Table 2.
Performance indicators and levels of agreement for the overall assay (OVA)’s results.a
| Criterion | Sensitivity (%) | Specificity (%) | Positive predictive value (%) | Negative predictive value (%) | McNemar’s test p-value | Cohen’s kappa |
|---|---|---|---|---|---|---|
| Pre-immunization titer (mg/L) | ||||||
| ≤26b | 64.3 (48.0–78.4) | 75.0 (50.9–91.3) | 84.4 (67.2–94.7) | 50.0 (31.3–68.7) | 0.154 | 0,31 (0.08–0.53) |
| Post-immunization titer (mg/L) | ||||||
| ≤110 | 57.8 (38.7–70.2) | 100.0 (83.2–100.0) | 100.0 (85.2–100.0) | 51.3 (34.8–67.6) | 0.761 | 0.53 (0.39–0.66) |
| ≤230b | 88.1 (74.4–96.0) | 80.0 (56.3–94.3) | 90.2 (76.9–97.3) | 76.2 (52.8–91.8) | 0.008 | 0.52 (0.29–0.75) |
| Post-immunization increase in titer (mg/L) | ||||||
| ≤139b | 81.0 (65.9–91.4) | 90 (68.3–98.8) | 94.4 (81.3–99.3) | 69.2 (48.2–85.7) | 0.049 | 0.57 (0.36–0.79) |
| Post-/pre-ratio | ||||||
| ≤4.9b | 66.7 (50.5–80.4) | 80 (56.3–94.3) | 87.5 (71.0–96.5) | 53.3 (34.3–71.7) | 0.126 | 0.39 (0.17–0.60) |
aComparatively to the vaccine response status as assessed by the serotype-specific assay and using the American Academy of Asthma, Allergy and Immunology criteria (2).
bSelected using the Youden index. The selected threshold’s performances are highlighted in bold font.
All statistics are presented with the corresponding (95% confidence interval).