Table 2.
Method validation studies
| Mfg-1 | Lab A | Lab B | Mfg-2 | Lab C | Lab D | |
|---|---|---|---|---|---|---|
| Known positives | 30 | 46 | 33 | 45 | 5 | 220 |
| Known negatives | 30 | 15 | 546 | 45 | 3 | 261 |
| PPA reported | 100% | 71.7% | 78.8% | 97.8% | 100.0% | 99.5% |
| Confidence intervals | 88.0% - 100% | 56.6% - 83.8% | 61.2% - 90.9% | 87.8% - 100% | 54.6% - 100% | 97.3 %- 100% |
| NPA reported | 100% | 100% | 100% | 95.60% | 100% | 95.80% |
| Confidence intervals | 88.0% - 100% | 78.5% - 100% | 99.3% - 100% | 84.5% - 100% | 41.9% - 100% | 92.5% - 97.9% |
| Pos likelihood ratio (LR+) | 999.9 | 999.9 | 999.9 | 22.2 | 999.9 | 23.7 |
| Confidence intervals | 7.3-999.9 | 2.6-999.9 | 82.6-999.9 | 7.3-999.9 | 0.94-999.9 | 12.91-999.9 |
| Neg likelihood ratio (LR-) | 0.00 | 0.28 | 0.21 | 0.023 | 0.00 | 0.005 |
| Confidence intervals | 0-0.14 | 0.16-0.55 | 0.09-0.39 | 0-0.14 | 0-1.08 | 0.09-0.39 |