Table 4.

Nephrotoxicity.

	All (N = 4177)	Gentamicin Group (n = 1590)	Control Group (n = 2587)	p-value
Overall nephrotoxicity rate	85 (2.0)	39 (2.5)	46 (1.8)	0.166
Nephrotoxicity rate by type of surgery
Hip and knee arthroplasty	76/2675 (2.8)	32/990 (3.2)	44/1685 (2.6)	0.661
Spine fusion	9/1502 (0.6)	7/600 (1.2)	2/902 (0.2)	0.034
Severity of nephrotoxicity by RIFLE criteria
Risk	59/85 (69.4)	26/39 (66.7)	33/46 (71.7)	0.485
Injury	22/85 (25.9)	12/39 (30.8)	10/46 (21.7)
Failure	4/85 (4.7)	1/39 (2.6)	3/46 (6.5)
Median time to nephrotoxicity, days (IQR)	3 (2–3)	2 (1–3)	3 (2–3)	0.0005
Peak SCr, g/dL (IQR)	0.8 (0.7–0.9)	0.8 (0.6–0.9)	0.8 (0.7–1.0)	0.002

RIFLE: Risk, Injury, Failure, Loss, End-stage kidney disease; IQR: interquartile range; SCr: serum creatinine.

All values shown as n (%) unless otherwise specified.