Table 3.
ROC curve analysis and calculated cutoff values for the five SARS-CoV-2 antibody assays
| Roche | Abbott | Siemens | SD Biosensor | LG Chem | |
|---|---|---|---|---|---|
| AUC (P) | 0.976 (P < 0.001) | 0.987 (P < 0.001) | 0.984 (P < 0.001) | 0.994 (P < 0.001) | 0.987 (P < 0.001) |
| Manufacturer’s cutoff | 1.0 COI | 1.4 index | 1.0 index | (NC+0.3) OD | 1.0 S/CO |
| Sensitivity % (95% CI) according to the manufacturer’s cutoff | 93.5 (90.6–95.7) | 92.2 (90.0–95.3) | 95.7 (93.2–97.5) | 98.0 (96.1–99.1) | 97.0 (94.5–98.2) |
| Specificity % (95% CI) according to the manufacturer’s cutoff | 99.7 (98.9–100) | 99.4 (98.5–99.8) | 100 (99.5–100) | 99.3 (98.3–99.8) | 97.5 (95.9–98.4) |
| Cutoff calculated based on the Youden index | 0.19 COI | 0.44 index | 0.57 index | 0.40 OD | 1.16 S/CO |
| Sensitivity % (95% CI) according to the calculated cutoff | 96.5 (94.2–98.1) | 96.2 (93.9–97.9) | 96.7 (94.5–98.2) | 97.7 (95.7–99.0) | 96.7 (94.5–98.2) |
| Specificity % (95% CI) according to the calculated cutoff | 98.1 (96.8–99.0) | 99.0 (97.9–99.6) | 99.6 (98.7–99.9) | 99.4 (98.5–99.8) | 98.0 (96.6–98.9) |
Abbreviations: AUC, area under the curve; COI, cutoff index; NC, negative control; OD, optical density; S/CO, signal/cutoff; CI, confidence interval; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.