Table 1.
Baseline characteristics of data sets.
| Characteristics | Development | Internal validation | External validation (MIMIC-IIIa) | ||||||||||
|
|
Case (n=3060) | Control (n=6529) | Case (n=756) | Control (n=2064) | Case (n=272) | Control (n=1789) | |||||||
| Age (years), mean (SD) | 65.4 (14.4) | 61.1 (13.3) | 65.3 (14.7) | 59.7 (14.0) | 82.5 (59.7) | 73.7 (52.3) | |||||||
| Sex (male), n (%) | 1994 (65.2) | 4227 (64.7) | 466 (61.6) | 1190 (57.7) | 137 (50.4) | 925 (51.7) | |||||||
| Admission category, n (%) | |||||||||||||
|
|
Medical | 1431 (46.8) | 1639 (25.1) | 293 (38.8) | 344 (16.7) | 151 (55.5) | 1,141(63.8) | ||||||
|
|
Surgical | 1629 (53.2) | 4890 (74.9) | 1,720 (83.3) | 463 (61.2) | 121 (44.5) | 648(36.2) | ||||||
| Reason for ICUb admission, n (%) | |||||||||||||
|
|
Respiratory | 692 (22.6) | 374 (5.7) | 166 (22.0) | 71 (3.4) | 34 (12.5) | 247 (13.8) | ||||||
|
|
Cardiovascular | 480 (15.7) | 1166(17.9) | 105 (13.9) | 283 (13.7) | 73 (26.8) | 561 (31.4) | ||||||
|
|
Gastrointestinal | 145 (4.7) | 139 (2.1) | 28 (3.7) | 25 (1.2) | 55 (20.2) | 379 (21.2) | ||||||
|
|
Neurology | 102 (3.3) | 115 (1.8) | 46 (6.1) | 174 (8.4) | 57 (21.0) | 270 (15.1) | ||||||
|
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Peri-operation | 1168 (38.2) | 4278 (65.5) | 320 (42.3) | 1448 (70.2) | 14 (5.1) | 81 (4.5) | ||||||
|
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Nephrology | 83 (2.7) | 78 (1.2) | 17 (2.2) | 17 (0.8) | 4 (1.5) | 54 (3.0) | ||||||
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Metabolic | 15 (0.5) | 6 (0.1) | 1 (0.1) | 0 (0.0) | 5 (1.8) | 85 (4.8) | ||||||
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Hematology | 15 (0.5) | 22 (0.3) | 4 (0.5) | 6 (0.3) | 5 (1.8) | 33 (1.8) | ||||||
|
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Trauma | 10 (0.3) | 10 (0.2) | 2 (0.3) | 0 (0.0) | 25 (9.2) | 79 (4.4) | ||||||
|
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Others | 350 (11.4) | 341 (5.2) | 67 (8.9) | 40 (1.9) | — | — | ||||||
| Initial SOFAc, mean (SD) | 7.1 (3.6) | 3.2 (2.7) | 7.0 (3.7) | 2.8 (2.5) | 5.4 (3.3) | 3.1 (2.4) | |||||||
| Vasopressord, n (%) | 1,145 (37.4) | 793 (12.1) | 292 (38.6) | 175 (8.5) | 38 (14.0) | 71 (4.0) | |||||||
| Invasive mechanical ventilator, n (%) | 1,900 (62.1) | 1,165 (17.8) | 456 (60.3) | 344 (16.7) | 19 (7.0) | 73 (4.1) | |||||||
| CCIe, mean (SD) | 0.9 (2.2) | 0.3 (1.3) | 1.1 (2.5) | 0.4 (1.4) | 3.2 (1.8) | 2.8 (1.8) | |||||||
| Comorbidity, n (%) | |||||||||||||
|
|
Heart disease | 149 (4.9) | 123 (1.9) | 17 (2.2) | 20 (1.0) | 33 (12.1) | 232 (13.0) | ||||||
|
|
Stroke | 98 (3.2) | 33 (0.5) | 29 (3.8) | 24 (1.2) | 16 (5.9) | 57 (3.2) | ||||||
|
|
Malignancy | 434 (14.2) | 319 (4.9) | 80 (10.6) | 60 (2.9) | 5 (1.8) | 12 (0.7) | ||||||
|
|
Renal failure | 71 (2.3) | 99 (1.5) | 16 (2.1) | 26 (1.3) | 17 (12.1) | 106 (12.7) | ||||||
|
|
Liver disease | 146 (4.8) | 92 (1.4) | 23 (3.0) | 15 (0.7) | 38 (14.0) | 168 (9.4) | ||||||
|
|
Dementia | 55 (1.8) | 9 (0.1) | 17 (2.2) | 6 (0.3) | — | — | ||||||
| Vital signs, mean (SD) | |||||||||||||
|
|
Systolic BPf | 125.8 (24.7) | 127.4 (21.7) | 128.6 (26.4) | 130.8 (22.2) | 118.5 (25.0) | 119.5 (22.7) | ||||||
|
|
Diastolic BP | 71.6 (15.5) | 74.3 (14.1) | 72.3 (17.9) | 73.3 (14.7) | 63.3 (15.9) | 63.9 (15.4) | ||||||
|
|
Heart rate | 85.4 (20.7) | 80.7 (16.6) | 84.5 (20.5) | 80.6 (16.1) | 89.9 (20.3) | 85.8 (19.4) | ||||||
|
|
Respiratory rate | 19.3 (3.9) | 18.3 (2.5) | 18.8 (3.7) | 17.7 (2.5) | 20.5 (6.5) | 19.2 (5.4) | ||||||
|
|
SpO2g | 96.1 (5.5) | 96.9 (4.3) | 96.5 (4.0) | 97.4 (2.1) | 95.9 (3.6) | 96.2 (3.1) | ||||||
|
|
Body temperature (°C) | 36.7 (0.8) | 36.6 (0.5) | 36.7 (0.8) | 36.6 (0.4) | 36.8 (0.7) | 36.8 (0.6) | ||||||
| ABGAh, mean (SD) | |||||||||||||
|
|
pH | 7.4 (0.1) | 7.4 (0.1) | 7.4 (0.1) | 7.4 (0.1) | 7.4 (0.1) | 7.4 (0.1) | ||||||
|
|
PaCO2 | 35.5 (14.1) | 36.2 (7.5) | 35.3 (11.3) | 36.4 (6.2) | 42.0 (12.4) | 41.1 (12.1) | ||||||
|
|
PaO2 | 119.8 (83.4) | 184.4 (110.8) | 122.0 (82.5) | 190.4 (104.8) | 131.9 (106.0) | 125.0 (67.9) | ||||||
|
|
HCO3 | 22.0 (5.5) | 23.1 (3.6) | 22.0 (5.3) | 23.5 (2.9) | 24.1 (5.4) | 24.2 (4.7) | ||||||
aMIMIC-III: Medical Information Mart for Intensive Care III.
bICU: intensive care unit.
cSOFA: sequential organ failure assessment.
dVasopressor: epinephrine, norepinephrine, dobutamine, dopamine, vasopressin.
eCCI: Charlson Comorbidity Index.
fBP: blood pressure.
gSpO2: peripheral capillary oxygen saturation.
hABGA: arterial blood gas analysis.