ROC analysis of CSF parameters
| CSF variables | Number of patients† | Youden index‡ | Associated criterion§ | Se (%) | Sp (%) | AUC (95% CI) | Cut-off used * | |
| Se (%) | Sp (%) | |||||||
| Pro-DLB versus pro-AD | ||||||||
| t-Tau | DLB n=57 AD n=132 | 0.682 | >443 ng/L | 73.5 | 94.7 | 0.91 (0.86 to 0.94) | 81.8 | 84.2 |
| Ph-Tau | 0.799 | >62 ng/L | 88.6 | 91.2 | 0.93 (0.89 to 0.97) | 90.2 | 86.0 | |
| Aβ42 | 0.471 | ≤626 ng/L | 68.2 | 79 | 0.76 (0.69 to 0.82) | 76.5 | 68.4 | |
| t-Tau _ phospho-Tau _ Aβ42¶ | 0.794 | >0.604 | 86.4 | 93.0 | 0.93 (0.89 to 0.97) | |||
| Aβ40 | DLB n=33 AD n=60 | 0.591 | >9546 | 83.3 | 75.8 | 0.80 (0.71 to 0.88) | ||
| Aβ42/Aβ40 | 0.783 | ≤0.0556 | 78.3 | 100 | 0.95 (0.88 to 0.98) | |||
| t-Tau _ phospho-Tau _ Aβ42/Aβ40¶ | 0.873 | >0.573 | 93.3 | 93.9 | 0.97 (0.91 to 1.00) | |||
| DLB-d versus AD-d | ||||||||
| t-Tau | DLB n=154 AD n=783 | 0.616 | >443 ng/L | 81.7 | 79.9 | 0.87 (0.84 to 0.89) | 86.2 | 74.7 |
| Ph-Tau | 0.636 | >64 ng/L | 87.6 | 76.0 | 0.87 (0.85 to 0.90) | 91.1 | 70.8 | |
| Aβ42 | 0.243 | ≤606 ng/L | 71.0 | 53.3 | 0.64 (0.61 to 0.67) | 84.6 | 37.0 | |
| t-Tau _ phospho-Tau _ Aβ42¶ | 0.609 | >0.769 | 77.1 | 83.8 | 0.87 (0.85 to 0.89) | |||
| Aβ40 | DLB n=43 AD n=281 | 0.389 | >7316 | 85.4 | 53.5 | 0.72 (0.67 to 0.77) | ||
| Aβ42/Aβ40 | 0.400 | ≤0.0821 | 86.5 | 53.5 | 0.72 (0.67 to 0.77) | |||
| t-Tau _ phospho-Tau _ Aβ42/Aβ40¶ | 0.512 | >0.765 | 86.1 | 65.1 | 0.83 (0.78 to 0.87) | |||
| DLB-(Pro+d) versus AD-(Pro+d)** | ||||||||
| t-Tau | DLB n=211 DLB/AD n=915 | 0.644 | >443 ng/L | 80.6 | 83.9 | 0.88 (0.86 to 0.90) | 85.6 | 77.3 |
| Ph-Tau | 0.675 | >63 ng/L | 88.3 | 79.2 | 0.89 (0.87 to 0.91) | 91 | 74.9 | |
| t-Tau _ phospho-Tau¶ | 0.683 | >0.696 | 88.2 | 80.1 | 0.90 (0.88 to 0.91) | |||
| Aβ40 | DLB n=76 DLB/AD n=341 | 0.367 | >9932 | 60.4 | 76.3 | 0.71 (0.67 to 0.76) | ||
| Aβ42/Aβ40 | 0.498 | ≤0.0692 | 74.8 | 75 | 0.80 (0.76 to 0.84) | |||
| t-Tau _ phospho-Tau _ Aβ42/Aβ40¶ | 0.609 | >0.734 | 80.7 | 80.3 | 0.87 (0.84 to 0.90) | |||
*Tau >400 ng/L; Aβ42 <700 ng/L; Ph-Tau >60 ng/L.
†Due to missing CSF, some patients could not have an Aβ40 assay.
‡Youden index: sensitivity+specificity – 1.
§Cut-off point associated to the Youden index.
¶Consideration of these parameters with a multiple regression.
**DLB-(Pro+d)=pro-DLB+DLB-d groups; AD-(Pro+d)=pro-AD+AD-d groups.
AD, Alzheimer’s disease; AD-d, AD at demented stage; AUC, area under the ROC curve; CSF, cerebrospinal fluid; DLB, dementia with Lewy bodies; DLB-d, DLB at demented stage; pro-AD, AD at prodromal stage; pro-DLB, DLB at prodromal stage; ROC, receiver-operator curve; Se, sensitivity; Sp, specificity.