TABLE 3.
Single cutoff values (bolded) for p‐tau217 (ALZPath) along with corresponding sensitivity and specificity to Aβ‐PET results for the overall combined sample (“All”) and reported separately for each ethnicity‐specific analysis.
| Plasma p‐tau217 (ALZPath) | ||||
|---|---|---|---|---|
| Aβ‐PET result | All | Non‐Hispanic/Latino White | Hispanic/Latino White | |
| Visual read (positive vs. negative) | Single cutoff, pg/mL | 0.55 | 0.55 | 0.60 |
| Sens/Spec (group‐specific) a | 89.0/82.4 | 86.0/85.1 | 91.1/86.8 | |
| PPV/NPV (group‐specific) | 75.7/93.2 | 78.7/90.8 | 82.4/93.8 | |
| Sens/Spec (universal) b | 89.0/82.4 | 86.0/85.1 | 93.3/83.8 | |
| PPV/NPV (universal) | 75.7/93.2 | 78.7/90.8 | 79.6/95.1 | |
| CL quantification (CL < 25 vs. CL ≥ 25) | Single cutoff, pg/mL | 0.56 | 0.55 | 0.60 |
| Sens/Spec (group‐specific) | 84.6/87.4 | 86.7/87.7 | 86.5/91.8 | |
| PPV/NPV (group‐specific) | 81.9/88.8 | 83.0/90.8 | 88.2/89.1 | |
| Sens/Spec (universal) | 84.6/87.4 | 86.7/87.7 | 86.5/88.5 | |
| PPV/NPV (universal) | 81.9/88.8 | 83.0/90.8 | 86.5/88.9 | |
| High PET (CL > 49) vs. Low PET (CL < 10) | Single cutoff, pg/mL | 0.56 | 0.56 | 0.61 |
| Sens/Spec (group‐specific) | 94.4/87.0 | 94.1/88.5 | 94.4/91.5 | |
| PPV/NPV (group‐specific) | 80.7/96.0 | 84.2/96.0 | 85.7/92.5 | |
| Sens/Spec (universal) | 94.4/87.0 | 94.1/88.5 | 94.4/89.4 | |
| PPV/NPV (universal) | 80.7/96.0 | 84.2/96.0 | 85.0/95.6 | |
| Intermediate PET (CL 10–49) vs. Low PET (CL < 10) | Single cutoff, pg/mL | 0.39 | 0.30 | 0.37 |
| Sens/Spec (group‐specific) | 66.1/66.6 | 87.5/48.1 | 73.3/72.3 | |
| PPV/NPV (group‐specific) | 48.6/77.7 | 43.8/90.0 | 60.0/79.5 | |
| Sens/Spec (universal) | 66.1/66.6 | 66.7/62.5 | 66.7/72.3 | |
| PPV/NPV (universal) | 48.6/77.7 | 44.1/79.5 | 58.8/77.8 | |
Abbreviations: Aβ‐PET, beta‐amyloid positron emission tomography; CL, Centiloids; PET, positron emission tomography.
aSensitivity (Sens) and Specificity (Spec) / positive predictive value (PPV) and negative predictive value (NPV) when applying the single cutoff (Youden's Index) derived from group‐specific area under the curve (AUC) curve.
Sensitivity (Sens) and Specificity (Spec) / positive predictive value (PPV) and negative predictive value (NPV) when universally applying the single cutoff (Youden's Index) derived from overall (“All”) sample area under the curve (AUC) curve to each subgroup. PPV and NPV refer only to this cohort and do not account for known or expected prevalence of disease (AD) in the population.