Severity score | Optimal cut-off score | AUROC | Difference (95% CI)# | Positive-predictive value % | Negative-predictive value % | p-value* |
CURB-65 | ||||||
Original | 2 | 0.658 | NA | 20.5 | 92.2 | |
CXR-modified CURB-65 | 3 | 0.664 | 0.006 (−0.040 to 0.056) | 26.2 | 87.4 | 0.795 |
Chest CT-modified CURB-65 | 4 | 0.866 | 0.207 (0.136 to 0.283) | 80.8 | 78.6 | <0.001 |
A-DROP | ||||||
Original | 3 | 0.756 | NA | 64.0 | 83.9 | |
CXR-modified A-DROP | 3 | 0.737 | −0.020 (−0.062 to 0.031) | 36.0 | 88.2 | 0.425 |
Chest CT-modified A-DROP | 4 | 0.891 | 0.134 (0.081 to 0.194) | 89.5 | 79.8 | <0.001 |
AUROC: area under the receiver operator characteristic curve; CURB-65: confusion, urea >7 mmol·L−1, respiratory rate ≥30 breaths·min−1, blood pressure <90 mmHg (systolic) ≤60 mmHg (diastolic), age ≥65 years; CT: computed tomography; CXR: chest radiograph; NA: not applicable. #: difference of AUROC from the original score. *: compared with each original score (CURB-65 or A-DROP) of AUC. p<0.001, for comparison between chest CT-modified and CXR-modified CURB-65 and A-DROP values.