Table 2 Baseline characteristics in the matched cohort

Age

65.76 ± 15.73

66.08 ± 15.46

65.44 ± 15.98

t = 1.545

0.122

-0.040

Gender, n (%)

χ²=0.178

0.673

 F

2494 (42.49)

1255 (42.76)

1239 (42.21)

-0.011

 M

3376 (57.51)

1680 (57.24)

1696 (57.79)

0.011

Race, n (%)

χ²=0.763

0.683

Black

521 (8.88)

264 (8.99)

257 (8.76)

-0.008

Other

865 (14.74)

421 (14.34)

444 (15.13)

0.022

White

4484 (76.39)

2250 (76.66)

2234 (76.12)

-0.013

Weigh

84.68 ± 24.96

84.34 ± 24.28

85.02 ± 25.62

t=-1.044

0.297

0.027

Laboratory Tests

 WBC (× 10⁹/L)

13.67 ± 9.79

13.69 ± 10.82

13.64 ± 8.64

t = 0.222

0.824

-0.007

 Platelet (× 10¹²/L)

203.03 ± 111.01

203.15 ± 103.72

202.91 ± 117.86

t = 0.083

0.934

-0.002

 Hemoglobin (× 10⁹/L)

10.48 ± 1.90

10.47 ± 1.89

10.49 ± 1.91

t=-0.279

0.780

0.007

 PH

7.36 ± 0.07

7.36 ± 0.07

7.36 ± 0.08

t=-0.213

0.831

0.005

 pCO2 (mmHg)

42.25 ± 9.99

42.11 ± 9.35

42.40 ± 10.59

t=-1.111

0.267

0.027

 pO2 (mmHg)

139.60 ± 74.03

139.71 ± 71.67

139.50 ± 76.34

t = 0.105

0.916

-0.003

 Lactate level (mmol/L)

2.21 ± 1.64

2.23 ± 1.73

2.19 ± 1.54

t = 0.866

0.386

-0.024

 Ureanitrogen (mg/dL)

28.71 ± 22.20

28.92 ± 22.64

28.51 ± 21.76

t = 0.692

0.489

-0.018

 Creatinine (mg/dL)

1.49 ± 1.36

1.49 ± 1.39

1.49 ± 1.32

t=-0.056

0.955

0.002

 eGFR

73.56 ± 45.30

73.06 ± 42.60

74.05 ± 47.84

t=-0.837

0.403

0.021

Vital Signs

 MAP (mmHg)

75.55 ± 65.04

74.66 ± 11.20

76.44 ± 91.30

t=-1.049

0.294

0.020

 Respiratory rate (bpm)

19.88 ± 4.20

19.45 ± 3.88

20.31 ± 4.45

t=-7.843

< 0.001

0.192

 Spo2(%)

97.01 ± 4.35

97.42 ± 5.71

96.60 ± 2.22

t = 7.234

< 0.001

-0.368

 Temperature (°C)

36.82 ± 2.19

36.80 ± 2.78

36.84 ± 1.37

t=-0.675

0.500

0.028

Disease Severity Score

 GCS

13.27 ± 3.12

13.26 ± 3.29

13.28 ± 2.95

t=-0.292

0.770

0.008

 SAPS II score

42.10 ± 14.61

42.51 ± 14.05

41.69 ± 15.15

t = 2.159

0.031

-0.054

 SOFA score

6.44 ± 3.66

6.48 ± 3.64

6.39 ± 3.67

t = 0.978

0.328

-0.025

Comorbidities

 HF

χ²=2.389

0.122

  No

4243 (72.28)

2095 (71.38)

2148 (73.19)

0.041

  Yes

1627 (27.72)

840 (28.62)

787 (26.81)

-0.041

 MT

χ²=0.101

0.750

  No

4915 (83.73)

2462 (83.88)

2453 (83.58)

-0.008

  Yes

955 (16.27)

473 (16.12)

482 (16.42)

0.008

 CKD

χ²=0.234

0.629

  No

4856 (82.73)

2421 (82.49)

2435 (82.96)

0.013

  Yes

1014 (17.27)

514 (17.51)

500 (17.04)

-0.013

 AKF

χ²=0.227

0.634

  No

3416 (58.19)

1699 (57.89)

1717 (58.50)

0.012

  Yes

2454 (41.81)

1236 (42.11)

1218 (41.50)

-0.012

 Stroke

χ²=0.396

0.529

  No

5407 (92.11)

2710 (92.33)

2697 (91.89)

-0.016

  Yes

463 (7.89)

225 (7.67)

238 (8.11)

0.016

 COPD

χ²=0.244

0.621

  No

5323 (90.68)

2656 (90.49)

2667 (90.87)

0.013

  Yes

547 (9.32)

279 (9.51)

268 (9.13)

-0.013

 Respiratory failure, n (%)

χ²=0.573

0.449

  No

2963 (50.48)

1467 (49.98)

1496 (50.97)

0.020

  Yes

2907 (49.52)

1468 (50.02)

1439 (49.03)

-0.020

 Hypoxemia, n (%)

χ²=0.166

0.684

  No

5015 (85.43)

2502 (85.25)

2513 (85.62)

0.011

  Yes

855 (14.57)

433 (14.75)

422 (14.38)

-0.011

 Hypercapnia, n (%)

χ²=0.172

0.679

  No

5652 (96.29)

2829 (96.39)

2823 (96.18)

-0.011

  Yes

218 (3.71)

106 (3.61)

112 (3.82)

0.011

 Lactic acidosis, n (%)

χ²=0.001

0.975

  No

4527 (77.12)

2263 (77.10)

2264 (77.14)

0.001

  Yes

1343 (22.88)

672 (22.90)

671 (22.86)

-0.001