Table 1.

Clinical variables by AKI category

Patient CharacteristicsAll PatientsNo AKIAKI-1AKI-2AKI-3P Value
Number70024121875166
Age, yr49 (33–63)46 (32–60)48 (30–62)54 (38–65)55 (40–65)0.002
Men, %68707068620.32
Racial background, %0.1
 White/other7469788173
 Black12188712
 Asian1413141214
Diagnostic category, %<0.001
 Medical3127273143
 Surgical2520222837
 Trauma4353514120
APACHE II15 (11–20)12 (9–16)13.5 (10–17)16 (13–20)20 (16–24)<0.001
SAPS II38 (31–47)35 (27–41)36 (30–44)43 (32–51)46 (38–52)<0.001
ICNARC19 (15–24)17 (14–20)18 (14–22)20 (16–24)25 (20–30)<0.001
Length of stay, d
 Intensive care unit10 (7–16)8 (6–12)11.5 (7–16)11 (7–19)12 (8–19)<0.001
 Hospital36 (23–59)28 (17–42)39 (26–62)47 (29–66)47 (29–90)<0.001
  • Continuous variables are presented as medians and interquartile ranges; categorical variables are presented as percentages. P values represent between-column comparisons for no AKI, AKI-1, AKI-2, and AKI-3 using the Kruskal–Wallis test for continuous variables or the chi-squared test for categorical variables across categories. APACHE II, Acute Physiology, Age, Chronic Health Evaluation II; SAPS II, Simplified Acute Physiology Score II; ICNARC, Intensive Care National Audit & Research Centre Model Physiology Score.