Table 2 Baseline characteristics of study population stratified by acute kidney injury ^a

Mean age (years)

62.03 ± 14.84

62.03 ± 14.84

0.995

Males (%)

6,004 (50.3%)

1,501 (50.3%)

0.999

Admission frequency

0.57 ± 1.61

2.28 ± 2.75

<0.001

Charlson Comorbidity Index score

1.67 ± 1.72

3.66 ± 2.17

<0.001

Comorbidities (before admission)

 Myocardial infarction

122 (1%)

89 (3%)

<0.001

 Congestive heart failure

426 (3.6%)

549 (18.4%)

<0.001

 Peripheral vascular disease

161 (1.3%)

102 (3.4%)

<0.001

 Cerebrovascular disease

1,117 (9.4%)

477 (16%)

<0.001

 Dementia

204 (1.7%)

87 (2.9%)

<0.001

 COPD

1,854 (15.5%)

497 (16.7%)

0.137

 Rheumatologic disease

158 (1.3%)

55 (1.8%)

0.038

 Peptic ulcer

2,182 (18.3%)

786 (26.3%)

<0.001

 Moderate or severe liver disease

1,288 (10.8%)

285 (9.6%)

0.049

 Diabetes mellitus

5,973 (50.1%)

1,494 (50.1%)

0.984

 Hemiplegia

147 (1.2%)

68 (2.3%)

<0.001

 Chronic kidney disease

845 (7.1%)

2,248 (75.4%)

<0.001

 Solid tumor

657 (5.5%)

193 (6.5%)

0.047

 Tumor with metastasis

198 (1.7%)

40 (1.3%)

0.252

Comorbidities (during index hospitalization)

 Cardiovascular

89 (0.7%)

84 (2.8%)

<0.001

 Respiratory

100 (0.8%)

286 (9.6%)

<0.001

 Hepatic

96 (0.8%)

36 (1.2%)

0.048

 Neurologic

18 (0.2%)

48 (1.6%)

<0.001

 Hematologic

56 (0.5%)

29 (1%)

0.002

 Metabolic

5 (0%)

98 (3.3%)

<0.001

Operative categories

 Cardiothoracic

78 (0.7%)

51 (1.7%)

<0.001

 Upper GI

72 (0.6%)

12 (0.4%)

0.219

 Lower GI

128 (1.1%)

20 (0.7%)

0.049

 Hepatobiliary

197 (1.7%)

13 (0.4%)

<0.001

ICU admission during index hospitalization

898 (7.5%)

948 (31.8%)

<0.001

Mechanical ventilation

376 (3.2%)

527 (17.7%)

<0.001

Mortality

2603 (21.8%)

1,386 (46.5%)

<0.001

Severe sepsis

1,250 (10.5%)

675 (22.6%)

<0.001