0.746)
Pattern (itself) + MMSE + MoCA	0.824 (0.743–0.905)	0.784 (0.662–0.906)
Pattern (the other) + MMSE + MoCA	0.706 (0.601–0.811)	0.732 (0.600–0.864)
Pattern trained by the two cohorts	0.729 (0.629–0.830)	0.739 (0.608–0.869)
Pattern (two cohorts) + MMSE + MoCA	0.748 (0.650–0.846)	0.745 (0.614–0.877)
FDG SUVR of the medial temporal lobe	0.578 (0.463–0.693)	0.528 (0.370–0.686)
Voxel-wise SPM pattern (itself)	0.667 (0.558–0.776)	0.513 (0.358–0.668)
Voxel-wise SPM pattern (the other)	0.560 (0.445–0.676)	0.617 (0.468–0.767)
Voxel-wise SPM pattern (two cohorts)	0.657 (0.547–0.766)	0.571 (0.419–0.723)

ROC curves were used to distinguish Aβ+ NCs from Aβ- NCs in the two cohorts. In the ADNI (SILCODE) cohort, the pattern trained by ‘itself’ indicates that the pattern was acquired from the ADNI (SILCODE) cohort, and the pattern trained by ‘the other’ indicates that the pattern was acquired from the SILCODE (ADNI) cohort. The pattern trained by the ‘two cohorts’ indicates that the pattern was acquired from the combined two cohorts. Abbreviations: AUCs, areas under the curve; ROC, receiver operating characteristic; ADNI, Alzheimer’s Disease Neuroimaging Initiative; SILCODE, Sino Longitudinal Study on Cognitive Decline; CI, confidence interval; Aβ, β-amyloid; NCs, cognitively normal controls; MMSE, Mini-Mental State Examination; MoCA, Montreal Cognitive Assessment; FDG, fluoro-2-deoxyglucose; SUVR, standardized uptake value ratio.