Table 2.
Comparison of baseline CXR findings in patients with or without on-treatment pneumonia (independent blinded radiologist review)
| CXR finding, n (%) | Pneumonia group (n=179)
|
Non-pneumonia group (n=50)
|
P-valueb | LR+c | LR−d | Diagnostic ORe(95% CI) | ||
|---|---|---|---|---|---|---|---|---|
| Yes | No | Yes | No | |||||
| ≥1 CXR findinga | 179 (100) | 0 | 50 (100) | 0 | – | – | – | – |
| Abnormal cardio/thoracic ratio measurement | 53 (30)f | 126 (70)g | 12 (24)f | 38 (76)g | 0.437 | 1.23 | 0.93 | 1.33 (0.65, 2.75) |
| Atelectasis or other evidence of volume loss | 31 (17) | 148 (83) | 9 (18) | 41 (82) | 0.911 | 0.96 | 1.01 | 0.95 (0.42, 2.16) |
| Basilar lines of COPD | 11 (6) | 168 (94) | 5 (10) | 45 (90) | 0.344 | 0.61 | 1.04 | 0.59 (0.19, 1.78) |
| Blurring or loss of diaphragmatic shadow | 21 (12) | 158 (88) | 5 (10) | 45 (90) | 0.733 | 1.17 | 0.98 | 1.20 (0.43, 3.35) |
| Calcified pleural plaque over the diaphragm or mid-chest pleural thickeningh | 5 (8) | 60 (92) | 0 | 15 (100) | 0.578 | 2.67 | 0.95 | 2.82 (0.15, 53.76) |
| Elevation of hemi-diaphragm (indirect sign of volume loss [any lobe]) | 22 (12) | 157 (88) | 1 (2) | 49 (98) | 0.033 | 6.15 | 0.89 | 6.87 (0.90, 52.26) |
| Evidence of hiatal herniah | 2 (3) | 63 (97) | 2 (13) | 13 (87) | 0.158 | 0.23 | 1.12 | 0.21 (0.03, 1.60) |
| Focal/diffuse reticular-nodular or “ground glass” shadows | 11 (6) | 168 (94) | 5 (10) | 45 (90) | 0.344 | 0.61 | 1.04 | 0.59 (0.19, 1.78) |
| Hyperinflated chest | 172 (96) | 7 (4) | 47 (94) | 3 (6) | 0.458 | 1.02 | 0.65 | 1.57 (0.39, 6.30) |
| Indirect signs of upper lobe volume loss (elevation of the right hilum) | 20 (11) | 159 (89) | 11 (22) | 39 (78) | 0.048 | 0.51 | 1.14 | 0.45 (0.20, 1.01) |
| Large cardiac silhouette | 26 (15) | 153 (85) | 9 (18) | 41 (82) | 0.546 | 0.81 | 1.04 | 0.77 (0.34, 1.78) |
| Large/prominent pulmonary artery shadow | 68 (38) | 111 (62) | 12 (24) | 38 (76) | 0.067 | 1.58 | 0.82 | 1.94 (0.95, 3.97) |
| Narrow cardiac silhouette | 28 (16) | 151 (84) | 3 (6) | 47 (94) | 0.101 | 2.61 | 0.90 | 2.91 (0.85, 9.99) |
| Normal heart size in a hyperinflated chest (normal cardiac silhouette) | 126 (70) | 53 (30) | 38 (76) | 12 (24) | 0.437 | 0.93 | 1.23 | 0.75 (0.36, 1.55) |
| Pleural thickening (any pleural change, apical, or basal can reflect sub pulmonic effusion or diaphragm shadow being indistinct) | 71 (40) | 108 (60) | 20 (40) | 30 (60) | 0.966 | 0.99 | 1.01 | 0.99 (0.52, 1.87) |
| Pleural thickening at apices | 18 (10) | 161 (90) | 6 (12) | 44 (88) | 0.692 | 0.84 | 1.02 | 0.82 (0.31, 2.19) |
| Pleural thickening at bases (including costophrenic angle blunting) | 25 (14) | 154 (86) | 7 (14) | 43 (86) | 0.995 | 1.00 | 1.00 | 1.00 (0.40, 2.46) |
| Signs of bronchiectasis (not common few instances outside upper lobes) | 7 (4) | 172 (96) | 2 (4) | 48 (96) | 1.000 | 0.98 | 1.00 | 0.98 (0.20, 4.86) |
| Signs of congestive heart failure in addition to large heart | 6 (3) | 173 (97) | 1 (2) | 49 (98) | 1.000 | 1.68 | 0.99 | 1.70 (0.20, 14.45) |
| Thick tracheal-esophageal stripe on lateral view | 7 (4) | 172 (96) | 0 | 50 (100) | 0.352 | 4.25 | 0.97 | 4.39 (0.25, 78.22) |
| Vascular calcification, either coronary, carotid, or within the aortic shadow | 74 (41) | 105 (59) | 18 (36) | 32 (64) | 0.496 | 1.15 | 0.92 | 1.25 (0.65, 2.40) |
Notes: Statistically significant P-values (P≤0.05) are shown in bold. Gray shading indicates CXR findings with a diagnostic OR of >2.
Includes patients with at least one CXR finding, excluding the finding of hyperinflated chest.
Chi-square test or Fisher’s exact test (the latter test was used if any values <5).
LR+ defined as the ratio of the likelihood of observing the CXR finding in a patient who developed on-treatment pneumonia than in a patient who did not develop on-treatment pneumonia.
LR− defined as the ratio of the likelihood of not observing the CXR finding in a patient who developed on-treatment pneumonia than in a patient who did not develop on-treatment pneumonia.
Diagnostic OR defined as the ratio of the odds of being a true positive to the odds of being a false positive. An OR of >1 indicates an association between the CXR finding and subsequent development of pneumonia, and <1 indicates an association between the CXR finding and no subsequent development of pneumonia.
Actual cardio/thoracic ratio measurement ratio was abnormal (<0.5 or >0.5).
Actual cardio/thoracic ratio measurement was normal (0.5).
Data missing for 114 patients in the pneumonia group and 35 patients in the non-pneumonia group; percentages are based on patients with available data.
Abbreviations: CXR, chest X-ray; LR+, positive likelihood ratio; LR−, negative likelihood ratio; OR, odds ratio.