Skip to main content

Table 3 Imbalance of patient characteristics before and after propensity weighting in the assessment of in-ICU mortality

From: Association between acute kidney injury and norepinephrine use following cardiac surgery: a retrospective propensity score-weighted analysis

Variables

Before weighting

After weighting

No exposure to NE

(n = 3448)

Exposure to NE

(n = 1605)

SMD

No exposure to NE

(n = 3502)

Exposure to NE

(n = 1582)

SMD

Age, years

68 [60–76]

70 [61–77]

0.120

69 [61–76]

69 [61–76]

0.002

Male gender

2407 (67)

1080 (67)

0.054

2456 (70)

2456 (70)

0.036

BMI, kg m−2

27.48 [24.44–30.72]

26.83 [23.83–30.42]

0.017

27.50 [24.39–30.73]

27.50 [24.39–30.73]

0.005

Hypertension

1925 (56)

890 (56)

0.008

1912 (55)

1919 (55)

0.018

Coronary disease

385 (11.2)

213 (13)

0.064

380 (11)

381 (11)

0.078

Diabetes

690 (20)

294 (18)

0.043

671 (19)

671 (19)

0.003

Dyslipidemia

274 (8)

107 (7)

0.049

259 (7)

258.7 (7)

0.007

Chronic kidney disease

126 (4)

98 (6)

0.114

157 (5)

157 (5)

0.022

Peripheral vascular disease

188 (6)

76 (5)

0.033

187 (5)

187 (5)

0.018

Hemoglobin,

g dl−1

11.52 ± 1.54

11.23 ± 1.64

0.181

11.3 ± 1.56

11.4 ± 1.43

0.004

Platelet,

103 mm−3

157 ± 58

150 ± 66

0.111

146 ± 34

144 ± 35

0.007

Creatinine,

µ mol l−1

77 [64–94]

82 [67–105]

0.187

79 [65–99]

79 [65–99]

0.012

CPB time, min

84 [56–118]

100 [67–136]

0.336

88 [58–125]

88 [58–125]

0.036

Aortic clamp time, min

57 [35–83]

64 [42–94]

0.111

59 [37–87]

59 [37–87]

0.005

Surgery type

  

0.185

   

 CABG

962 (28)

468 (29)

1002 (29)

1002 (29)

0.010

 Valve surgery

1254 (36)

620 (39)

1284 (37)

1284 (37)

 Combined surgery

336 (10)

212 (13)

369 (11)

369 (11)

 Others

896 (26)

305 (19)

847 (24)

847 (24)

SAPS II

34 [28–40]

40 [33–48]

0.595

35 [30–43]

35 [30–43]

0.030

Inotropes

0 (0)

128 (8)

0.306

0 (0)

74 (5)

0.223

  1. An absolute MSD < 10% was considered to support the assumption of a balance between the groups. SMD: standardized mean differences. Data are presented as medians [interquartile ranges] or as numbers (percentages). NE: norepinephrine, CABG: coronary bypass graft, CPB: coronary bypass, SAPS II: Simplified Acute Physiology Score. Male gender and coronary disease were not selected for the propensity weighting as the P value for their association with acute kidney injury was over 20%