Table 8 Two sample T Test results for distinguishing clinical characteristics by subgroup

Gender (is male)

0.59

(0.49)

0.60

(0.49)

0.50

(0.50)

− 0.695

(P = 0.487)

4.954

(P < 1e−3)

6.664

(P < 1e−3)

Age

73.12

(14.56)

67.91

(16.27)

59.92

(18.24)

9.194

(P < 1e−3)

22.094

(P < 1e−3)

15.429

(P < 1e−3)

Weight (kg)

84.25

(35.08)

83.01

(24.32)

79.37

(25.54)

1.144

(P = 0.253)

4.659

(P < 1e−3)

4.661

(P < 1e−3)

Elixhauser index

3.53

(6.90)

5.65

(7.12)

2.37

(6.59)

− 8.334

(P < 1e−3)

4.957

(P < 1e−3)

16.136

(P < 1e−3)

Day-1 sofa score

6.51

(2.60)

8.65

(3.38)

6.50

(2.53)

− 17.575

(P < 1e−3)

0.104

(P = 0.917)

23.652

(P < 1e−3)

ICU LOS (day)

3.14

(4.67)

6.23

(7.10)

4.21

(5.52)

− 13.561

(P < 1e−3)

− 5.846

(P < 1e−3)

10.83

(P < 1e−3)

30-Day mortality

0.17

(0.38)

0.28

(0.45)

0.10

(0.30)

− 7.411

(P < 1e−3)

6.01

(P < 1e−3)

16.323

(P < 1e−3)

In-hospital mortality

0.12

(0.32)

0.26

(0.43)

0.07

(0.26)

− 8.95

(P < 1e−3)

4.729

(P < 1e−3)

16.893

(P < 1e−3)

Coagulopathy

0.10

(0.30)

0.30

(0.46)

0.12

(0.32)

− 13.388

(P < 1e−3)

− 1.823

(P = 0.068)

15.217

(P < 1e−3)

Liver disease

0.06

(0.24)

0.17

(0.38)

0.09

(0.29)

− 9.313

(P < 1e−3)

− 3.451

(P = 0.001)

7.975

(P < 1e−3)

Alcohol abuse

0.06

(0.24)

0.11

(0.31)

0.13

(0.33)

− 4.404

(P < 1e−3)

− 6.333

(P < 1e−3)

− 2.335

(P = 0.020)

Pulmonary circulation

0.10

(0.30)

0.11

(0.31)

0.06

(0.24)

− 1.117

(P = 0.264)

3.897

(P < 1e−3)

5.833

(P < 1e−3)

Neurological disease

0.15

(0.36)

0.13

(0.34)

0.22

(0.41)

1.511

(P = 0.131)

− 4.817

(P < 1e−3)

− 7.522

(P < 1e−3)

Chronic pulmonary

0.06

(0.24)

0.11

(0.31)

0.13

(0.33)

1.587

(P = 0.113)

2.033

(P = 0.042)

0.440

(P = 0.660)

Hypertension

0.70

(0.46)

0.65

(0.48)

0.49

(0.50)

2.756

(P = 0.006)

12.536

(P < 1e−3)

11.386

(P < 1e−3)

Fluid electrolyte imbalance

0.42

(0.49)

0.62

(0.49)

0.35

(0.48)

− 11.192

(P < 1e−3)

4.006

(P < 1e−3)

18.530

(P < 1e−3)

Cardiac arrhythmias

0.39

(0.49)

0.37

(0.48)

0.22

(0.42)

0.829

(P = 0.407)

10.473

(P < 1e−3)

10.991

(P < 1e−3)

Congestive heart failure

0.32

(0.47)

0.31

(0.46)

0.15

(0.36)

1.041

(P = 0.298)

12.585

(P < 1e−3)

12.926

(P < 1e−3)

Deficiency anemias

0.23

(0.42)

0.29

(0.45)

0.21

(0.41)

− 3.796

(P = 0.000)

1.072

(P = 0.284)

5.949

(P < 1e−3)

Diabetes uncomplicated

0.28

(0.45)

0.26

(0.44)

0.17

(0.37)

1.463

(P = 0.144)

8.270

(P < 1e−3)

7.646

(P < 1e−3)

Renal failure

0.28

(0.45)

0.29

(0.45)

0.07

(0.25)

− 0.490

(P = 0.625)

18.517

(P < 1e−3)

20.819

(P < 1e−3)

Hypothyroidism

0.15

(0.36)

0.13

(0.34)

0.11

(0.31)

1.662

(P = 0.097)

4.063

(P < 1e−3)

2.642

(P = 0.008)

Depression

0.12

(0.32)

0.13

(0.34)

0.14

(0.35)

− 1.093

(P = 0.275)

− 2.016

(P = 0.0439)

1.055

(P = 0.291)

Valvular disease

0.12

(0.32)

0.13

(0.34)

0.07

(0.26)

− 0.993

(P = 0.321)

4.668

(P < 1e−3)

6.549

(P < 1e−3)

Peripheral vascular

0.11

(0.32)

0.12

(0.33)

0.05

(0.23)

− 0.602

(P = 0.547)

6.533

(P < 1e−3)

8.076

(P < 1e−3)