Classification results of the external validation
| Results | Hong Kong | |
| Point estimate | 95% CI | |
| Specificity | 0.911 | 0.891 to 0.932 |
| Sensitivity | 0.995 | 0.990 to 1.000 |
| PPV | 0.910 | 0.889 to 0.931 |
| NPV | 0.996 | 0.991 to 1.000 |
NPV, negative predictive value; PPV, positive predictive value.