Table 2 Patient baseline laboratory and x-ray findings, Pneumonia Severity Index and clinical outcomes within 28 days
Characteristics | Derivation sample | Validation sample | P value |
|---|---|---|---|
(n = 4593) | (n = 1967) | ||
Laboratory and x-ray findings | |||
Arterial pH, median (IQR) | 7.45 (7.41 to 7.47) | 7.44 (7.41 to 7.47) | 0.59 |
Arterial partial pressure of oxygen, median (IQR), mmHg | 63 (55 to 74) | 64 (55 to 73) | 0.62 |
BUN, median (IQR), mEq/L | 6 (4 to 9) | 6 (4 to 9) | 0.81 |
Sodium, median (IQR), mEq/L | 137 (134 to 139) | 137 (134 to 139) | 0.63 |
Glucose, median (IQR), % | 7 (6 to 9) | 7 (6 to 9) | 0.97 |
Multilobar infiltrates | 39 (35 to 42) | 39 (36 to 42) | 0.48 |
WBC, median (IQR), G/L | 11.7 (8.5 to 15.8) | 11.2 (8.1 to 15.3) | 0.04 |
Multilobar infiltrates, n (%) | 0.80 | ||
Pleural effusion, n (%) | 503 (10.9) | 206 (10.5) | 0.57 |
Pneumonia Severity Index, n (%) | 0.80 | ||
Class I | 1259 (27.4) | 538 (27.3) | |
Class II | 1075 (23.4) | 479 (24.3) | |
Class III | 877 (19.1) | 372 (18.9) | |
Class IV | 1104 (24.0) | 451 (22.9) | |
Class V | 278 (6.0) | 127 (6.5) | |
Outcomes | |||
ICU admission ≤ 3 days, n (%) | 201 (4.4) | 102 (5.2) | 0.15 |
3-day mortality, n (%) | 41 (0.9) | 12 (0.6) | 0.24 |
28-day ICU admissions, n (%) | 259 (5.6) | 119 (6.0) | 0.51 |
28-day mortality, n (%) | 184 (4.0) | 78 (4.0) | 0.94 |