Table 1.
The PPA, NPA, and Concordance of the Evaluated Assays Relative to the Reference Values
| Test | Reference value∗ |
kappa | PPA (95% CI) | NPA (95% CI) | ||
|---|---|---|---|---|---|---|
| + | - | |||||
| LDT | + | 87 | 0 | 0.988 (0.966–1.0) | 98.9% (93.83–99.97) | 100% (95.75–100) |
| − | 1 | 85 | ||||
| Cobas | + | 88 | 9 | 0.896 (0.830–0.962) | 100% (95.89–100) | 89.4% (80.85–95.04) |
| − | 0 | 76 | ||||
| Amplidiag | + | 87 | 1 | 0.977 (0.945–1.0) | 98.9% (93.96–99.97) | 98.8% (93.62–99.97) |
| − | 1 | 84 | ||||
LDT, laboratory-developed test; NPA, negative percent agreement, PPA, positive percent agreement.
∗
“Consensus result” was used as a reference value and was defined as the result obtained by at least two of the three studied methods.