Table 5.

Overlap of classification systems

KDIGO definition	Compared criteria	AKI Stage by RIFLE, AKIN, or CK
		Stage 0, n (%)	R/Stage1, n (%)	I/Stage 2, n (%)	F/Stage 3, n (%)
Stage 0	RIFLE	1348 (99.3)	9 (0.1)	0	0
Stage 1		126 (63.0)	72 (36.0)	2 (1.0)	0
Stage 2		31 (58.5)	2 (3.8)	19 (35.9)	1 (1.9)
Stage 3		14 (36.8)	2 (5.3)	4 (10.5)	18 (47.4)
Stage 0	AKIN	1344 (99.1)	12 (0.9)	0	0
Stage 1		17 (8.5)	183 (91.5)	0	0
Stage 2		2 (3.8)	3 (5.7)	48 (90.6)	0
Stage 3		2 (5.3)	1 (2.6)	1 (2.6)	34 (89.5)
Stage 0	CK	1346 (99.3)	5 (0.4)	2 (0.2)	3 (0.2)
Stage 1		66 (33.0)	89 (44.5)	40 (20.0)	5 (2.5)
Stage 2		31 (58.5)	3 (5.7)	6 (11.3)	13 (24.5)
Stage 3		15 (39.5)	6 (15.8)	3 (7.9)	14 (36.8)

Stage 0 is considered no Acute Kidney Injury. Stage 1 is at risk. Stage 2 is injury. Stage 3 is failure. KDIGO: Kidney Disease Improving Global Outcomes; AKIN: Acute Kidney Injury Network; RIFLE: Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease; CK: Creatinine kinetics.