Diagnostic Performance of Lung US Compared With Chest Radiography, in Full Cohort and in Subgroups
| Chest Radiography Result | |||||
|---|---|---|---|---|---|
| Lung US Result | Positive, No. (%) | Negative, No. (%) | Total, No. (%) | OR (95% CI) [P Value] | Diagnostic Performance of Lung US, Value (95% CI) |
| Full cohort | |||||
| Positive lung US | 36 (87.8) | 17 (41.5) | 53 (64.6) | 10.2 (3.3-31.2) | Sensitivity: 0.88 (0.75-0.95); specificity: 0.59 (0.43-0.72); PPV: 0.68 (0.55-0.79); NPV: 0.83 (0.66-0.92); positive LR: 2.12 (1.45-3.10); negative LR: 0.21 (0.09-0.49) |
| Negative lung US | 5 (12.2) | 24 (58.5) | 29 (35.4) | [<.001] | |
| Total | 41 (100) | 41 (100) | 82 (100) | ||
| Patients’ age group Pediatric | |||||
| Positive lung US | 8 (100) | 1 (14.3) | 9 (60.0) | 96a (2.7-3,362) | Sensitivity: 1 (0.68-1); specificity: 0.86 (0.49-0.97); PPV: 0.89 (0.57-0.98); NPV: 1 (0.61-1); positive LR: 6.99 (1.14-42.97); negative LR: not calculable |
| Negative lung US | 0 (0) | 6 (85.7) | 6 (40.0) | [.001] | |
| Total | 8 (100) | 7 (100) | 15 (100) | ||
| Adult | |||||
| Positive lung US | 28 (84.8) | 16 (47.1) | 44 (65.7) | 6.3 (2.0-20.2) | Sensitivity: 0.85 (0.69-0.93); specificity: 0.53 (0.37-0.69); PPV: 0.64 (0.49-0.76); NPV: 0.78 (0.58-0.90); positive LR: 1.80 (1.23-2.65); negative LR: 0.29 (0.12-0.68) |
| Negative lung US | 5 (15.2) | 18 (52.9) | 23 (34.3) | [.001] | |
| Total | 33 (100) | 34 (100) | 67 (100) | ||
| Physicians’ accredited US training time | |||||
| <100 hours | |||||
| Positive lung US | 18 (90.0) | 6 (35.3) | 24 (64.9) | 16.5 (2.8-96.7) | Sensitivity: 0.90 (0.70-0.97); specificity: 0.65 (0.41-0.83); PPV: 0.75 (0.55-0.88); NPV: 0.85 (0.58-0.96); positive LR: 2.55 (1.32-4.93); negative LR: 0.16 (0.04-0.60) |
| Negative lung US | 2 (10.0) | 11 (64.7) | 13 (35.1) | [.001] | |
| Total | 20 (100) | 17 (100) | 37 (100) | ||
| ≥100 hours | |||||
| Positive lung US | 18 (85.7) | 11 (45.8) | 29 (64.4) | 7.1 (1.6-30.6) | Sensitivity: 0.86 (0.65-0.95); specificity: 0.54 (0.35-0.72); PPV: 0.32 (0.44-0.77); NPV: 0.81 (0.57-0.93); positive LR: 1.87 (1.17-2.99); negative LR: 0.26 (0.09-0.80) |
| Negative lung US | 3 (14.3) | 13 (54.2) | 16 (35.6) | [.005] | |
| Total | 21 (100) | 24 (100) | 45 (100) | ||
| Physicians’ experience using US | |||||
| <3 years | |||||
| Positive lung US | 7 (100) | 3 (37.5) | 10 (66.7) | 23.3a (1.0-576.1) | Sensitivity: 1 (0.65-1); specificity: 0.63 (0.31-0.86); PPV: 0.70 (0.40-0.89); NPV: 1 (0.57-1); positive LR: 2.67 (1.09-6.52); negative LR: not calculable |
| Negative lung US | 0 (0) | 5 (62.5) | 5 (33.3) | [.03] | |
| Total | 7 (100) | 8 (100) | 15 (100) | ||
| 3-6 years | |||||
| Positive lung US | 20 (83.3) | 5 (35.7) | 25 (65.8) | 9 (1.9-41.7) | Sensitivity: 0.83 (0.64-0.93); specificity: 0.64 (0.39-0.84); PPV: 0.80 (0.61-0.91); NPV: 0.69 (0.42-0.87); positive LR: 2.33 (1.13-4.82); negative LR: 0.26 (0.10-0.69) |
| Negative lung US | 4 (16.7) | 9 (64.3) | 13 (34.2) | [.005] | |
| Total | 24 (100) | 14 (100) | 38 (100) | ||
| >6 years | |||||
| Positive lung US | 9 (90) | 9 (47.4) | 18 (62.1) | 10 (1.1-95.2) | Sensitivity: 0.90 (0.60-0.98); specificity: 0.53 (0.32-0.73); PPV: 0.50 (0.29-0.71); NPV: 0.91 (0.62-0.98); positive LR: 1.90 (1.13-3.19); negative LR: 0.19 (0.03-1.28) |
| Negative lung US | 1 (10) | 10 (52.6) | 11 (37.9) | [.04] | |
| Total | 10 (100) | 19 (100) | 29 (100) | ||
LR = likelihood ratio; NPV = negative predictive value; OR = odds ratio; PPV = positive predictive value; US = ultrasound.
↵a In the 2 cases where a cell contained a 0 value, the OR was calculated by imputing 0.5 for that cell.