Table 1

Cut-off values of AT(N) biomarkers based on different models

Analysed samplesAβ42p-tau181t-tauNfL
Aβ PET− (n=47) vs Aβ PET+ (n=53)
 Area under the ROC curve (95% CI)0.940 (0.885 to 0.995)0.868 (0.794 to 0.941)0.898 (0.832 to 0.963)0.706 (0.591 to 0.821)
 Cut-off value, pg/mL378.726.885.72428
 Sensitivity, % (95% CI)98.1 (90.1 to 99.9)83.0 (70.8 to 90.8)90.6 (79.8 to 95.9)89.1 (77.0 to 95.3)
 Specificity, % (95% CI)85.1 (72.3 to 92.6)80.9 (67.5 to 89.6)80.9 (67.5 to 89.6)57.1 (42.2 to 70.9)
CU, Aβ PET− (n=31) vs ADD, Aβ PET+ (n=22)
 Area under the ROC curve0.962 (0.907 to 1.000)0.912 (0.834 to 0.990)0.963 (0.917 to 1.000)0.852 (0.735 to 0.969)
 Cut-off value, pg/mL361.629.188.82650
 Sensitivity, % (95% CI)100 (85.1 to 100)95.5 (78.2 to 99.8)95.5 (78.2 to 99.8)85.0 (64.0 to 94.8)
 Specificity, % (95% CI)87.1 (71.2 to 94.9)80.7 (63.7 to 90.8)90.3 (75.1 to 96.7)80.8 (62.1 to 91.5)
CU (n=53) vs ADD (n=56)
 Area under the ROC curve0.888 (0.821 to 0.954)0.805 (0.723 to 0.888)0.882 (0.818 to 0.947)0.831 (0.747 to 0.915)
 Cut-off value, pg/mL288.629.091.03120
 Sensitivity, % (95% CI)82.1 (70.2 to 90.0)73.2 (60.4 to 83.0)76.8 (64.2 to 85.9)69.4 (55.5 to 80.5)
 Specificity, % (95% CI)88.7 (77.4 to 94.7)79.3 (66.5 to 88.0)88.7 (77.4 to 94.7)89.1 (77.0 to 95.3)
Gaussian Mixture Model (n=194)
 Cut-off value, pg/mL359.630.6105.3NA*
  • The cutoffs were established at the highest Youden Index (sensitivity +specificity – 1) when comparing Aβ PET− with Aβ PET+, or comparing CU, Aβ PET− with ADD, Aβ PET+, or comparing CU with ADD. The sensitivity and specificity are for each cut-off value.

  • *Due to unimodal distribution.

  • ADD, Alzheimer’s disease dementia; Aβ, β-amyloid; CU, cognitively unimpaired subjects; NA, not available; NfL, neurofilament light chain; p-tau181, tau phosphorylated at threonine 181; ROC, receiver operating characteristic; t-tau, total tau.