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Table 4 Diagnostic performance of different CSF analytes measured with the INNOTEST assay for Aβ42, ttau, and ptau at an optimal specificity and at a specificity fixed at 90 % or 95 %

From: Diagnostic value of cerebrospinal fluid Aβ ratios in preclinical Alzheimer’s disease

  AUC SE 95 % CI Cutoffa Sensitivity (%) Specificity (%) Correctly classifiedb (%)
Aβ42 0.935 0.0394 0.806–0.989 853 100 83.87 87
ttau 0.733 0.132 0.565–0.863 352 71.43 77.42 76
ptau 0.675 0.139 0.504–0.818 86 42.86 93.55 84
Aβ42/ttau 0.880 0.0878 0.734–0.963 2.258 85.71 90.32 89
Specificity of 90 % Sensitivity (%) 95 % CI Cutoffa Differencec (%) P valued Correctly classifiedb (%)
 Aβ42 85.71 11.54–100.00 798 7.90 0.25 89
 ttau 57.14 14.29–100.00 465 10.53 0.125 82
 ptau 42.96 0.00–85.71 87 5.26 0.5 79
 Aβ42/ttau 85.71 28.57–100.00 2.263 0 1 89
Specificity of 95 % Sensitivity (%) 95 % CI Cutoffa Differencec (%) P valued Correctly classifiedb (%)
 Aβ42 42.86 4.05–100.00 672 21.05 0.008 87
 ttau 14.29 0.00–85.71 566 23.69 0.004 82
 ptau 28.57 0.00–71.43 94 2.63 1 82
 Aβ42/ttau 71.43 8.71–100.00 2.093 7.90 0.25 92
  1. Analyte concentrations are described as pg/ml or calculated as ratios between concentrations of two analytes
  2. aCutoff value corresponding to the highest Youden index
  3. bPercentage of positively classified cases based on the CSF cutoff value compared with amyloid PET classification
  4. cPercentage of subjects who were classified differently based on the cutoff values from fixed specificities compared with the cutoff values corresponding to the highest Youden index
  5. dSignificance for the “Difference”
  6. amyloid beta, AUC area under the receiver operating characteristic curve, CI confidence interval, CSF cerebrospinal fluid, PET positron emission tomography, ptau 181phospho-tau, SE standard error, ttau total tau