Table 4.

Comparison of GFR prediction equations using published coefficients and coefficients derived from training data set of 349 children of the CKiD study^a

Model	Data Source	N	Ageb	Agent	GFRb	Equation for eGFR
Scr-based formulas
Counahan et al.2	Original	108	0.2 to 14 (n = 103)	51Cr-EDTA	4 to 200	43.00[height/Scr]
	CKiD	349	1.2 to 17.1	Iohexol	16 to 93	41.30[height/Scr]
Leger et al.35	Original	97	0.8 to 21	51Cr-EDTA	97 (31 to 200)	0.641[weight/Scr] + 16.063[height2/Scr]
	CKiD	349	1.2 to 17.1	Iohexol	44 (16 to 93)	0.542[weight/Scr] + 9.948[height2/Scr]
Cystatin C–based formulas
Filler et al.36	Original	536	11.2 ± 4.5	99mTc-DTPA	103 ± 41	91.62[1/CysC]1.123
	CKiD	349	10.6 ± 4.2	Iohexol	44 ± 15	66.22[1/CysC]0.777
Grubb et al.27	Original	536	<18 (n = 85)	Iohexol	113, 99, 63c	84.69[1/CysC]1.680[1.3841(age < 14)]
	CKiD	349	<18	Iohexol	41, 42, NAc	68.06[1/CysC]0.781[0.9661(age < 14)]
Scr- and cystatin C–based formulas
Bouvet et al.20	Original	100	1.4 to 22.8	51Cr-EDTA	95 (18 to 200)	63.2[1.2/CysC]0.56[(96/88.4)/(Scr)]0.35[weight/45]0.30[age/14]0.40
	CKiD	349	1.2 to 17.1	Iohexol	44 (16 to 93)	46.1[1.2/CysC]0.33[(96/88.4)/(Scr)]0.55[weight/45]0.77[age/14]0.17
Zappitelli et al.21	Original	103	12.7 ± 4.7	Iothalamate	74 ± 36	43.82[1/CysC]0.635[1/Scr]0.547[1.35height]
	CKiD	349	10.6 ± 4.2	Iohexol	44 ± 15	25.38[1/CysC]0.331[1/Scr]0.602[1.88height]

^aGFR, ml/min per 1.73 m²; eGFR, ml/min per 1.73 m², except Leger's and Bouvet's in ml/min; height, m; Scr, mg/dl; CysC, cystatin C, mg/L; weight, kg.

^bDescriptive statistics (e.g., range, mean ± SD) for CKiD sample are those reported in the original publications.

^cMedians for age <14, 14 to <18, ≥18 yr.