Table 2.
The diagnostic evaluation of induration and erythema after EC skin test
| Diagnostic index | Different times | χ2 | P | ||
|---|---|---|---|---|---|
| 24 h | 48 h | 72 h | |||
| Induration results | |||||
| Sensitivity | 72.14%a | 84.25% | 83.78% | 43.80 | < 0.01 |
| Specificity | 97.49%a | 91.15% | – | 56.81 | < 0.01 |
| PV+ | 93.38%a | 82.37% | – | 35.30 | < 0.01 |
| PV− | 87.70%a | 92.18% | – | 17.41 | < 0.01 |
| Consistency | 89.14%a | 88.88% | – | 0.08 | 0.78 |
| YI | 69.63% | 75.40% | – | ||
| Kappa (95% CI) | 0.74 (0.71, 0.77) | 0.75 (0.72, 0.78) | – | ||
| Erythema results | |||||
| Sensitivity | 85.33%a | 90.85% | 91.08% | 16.18 | < 0.01 |
| Specificity | 95.38%a | 89.83% | – | 34.02 | < 0.01 |
| PV+ | 90.06%a | 81.42% | – | 22.74 | < 0.01 |
| PV− | 92.98%a | 95.24% | – | 6.78 | 0.01 |
| Consistency | 92.07%a | 90.16% | – | 5.06 | 0.02 |
| YI | 80.71% | 80.68% | – | ||
| Kappa (95% CI) | 0.82 (0.79, 0.85) | 0.78 (0.75, 0.81) | – | ||
PV+ Positive predict value, PV− Negative predict value, YI Youden index
acompared with 48 h and 72 h or compared with 48 h