Table 1 Baseline characteristics of the study cohort (grouped by training and testing sets).
From: Machine learning model to predict sepsis in ICU patients with intracerebral hemorrhage
Variable | n (%) or median (Interquartile range) | P value | ||
|---|---|---|---|---|
Total patients (n = 2214) | Training set (n = 1550) | Testing set (n = 664) | ||
Follow-up time until sepsis (days) | 1.2 [0.3, 2.8] | 1.2 [0.3, 2.8] | 1.2 [0.4, 2.8] | > 0.900 |
Mortality | 569.0 (25.7) | 418.0 (27.0) | 151.0 (22.7) | 0.037 |
LOS | 7.1 [3.7, 13.9] | 7.5 [3.8, 14.0] | 6.7 [3.7, 13.5] | 0.300 |
Sepsis | 813 (36.7) | 569 (36.7) | 244 (36.7) | 1.000 |
Age, years | ||||
<40 | 121 (5.5) | 86 (5.5) | 35 (5.3) | 0.866 |
40–64 | 751 (33.9) | 530 (34.2) | 221 (33.3) | |
≥65 | 1342 (60.6) | 934 (60.3) | 408 (61.4) | |
Gender, Male | 1184 (53.5) | 830 (53.5) | 354 (53.3) | 0.956 |
Race | ||||
Asian | 80 (3.6) | 57 (3.7) | 23 (3.5) | 0.290 |
Black | 200 (9.0) | 146 (9.4) | 54 (8.1) | |
Other | 540 (24.4) | 391 (25.2) | 149 (22.4) | |
White | 1394 (63.0) | 956 (61.7) | 438 (66.0) | |
BMI, kg/m² | ||||
< 18.5 | 29 (1.3) | 20 (1.3) | 9 (1.4) | 0.826 |
18.5–24.9 | 242 (10.9) | 170 (11.0) | 72 (10.8) | |
25-29.9 | 284 (12.8) | 194 (12.5) | 90 (13.6) | |
≥30 | 266 (12.0) | 180 (11.6) | 86 (13.0) | |
Missing | 1393 (62.9) | 986 (63.6) | 407 (61.3) | |
Comorbidities | ||||
Acute pneumonia | 233 (10.5) | 169 (10.9) | 64 (9.6) | 0.416 |
Chronic pulmonary | 274 (12.4) | 199 (12.8) | 75 (11.3) | 0.347 |
Diabetes | 538 (24.3) | 389 (25.1) | 149 (22.4) | 0.200 |
Fluid electrolyte disorders | 753 (34.0) | 520 (33.5) | 233 (35.1) | 0.514 |
Heart disease | 1023 (46.2) | 713 (46.0) | 310 (46.7) | 0.802 |
Hypertension | 1378 (62.2) | 979 (63.2) | 399 (60.1) | 0.188 |
Liver disease | 120 (5.4) | 93 (6.0) | 27 (4.1) | 0.082 |
Non-infectious colon disease | 17 (0.8) | 13 (0.8) | 4 (0.6) | 0.750 |
Obesity | 133 (6.0) | 90 (5.8) | 43 (6.5) | 0.610 |
Renal failure | 465 (21.0) | 320 (20.6) | 145 (21.8) | 0.566 |
Interventions | ||||
CRRT | 4 (0.2) | 2 (0.1) | 2 (0.3) | 0.743 |
ICP monitoring | 94 (4.2) | 66 (4.3) | 28 (4.2) | 1.000 |
PICC | 125 (5.6) | 88 (5.7) | 37 (5.6) | 1.000 |
Invasive ventilation | 532 (24.0) | 374 (24.1) | 158 (23.8) | 0.909 |
Supplemental oxygen | 735 (33.2) | 509 (32.8) | 226 (34.0) | 0.618 |
Craniocerebral operations | ||||
Craniotomy | 24 (1.1) | 16 (1.0) | 8 (1.2) | 0.414 |
MIS | 41 (1.9) | 25 (1.6) | 16 (2.4) | |
None | 2149 (97.1) | 1509 (97.4) | 640 (96.4) | |
First laboratory test | ||||
Anion gap (mmol/l) | 14.57 [13.00, 16.00] | 14.55 [13.00, 16.00] | 14.61 [13.00, 16.00] | 0.646 |
Bicarbonate (mg/dl) | 24.10 [22.00, 25.48] | 24.09 [22.00, 25.36] | 24.14 [22.00, 25.88] | 0.861 |
BUN (mg/dl) | 16.00 [13.00, 19.00] | 16.00 [13.00, 19.00] | 16.00 [13.00, 19.00] | 0.773 |
Chloride (mmol/l) | 103.24 [101.77, 105.16] | 103.40 [102.00, 105.13] | 103.00 [101.00, 105.25] | 0.136 |
Creatinine (mg/dl) | 0.89 [0.70, 1.00] | 0.88 [0.70, 1.00] | 0.89 [0.80, 1.00] | 0.365 |
Hematocrit | 36.46 [34.30, 39.50] | 36.44 [34.20, 39.40] | 36.50 [34.30, 39.60] | 0.827 |
Hemoglobin (g/dl) | 12.20 [11.40, 13.30] | 12.20 [11.30, 13.30] | 12.22 [11.50, 13.33] | 0.356 |
Platelet (×109/l) | 212.00 [177.00, 242.00] | 213.00 [178.00, 243.00] | 209.13 [176.75, 242.00] | 0.319 |
Potassium (mmol/l) | 3.90 [3.70, 4.20] | 3.90 [3.70, 4.12] | 3.90 [3.70, 4.30] | 0.247 |
WBC (×109/l) | 10.23 [8.40, 12.10] | 10.25 [8.40, 12.10] | 10.16 [8.40, 12.00] | 0.534 |
Lymphocyte percentage | ||||
< 18 | 264 (11.9) | 193 (12.5) | 71 (10.7) | 0.625 |
18–42 | 78 (3.5) | 52 (3.4) | 26 (3.9) | |
> 42 | 4 (0.2) | 3 (0.2) | 1 (0.2) | |
Missing | 1868 (84.4) | 1302 (84.0) | 566 (85.2) | |
Monocyte percentage | ||||
< 2 | 17 (0.8) | 15 (1.0) | 2 (0.3) | 0.257 |
2–11 | 306 (13.8) | 219 (14.1) | 87 (13.1) | |
> 11 | 23 (1.0) | 14 (0.9) | 9 (1.4) | |
Missing | 1868 (84.4) | 1302 (84.0) | 566 (85.2) | |
Neutrophil percentage | ||||
< 50 | 11 (0.5) | 10 (0.6) | 1 (0.2) | 0.302 |
50–70 | 64 (2.9) | 42 (2.7) | 22 (3.3) | |
> 70 | 271 (12.2) | 196 (12.6) | 75 (11.3) | |
Missing | 1868 (84.4) | 1302 (84.0) | 566 (85.2) | |
PT, sec | ||||
< 10.4 | 27 (1.2) | 17 (1.1) | 10 (1.5) | 0.852 |
10.4–13.4 | 982 (44.4) | 685 (44.2) | 297 (44.7) | |
> 13.4 | 494 (22.3) | 346 (22.3) | 148 (22.3) | |
Missing | 711 (32.1) | 502 (32.4) | 209 (31.5) | |
Sodium, mmol/l | ||||
< 133 | 34 (1.5) | 24 (1.5) | 10 (1.5) | 0.353 |
133–145 | 86 (3.9) | 53 (3.4) | 33 (5.0) | 0.353 |
> 145 | 13 (0.6) | 10 (0.6) | 3 (0.5) | 0.353 |
Missing | 2081 (94.0) | 1463 (94.4) | 618 (93.1) | 0.353 |
Heart rate (beats per minute) | 80.00 [70.00, 91.75] | 80.00 [70.00, 91.00] | 80.00 [69.00, 92.25] | 0.980 |
Respiratory rate (inspirations per minute) | 18.00 [15.00, 21.00] | 18.00 [15.00, 21.00] | 18.00 [15.00, 21.00] | 0.702 |
SBP, mmHg | ||||
< 90 | 4 (0.2) | 4 (0.3) | 0 (0.0) | 0.359 |
90–99 | 30 (1.4) | 19 (1.2) | 11 (1.7) | |
100–109 | 94 (4.2) | 63 (4.1) | 31 (4.7) | |
≥ 110 | 892 (40.3) | 613 (39.5) | 279 (42.0) | |
Missing | 1194 (53.9) | 851 (54.9) | 343 (51.7) | |
DBP, mmHg | ||||
< 140 | 1019 (46.0) | 699 (45.1) | 320 (48.2) | 0.122 |
140–159 | 1 (0.0) | 0 (0.0) | 1 (0.2) | |
Missing | 1194 (53.9) | 851 (54.9) | 343 (51.7) | |
GCS score | 14.00 [11.00, 15.00] | 14.00 [11.00, 15.00] | 14.00 [11.00, 15.00] | 0.892 |
SOFA score | 1.00 [0.00, 2.00] | 1.00 [0.00, 2.00] | 0.50 [0.00, 1.00] | 0.627 |
