Table 2

Summary statistics and Wilcoxon–Mann–Whitney test for continuous variables*

VariableGroupNMeanSDMedianMinimumMaximump Value
AgeAKI461.0013.1960.5046.0077.000.2745
No AKI8067.6314.1971.0028.0096.00
Pre-study BUNAKI421.009.0221.0010.0032.000.4001
No AKI8017.147.3116.501.0038.00
Pre-study CrAKI41.350.311.301.091.720.0459
No AKI801.030.340.950.542.18
Pre-study BUN:CrAKI415.184.3616.479.1718.600.4816
No AKI8016.815.2716.790.8228.57
Peak BUNAKI453.7526.5846.0031.0092.000.0012
No AKI8015.707.4414.006.0044.00
Peak CrAKI43.002.221.981.726.310.0009
No AKI800.940.280.880.531.80
Peak-BUN:CrAKI419.854.4620.0514.5824.710.1755
No AKI8016.936.3715.516.9344.44
Δ CrAKI41.651.960.690.624.590.0008
No AKI80−0.090.18−0.09−0.730.47
DSA contrast (mL)AKI4173.7562.63162.50120.00250.000.6059
No AKI80159.4463.88150.0050.00325.00
CTSS contrast (mL)AKI4130.000.00130.00130.00130.000.7807
No AKI80128.757.86130.0080.00130.00
  • *Descriptive statistics for continuous variables are shown. The Wilcoxon–Mann–Whitney test was used to test the difference between the two groups. This test is a non-parametric analog to the independent two-sample t test and can be used when the dependent variables are not normally distributed.

  • p Values <0.05 (significant) are indicated in bold type.

  • AKI, acute kidney injury; BUN, blood urea nitrogen; CR, creatinine; CTSS, CT stroke study; DSA, digital subtraction angiography.