Table 1 The patients’ characteristics of survival group and death group in the training set

Age, years, Mean ± SD

68.02 ± 15.47

64.06 ± 16.12

71.04 ± 14.24

t = -8.40

 < 0.001

Gender, n (%)

χ² = 4.202

0.040

 Female

586 (42.22)

272 (45.33)

314 (39.85)

 Male

802 (57.78)

328 (54.67)

474 (60.15)

Marital status, n (%)

χ² = 0.458

0.499

 Married

668 (48.13)

295 (49.17)

373 (47.34)

 Not married

720 (51.87)

305 (50.83)

415 (52.66)

Ethnicity, n (%)

χ² = 14.338

0.002

 White

1128 (81.27)

464 (77.33)

664 (84.26)

 Asian

43 (3.10)

28 (4.67)

15 (1.90)

 Black

142 (10.23)

72 (12.00)

70 (8.88)

 Hispanic

75 (5.40)

36 (6.00)

39 (4.95)

ICU type, n (%)

χ² = 5.795

0.215

 CCU

140 (10.09)

53 (8.83)

87 (11.04)

 CSRU

56 (4.03)

18 (3.00)

38 (4.82)

 MICU

937 (67.51)

421 (70.17)

516 (65.48)

 SICU

176 (12.68)

76 (12.67)

100 (12.69)

 TSICU

79 (5.69)

32 (5.33)

47 (5.96)

Length of stay, days, M (Q₁, Q₃)

5.67 (2.81, 12.73)

5.02 (2.59, 12.17)

6.07 (2.90, 12.80)

Z = -1.573

0.116

Respiratory rate, times/min, Mean ± SD

21.53 ± 6.62

21.56 ± 6.64

21.51 ± 6.60

t = 0.15

0.881

Temperature, ℃, Mean ± SD

36.72 ± 2.50

36.88 ± 3.54

36.59 ± 1.22

t = 1.90

0.058

Heart rate, times/min, Mean ± SD

97.36 ± 21.79

98.76 ± 21.32

96.29 ± 22.09

t = 2.09

0.037

SBP, mmHg, Mean ± SD

115.05 ± 25.39

115.60 ± 24.79

114.63 ± 25.84

t = 0.71

0.479

DBP, mmHg, Mean ± SD

61.62 ± 18.60

63.55 ± 19.27

60.15 ± 17.94

t = 3.39

 < 0.001

MAP, mmHg, Mean ± SD

76.36 ± 19.21

77.16 ± 19.75

75.76 ± 18.78

t = 1.34

0.180

SPO₂, Mean ± SD

95.82 ± 7.35

95.98 ± 7.30

95.70 ± 7.40

t = 0.71

0.478

WBC, K/uL, M (Q₁, Q₃)

11.90 (7.70, 17.40)

12.50 (8.20, 18.10)

11.70 (7.40, 16.80)

Z = 1.925

0.054

RBC, m/uL, Mean ± SD

3.75 ± 0.77

3.87 ± 0.76

3.66 ± 0.77

t = 5.26

 < 0.001

Sodium, mEq/L, Mean ± SD

137.59 ± 6.55

137.64 ± 6.45

137.54 ± 6.62

t = 0.29

0.772

Potassium, mEq/L, Mean ± SD

4.43 ± 1.00

4.26 ± 0.95

4.56 ± 1.02

t = -5.57

 < .001

Phosphate, mg/dL, M (Q₁, Q₃)

3.60 (2.80, 4.60)

3.30 (2.60, 4.30)

3.80 (3.00, 4.90)

Z = -6.595

 < 0.001

Calcium, mg/dL, Mean ± SD

8.21 ± 1.06

8.08 ± 1.05

8.31 ± 1.06

t = -4.03

 < 0.001

PLT, K/uL, M (Q₁, Q₃)

210.00 (133.00, 303.00)

215.00 (145.50, 292.00)

207.50 (123.00, 311.00)

Z = 1.093

0.274

pH, Mean ± SD

7.34 ± 0.12

7.33 ± 0.12

7.34 ± 0.12

t = -1.31

0.191

Lactate, mmol/L, M (Q₁, Q₃)

2.30 (1.50, 3.80)

2.20 (1.50, 3.80)

2.30 (1.50, 3.70)

Z = -0.597

0.550

Magnesium, mg/dL, Mean ± SD

1.94 ± 0.51

1.87 ± 0.48

2.00 ± 0.52

t = -4.75

 < 0.001

Glucose, mg/dL, M (Q₁, Q₃)

132.00 (106.00, 177.00)

134.00 (108.00, 182.50)

131.00 (105.00, 174.00)

Z = 1.747

0.081

Creatinine, mg/dL, M (Q₁, Q₃)

1.50 (1.00, 2.50)

1.40 (1.00, 2.25)

1.60 (1.00, 2.70)

Z = -2.998

0.003

BUN, mg/dL, M (Q₁, Q₃)

31.50 (20.00, 51.00)

27.50 (18.00, 44.00)

35.00 (22.00, 57.00)

Z = -5.852

 < 0.001

Bicarbonate, mEq/L, Mean ± SD

22.56 ± 5.56

22.28 ± 5.28

22.78 ± 5.75

t = -1.68

0.093

Albumin, Mean ± SD

2.90 ± 0.65

2.97 ± 0.67

2.85 ± 0.62

t = 3.37

 < 0.001

TBIL, mg/dL, M (Q₁, Q₃)

0.70 (0.40, 1.50)

0.60 (0.40, 1.30)

0.70 (0.40, 1.70)

Z = -2.038

0.042

Hematocrit, %, Mean ± SD

33.99 ± 6.51

34.94 ± 6.50

33.26 ± 6.43

t = 4.78

 < 0.001

Hemoglobin, g/dL, Mean ± SD

11.25 ± 2.21

11.64 ± 2.22

10.96 ± 2.16

t = 5.72

 < 0.001

MCHC, Mean ± SD

33.12 ± 1.66

33.31 ± 1.67

32.97 ± 1.64

t = 3.73

 < 0.001

ALP, M (Q₁, Q₃)

99.00 (70.00, 155.00)

91.00 (65.00, 135.00)

103.00 (73.00, 168.00)

Z = -4.354

 < 0.001

ALT, U/L, M (Q₁, Q₃)

30.00 (17.00, 64.00)

30.50 (18.00, 64.10)

30.00 (17.00, 64.00)

Z = 0.373

0.709

AST, U/L, M (Q₁, Q₃)

43.00 (25.00, 100.00)

43.00 (25.00, 86.00)

43.00 (26.00, 110.00)

Z = -0.878

0.380

LDH, U/L, M (Q₁, Q₃)

281.00 (213.00, 426.50)

258.50 (206.00, 371.00)

300.00 (219.00, 486.50)

Z = -4.829

 < 0.001

CK, U/L, M (Q₁, Q₃)

113.00 (47.00, 285.00)

134.50 (60.00, 329.50)

97.50 (40.00, 259.00)

Z = 4.279

 < 0.001

CK-MB, U/L, M (Q₁, Q₃)

4.00 (3.00, 8.00)

4.00 (2.00, 8.00)

4.61 (3.00, 8.50)

Z = -2.308

0.021

PO₂, M (Q₁, Q₃)

98.00 (68.00, 178.20)

100.00 (69.00, 184.50)

95.20 (67.00, 174.50)

Z = 0.605

0.545

PCO₂, M (Q₁, Q₃)

39.00 (33.00, 47.00)

39.30 (34.00, 47.00)

39.00 (33.00, 47.00)

Z = 0.909

0.363

Congestive heart failure, n (%)

χ² = 4.584

0.032

 No

727 (52.38)

334 (55.67)

393 (49.87)

 Yes

661 (47.62)

266 (44.33)

395 (50.13)

Malignant tumor, n (%)

χ² = 12.904

 < 0.001

 No

1022 (73.63)

471 (78.50)

551 (69.92)

 Yes

366 (26.37)

129 (21.50)

237 (30.08)

Atrial fibrillation, n (%)

χ² = 13.799

 < 0.001

 No

796 (57.35)

378 (63.00)

418 (53.05)

 Yes

592 (42.65)

222 (37.00)

370 (46.95)

Respiratory failure, n (%)

χ² = 20.654

 < 0.001

 No

607 (43.73)

304 (50.67)

303 (38.45)

 Yes

781 (56.27)

296 (49.33)

485 (61.55)

Septic shock, n (%)

χ² = 1.338

0.247

 No

637 (45.89)

286 (47.67)

351 (44.54)

 Yes

751 (54.11)

314 (52.33)

437 (55.46)

Elixhauser score, M (Q₁, Q₃)

24.00 (14.00, 34.00)

18.00 (9.00, 29.00)

27.00 (18.00, 36.00)

Z = -10.266

 < 0.001

SOFA total score, M (Q₁, Q₃)

7.00 (5.00, 10.00)

7.00 (4.00, 10.00)

8.00 (5.00, 11.00)

Z = -5.016

 < 0.001

SAPS II, M (Q₁, Q₃)

47.00 (37.00, 57.00)

41.00 (33.00, 51.00)

50.00 (41.00, 61.00)

Z = -11.426

 < 0.001

RRT, n (%)

χ² = 7.715

0.005

 No

1243 (89.55)

553 (92.17)

690 (87.56)

 Yes

145 (10.45)

47 (7.83)

98 (12.44)

Ventilation, n (%)

χ² = 11.529

 < 0.001

 No

457 (32.93)

227 (37.83)

230 (29.19)

 Yes

931 (67.07)

373 (62.17)

558 (70.81)

Vasopressor, n (%)

χ² = 35.158

 < 0.001

 No

1040 (74.93)

497 (82.83)

543 (68.91)

 Yes

348 (25.07)

103 (17.17)

245 (31.09)

Follow-up time, M (Q₁, Q₃)

137.96 (15.05, 365.00)

365.00 (365.00, 365.00)

19.27 (7.24, 51.43)

Z = 33.330

 < 0.001