Table 4.

Area under receiver operating curve of RDW and severity scales at different AKI stages.

	All subjects (N = 18279)		AKI stage 1 (N = 5557)		AKI stage 2 (N = 6798)		AKI stage 3 (N = 5924)
	AUC (95% CI)	P	AUC (95% CI)	P	AUC (95% CI)	P	AUC (95% CI)	P
RDW	0.718 (0.712–0.725)		0.713 (0.701–0.725)		0.684 (0.673–0.695)		0.757 (0.746–0.768)
APS III	0.706 (0.700–0.713)	<0.01	0.682 (0.670–0.695)	<0.01	0.675 (0.664–0.686)	0.297	0.755 (0.744–0.766)	0.781
RDW + APS III	0.758 (0.752–0.764)	<0.01	0.741 (0.729–0.752)	<0.01	0.725 (0.714–0.735)	<0.01	0.802 (0.792–0.812)	<0.01
MLODS	0.659 (0.652–0.666)	<0.01	0.660 (0.647–0.672)	<0.01	0.608 (0.596–0.619)	<0.01	0.709 (0.698–0.721)	<0.01
RDW + MLODS	0.741 (0.735–0.748)	<0.01	0.734 (0.722–0.745)	<0.01	0.700 (0.689–0.711)	<0.01	0.787 (0.776–0.797)	<0.01
SOFA	0.638 (0.631–0.645)	<0.01	0.633 (0.620–0.646)	<0.01	0.586 (0.574–0.597)	<0.01	0.695 (0.683–0.707)	<0.01
RDW + SOFA	0.732 (0.726–0.739)	<0.01	0.724 (0.712–0.736)	<0.01	0.689 (0.678–0.700)	0.115	0.780 (0.769–0.791)	<0.01
OASIS	0.642 (0.635–0.649)	<0.01	0.590 (0.577–0.603)	<0.01	0.643 (0.631–0.654)	<0.01	0.691 (0.679–0.702)	<0.01
RDW + OASIS	0.750 (0.743–0.756)	<0.01	0.726 (0.714–0.738)	<0.01	0.727 (0.717–0.738)	<0.01	0.792 (0.781–0.802)	<0.01
SIRS	0.522 (0.514–0.529)	<0.01	0.506 (0.493–0.519)	<0.01	0.510 (0.498–0.522)	<0.01	0.554 (0.542–0.567)	<0.01
RDW + SIRS	0.720 (0.713–0.726)	0.080	0.713 (0.701–0.725)	0.964	0.685 (0.674–0.696)	0.402	0.760 (0.749–0.771)	0.018

Note: AKI, acute kidney injury; AUC, area under curve; CI, confidence interval; SE, standard error; RDW, red blood cell distribution width; APS III, acute physiology and chronic health evaluation III; MLODS, modified logistic organ dysfunction system; SOFA, sequential organ failure assessment; OASIS, Oxford acute severity of illness score; SIRS, systemic inflammatory response syndrome.