Postoperative outcome by severity of acute kidney injury. (A) In-hospital mortality (95% CI) gradually increases the more severe the acute kidney injury; §global chi-square test; ***P < 0.001 compared with ≤ 0% increase in creatinine (chi-square tests). (B) Probability of survival gradually decreases the higher the postoperative creatinine increase (Kaplan–Meier survival curves); ***P < 0.001 compared with ≤ 0% increase in creatinine (generalized Wilcoxon tests). (C) Hospital length of stay (median and quartiles) gradually increases the higher the postoperative creatinine increase; #Kruskal–Wallis test; ***P < 0.001 compared with ≤ 0% increase in creatinine (Mann–Whitney U tests). (D) Probability of discharge gradually decreases the higher the postoperative creatinine increase (Kaplan–Meier response curves); ***P < 0.001 compared with ≤ 0% increase of creatinine increase (generalized Wilcoxon tests). Cr = creatinine; KDIGO = Kidney Disease: Improving Global Outcome; no F/U = no follow-up.