Table 1 Comparison of derivation and validation cohorts
| Â | Total | Derivation | Validation | Â |
|---|---|---|---|---|
Variable* | (n = 4,361) | (n = 2,000) | (n = 2,361) | p-value |
Demographics | Â | Â | Â | Â |
Median age | 56.0 (41.0, 71.0) | 56.0 (42.0, 71.0) | 56.0 (41.0, 71.0) | 0.596 |
Male, no. (%) | 2,422 (55.5%) | 1,104 (55.2%) | 1,318 (55.8%) | 0.680 |
Caucasian, no. (%), n = 4,220 | 2,608 (61.8%) | 1,193 (61.6%) | 1,415 (62.0%) | 0.765 |
Admission source, no. (%) n = 4,311 |  |  |  | 0.131 |
Home | 3,331 (77.3%) | 1,557 (78.8%) | 1,774 (76.0%) | Â |
Nursing facility | 338 (7.8%) | 151 (7.6%) | 187 (8.0%) | Â |
Outside ED | 440 (10.2%) | 183 (9.3%) | 257 (11.0%) | Â |
Other | 202 (4.7%) | 85 (4.3%) | 117 (5.0%) | Â |
APACHE II | 10.0 (6.0, 15.0) | 10.0 (6.0, 15.0) | 10.0 (5.0, 15.0) | 0.770 |
Predisposing conditions | Â | Â | Â | Â |
Shock | 395 (9.1%) | 180 (9.0%) | 215 (9.1%) | 0.903 |
Aspiration | 210 (4.8%) | 92 (4.6%) | 118 (5.0%) | 0.541 |
Sepsis | 1,806 (41.4%) | 856 (72.8%) | 950 (70.2%) | 0.087 |
Pancreatitis | 323 (7.4%) | 140 (7.0%) | 183 (7.8%) | 0.345 |
Pneumonia | 1,227 (28.1%) | 568 (28.4%) | 659 (27.9%) | 0.721 |
High-risk trauma | Â | Â | Â | Â |
Traumatic brain injury | 490 (11.2%) | 214 (10.7%) | 276 (11.7%) | 0.302 |
Smoke inhalation | 27 (0.6%) | 10 (0.5%) | 17 (0.7%) | 0.356 |
Near drowning | 3 (0.1%) | 2 (0.1%) | 1 (0.0%) | 0.597 |
Lung contusion | 188 (4.3%) | 87 (4.4%) | 101 (4.3%) | 0.907 |
Multiple fractures | 330 (7.6%) | 141 (7.1%) | 189 (8.0%) | 0.235 |
High-risk surgery | Â | Â | Â | Â |
Thoracic (noncardiac) | 5 (0.1%) | 3 (0.2%) | 2 (0.2%) | 0.526 |
Orthopedic spine | 17 (0.4%) | 6 (0.3%) | 11 (0.5%) | 0.381 |
Acute abdomen | 295 (6.8%) | 133 (6.7%) | 162 (6.9%) | 0.782 |
Cardiac surgery | 20 (0.5%) | 6 (0.3%) | 14 (0.6%) | 0.154 |
Aortic vascular | 14 (0.3%) | 5 (0.3%) | 9 (0.4%) | 0.445 |
Risk modifiers | Â | Â | Â | Â |
Alcohol abuse | 421 (9.7%) | 191 (9.6%) | 230 (9.7%) | 0.831 |
Obesity | 1,020 (29.1%) | 456 (28.5%) | 564 (29.6%) | 0.451 |
Chemotherapy | 158 (3.6%) | 82 (4.1%) | 76 (3.2%) | 0.121 |
Diabetes mellitus | 1,042 (23.9%) | 485 (24.3%) | 557 (23.6%) | 0.612 |
Smoking (n = 4019) |  |  |  | 0.892 |
None | 2,060 (51.3%) | 932 (50.9%) | 1,128 (51.6%) | Â |
Former | 888 (22.1%) | 408 (22.3%) | 480 (22.0%) | Â |
Active | 1,071 (26.7%) | 493 (26.9%) | 578 (26.4%) | Â |
Emergency surgery | 339 (7.7%) | 154 (7.7%) | 185 (7.8%) | 0.868 |
RR | 20.0 (18.0, 24.0) | 20.0 (18.0, 24.0) | 20.0 (18.0, 24.0) | 0.658 |
Tachypnea | 315 (7.6%) | 145 (7.6%) | 170 (7.6%) | 0.948 |
SpO2 | 95.6 (95.4, 95.7) | 95.2 (95.2, 95.7) | 95.7 (95.5, 95.9) | 0.068 |
SpO2 > 95% | 2,662 (62.3%) | 1,203 (61.4%) | 1,459 (63.1%) | 0.254 |
FiO2 | 0.2 (0.2, 0.3) | 0.2 (0.2, 0.3) | 0.2 (0.2, 0.3) | 0.561 |
FiO2 > 0.35, no. (%) | 841 (19.3%) | 381 (19.1%) | 452 (19.1%) | 0.937 |
Albumin level | 3.5 (2.9, 4.0) | 3.5 (3.0, 4.0) | 3.5 (2.9, 4.0) | 0.068 |
Hypoalbuminemia | 945 (47.1%) | 414 (45.4%) | 531 (48.5%) | 0.167 |
pH median | 7.4 (7.3, 7.4) | 7.4 (7.3, 7.4) | 7.4 (7.3, 7.4) | 0.632 |
Acidosis (pH <7.35) | 476 (45.9%) | 206 (43.6%) | 270 (47.8%) | 0.173 |
Outcome | Â | Â | Â | Â |
ALI/ARDS | 303 (7.0%) | 127 (6.4%) | 176 (7.5%) | 0.153 |