Table 1 Description of baseline variables grouped by 28-day mortality for ICU patients

Demographic information

 Age, year

74.00 [69.00, 79.00]

78.00 [72.00, 83.00]

< 0.001

 Sex, n (%)

0.014

  Male

360 (48.13)

111 (58.42)

  Female

388 (51.87)

79 (41.58)

 Ethnicity, n (%)

0.264

  Caucasian

588 (78.61)

163 (85.79)

  African American

66 (8.82)

12 (6.32)

  Asian

8 (1.07)

2 (1.05)

  Hispanic

37 (4.95)

8 (4.21)

  Native American

6 (0.80)

1 (0.53)

  Other/Unknown

43 (5.75)

4 (2.11)

 First ICU location, n (%)

0.131

  MICU

98 (13.10)

25 (13.16)

  CCU-CTICU

59 (7.89)

14 (7.37)

  NICU

36 (4.81)

10 (5.56)

  Med-Surg ICU

421 (56.28)

112 (58.95)

  Cardiac ICU

57 (7.62)

11 (5.79)

  CTICU

21 (2.81)

1 (0.53)

  SICU

48 (6.42)

10 (5.26)

  CSICU

8 (1.07)

7 (3.68)

Severity of illness

 SOFA

6.03 (2.63)

7.30 (2.74)

< 0.001

 APS-III

50.00 [35.00, 68.00]

63.50 [46.25, 83.75]

< 0.001

 GCS

13.00 [10.00, 15.00]

11.00 [10.00, 15.00]

0.003

Support within the first 24 h

 Vasopressin, n (%)

< 0.001

  No

634 (84.76)

139 (73.16)

  Yes

114 (15.24)

51 (26.84)

 Ventilation, n (%)

0.002

  No

253 (33.82)

51 (21.58)

  Yes

495 (66.18)

149 (78.42)

 Dialysis, n (%)

> 0.999

  No

725 (96.93)

184 (96.84)

  Yes

23 (3.07)

6 (3.16)

Laboratory information

 Hemoglobin, g/dL

10.68 (2.22)

10.38 (2.05)

0.081

 Platelets, 10⁹/L

200.50 [149.25, 262.25]

193.50 [144.25, 273.00]

0.735

 WBCs, 10⁹/L

11.40 [7.93, 15.70]

13.21 [9.40, 19.23]

< 0.001

 INR, %

1.20 [1.10, 1.50]

1.30 [1.10, 1.80]

0.006

 PTT, s

32.50 [28.00, 40.00]

34.60 [28.90, 43.08]

0.088

 BUN, mg/dL

25.00 [17.00, 38.50]

31.00 [21.25, 55.00]

< 0.001

 Creatinine, mg/dL

1.08 [0.76, 1.64]

1.30 [0.80, 2.21]

0.002

 Sodium, mmol/L

138.73 (5.92)

139.12 (6.78)

0.472

 Potassium, mmol/L

4.16 (0.75)

4.18 (0.72)

0.692

 Calcium, mg/dL

8.25 (0.78)

8.29 (1.23)

0.722

 Chloride, mmol/L

103.59 (7.28)

103.82 (7.97)

0.728

 Glucose, mg/dL

141.00 [111.00, 180.00]

140.00 [111.25, 182.50]

0.934

 Bicarbonate, mmol/L

25.45 (6.16)

24.50 (6.36)

0.073

Charlson comorbidity

 Myocardial infarct, n (%)

0.141

  No

730 (97.59)

181 (95.26)

  Yes

18 (2.41)

9 (4.74)

Peripheral vascular disease, n (%)

0.322

  No

740 (98.93)

190 (100.00)

  Yes

8 (1.07)

0 (0.00)

 Cerebrovascular disease, n (%)

0.430

  No

712 (95.19)

184 (96.84)

  Yes

36 (4.81)

6 (3.16)

 Dementia, n (%)

0.059

  No

725 (96.93)

178 (93.68)

  Yes

23 (3.07)

12 (6.32)

 Chronic pulmonary disease, n (%)

0.870

  No

597 (79.81)

150 (78.95)

  Yes

151 (20.19)

40 (21.05)

 Rheumatic disease, n (%)

> 0.999

  No

745 (99.60)

189 (99.47)

  Yes

3 (0.40)

1 (0.53)

 Peptic ulcer disease, n (%)

0.772

  No

744 (99.47)

188 (98.95)

  Yes

4 (0.53)

2 (1.05)

 Mild liver disease, n (%)

0.075

  No

735 (98.26)

182 (95.79)

  Yes

13 (1.74)

8 (4.21)

 Severe liver disease, n (%)

> 0.999

  No

745 (99.60)

190 (100.00)

  Yes

3 (0.40)

0 (0.00)

 Diabetes, n (%)

0.766

  No

657 (87.83)

169 (88.95)

  Yes

91 (12.17)

21 (11.05)

 Paraplegia, n (%)

> 0.999

  No

747 (99.87)

190 (100.00)

  Yes

1 (0.13)

0 (0.00)

 Renal disease, n (%)

0.276

  No

669 (89.44)

164 (86.32)

  Yes

79 (10.56)

26 (13.68)

 Malignant cancer, n (%)

> 0.999

  No

689 (92.11)

175 (92.11)

  Yes

59 (7.89)

15 (7.89)

 Metastatic solid tumor, n (%)

> 0.999

  No

742 (99.20)

189 (99.47)

  Yes

6 (0.80)

1 (0.53)

 Aids, n (%)

0.867

  No

747 (99.87)

189 (99.47)

  Yes

1 (0.13)

1 (0.53)

Vital signs

 RR, /min

24.55 (8.00)

26.16 (8.19)

0.015

 HR, /min

95.71 (22.55)

97.64 (21.17)

0.268

 ROX

6.10 [3.92, 9.74]

5.65 [4.35, 8.38]

0.265