Table 1.

Baseline characteristics of patients with and without AKI. A summary of selected demographic and outcome variables in encounters with and without AKI (by either criterion) in our cohort.

Feature	No AKI	Any AKI	p-value
ICU stays#	59,165 (60.1%)	39,307 (39.9%)
Age (years)*	61.96 (17.12)	65.43 (16.3)	<0.001
Length of ICU stay (hours)+	25.83 (23.5)	60.55 (85.62)	<0.001
Charlson Comorbidity Index*	4.02 (2.43)	4.67 (2.47)	<0.001
Readmit#	3686 (6.2%)	3098 (7.9%)	<0.001
Gender (female)#	24,735 (41.8%)	16,372 (41.7%)	0.63
Race (black)#	806 (1.4%)	567 (1.4%)	0.292
Baseline creatinine (mg/dL)*	1.04 (0.43)	1.13 (0.52)	<0.001
Death in Hospital#	1585 (2.7%)	3588 (9.1%)	<0.001
Death in ICU#	583 (1.0%)	1961 (5.0%)	<0.001
Baseline creatinine, when available	33,741 (57.0%)	23,717 (60.3%)	<0.001

^#indicates features described by “count (%),” and tested using Fisher’s exact test;

⁺indicates features described by “median (IQR)” and tested using a Wilcoxon rank-sum test;

^*indicates features described by “mean (SD)” and tested using a two-sample t-test with unequal variances.

P-values test the difference between AKI and non-AKI encounters. Across all metrics except the proportion of black encounters and the proportion of female encounters, AKI patients are significantly different from non-AKI patients.