TABLE 3.

Association of cardiac surgery-associated acute kidney injury and outcomes

Outcome	No CS-AKI (n = 510)	CS-AKI (n = 289)	Site-adjusted models		Multivariable models*
			Hazard ratio† (95% CI)	P value‡	Hazard ratio† (95% CI)	P value‡
Duration of mechanical ventilation, days	2 (1–4)	4 (3–7)	0.47 (0.40–0.56)	<.001	0.56 (0.46–0.67)	<.001
Length of cardiac ICU stay, days	3 (2–6)	6 (4–10)	0.49 (0.42–0.58)	<.001	0.58 (0.48–0.70)	<.001
Length of hospital stay, days	7 (5–12)	12 (8–23)	0.51 (0.43–0.62)	<.001	0.65 (0.53–0.78)	<.001

Values are median (interquartile range). CS-AKI, cardiac surgery-associated acute kidney injury; CI, confidence interval; ICU, intensive care unit.

^*Multivariable models adjust for treatment group, site, age at surgery, weight-for-age z-score, female gender, premature birth, chromosomal anomaly, non-cardiac structural abnormality, RACHS-1 category ≥3 or not assignable, cardiopulmonary bypass time ≥120 minutes, cross-clamp time ≥60 minutes, delayed sternal closure, unanticipated reoperation, cardiopulmonary resuscitation, extracorporeal membrane oxygenation, packed red blood cell transfusion on postoperative day 1 and hypoglycemia (blood glucose <60 mg/dL).

^†A hazard ratio < 1 indicates that acute kidney injury is associated with a longer duration of mechanical ventilation, cardiac ICU stay or hospital stay.

^‡P values for the comparison between groups were determined by proportional hazards regression.