Table 2.
Performance of Chest CT in diagnosing COVID-19 with RT-PCR Results as Standard of Reference.
| Results (n) |
Test performance (%) |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TP | TN | FP | FN | Positive RT-PCR | Sensitivity (95 % CI) | p-value | Specificity (95 % CI) | p-value | PPV (95 % CI) | p-value | NPV (95 % CI) | p-value | Accuracy (95 % CI) | p-value | |
| Overall | |||||||||||||||
| 419 | 245 | 66 | 43 | 462 (59.8) | 90.7 (87.7−93.2) | 78.8 (73.8−83.2) | 86.4 (83.6−88.7) | 85.1 (81−88.4) | 85.9 (83.2−88.3) | ||||||
| Age | |||||||||||||||
| <50 | 81 | 94 | 16 | 15 | 96 (46.6) | 84.4 (75.5−91) | 0.017 | 85.4 (76.5−91.4) | 0.033 | 83.5 (76.1−88.9) | 0.354 | 86.2 (79.6−91) | 0.664 | 85 (79.3−89.5) | 0.899 |
| ≥50 | 338 | 151 | 50 | 28 | 366 (64.5) | 90.7 (89.1−94.9) | 75.1 (68.5−80.9) | 87.1 (84.1−89.6) | 84.4 (78.9−88.6) | 86.2 (83.1−89) | |||||
| <60 | 166 | 126 | 29 | 19 | 185 (54.4) | 89.7 (84.4−93.7) | 0.888 | 81.3 (74.2−87.1) | 0.280 | 85.1 (80.4−88.9) | 0.506 | 86.9 (81.1−91.1) | 0.381 | 85.9 (81.7−89.4) | 0.997 |
| ≥60 | 253 | 119 | 37 | 24 | 277 (63.9) | 91.3 (87.4−94.4) | 76.3 (68.8−82.7) | 87.2 (83.7−90) | 83.2 (77−88) | 85.9 (82.3−89) | |||||
| Sex | |||||||||||||||
| Male | 261 | 108 | 33 | 21 | 282 (66.6) | 92.5 (88.8−95.3) | 0.08 | 76.6 (68.7−83.3) | 0.39 | 88.8 (85.4−91.4) | 0.057 | 83.7 (77.1−88.7) | 0.562 | 87.3 (83.7−90.3) | 0.746 |
| Female | 158 | 137 | 33 | 22 | 180 (51.4) | 87.8 (82.1−92.2) | 80.6 (73.4−86.2) | 82.7 (77.8−86.7) | 86.2 (80.7−90.3) | 84.3 (80−87.9) | |||||
Note: for positive RT-PCR, data are patients with percentages in parentheses; the other data in brackets are 95 % confidence interval.
Abbreviation: TP, true positive; TN, true negative; FP, false positive; FN, false negative; PPV, positive predictive value; NPV, negative predictive value; RT-PCR, reversed transcription polymerase chain reaction.