Table 1.

Demographic and Clinical Characteristics of the Study Population According to Chronic Kidney Disease Diagnosis, Chronic Kidney Disease in Children Study, 2005–2010

Characteristica	Total Population (n = 529)			CKD Diagnosis						P for Differenceb
				Glomerular CKD (n = 109 (21%))			Nonglomerular CKD (n = 420 (79%))
	No. of Cases	%	Median (IQR)	No. of Cases	%	Median (IQR)	No. of Cases	%	Median (IQR)
Age, years			11 (7 to 14)			14 (11 to 16)			10 (6 to 14)	<0.01
Female sex	203	38		52	48		151	36		0.03
Race										<0.01
White	354	67		58	53		296	70
African American	116	22		37	34		79	19
Other	59	11		14	13		45	11
Hispanic ethnicity	77	15		19	17		58	14		0.36
Duration of CKD, years			6.4 (3.1 to 10.3)			3.8 (1.7 to 7.4)			7.1 (3.5 to 10.8)	<0.01
Number of GFR measurements per subject										0.35
2	59	11		17	16		41	10
3	156	29		35	32		121	29
4	173	33		32	29		141	34
5	118	22		22	20		96	23
6	24	5		3	3		21	5
Years of follow-up			3.0 (2.1 to 3.9)			2.8 (1.8 to 3.7)			3.0 (2.1 to 3.9)	<0.01
GFR level, mL/minute/1.73 m2			44 (33 to 57)			48 (34 to 63)			44 (33 to 55)	0.04
Annualized percentage change in GFR, % per year			−4.7 (−13.1 to 1.7)			−10.5 (−23.4 to −1.2)			−3.9 (−11.4 to 2.2)	<0.01

Abbreviations: CKD, chronic kidney disease; GFR, glomerular filtration rate; IQR, interquartile range.

^aAt baseline, unless otherwise indicated.

^bBased on Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables.