Skip to main content
. Author manuscript; available in PMC: 2019 Jul 1.
Published in final edited form as: Kidney Int. 2018 May 5;94(1):170–177. doi: 10.1016/j.kint.2018.01.034

Table 2.

Measures of agreement for CKiD and CKD-EPI estimating GFR equations with iohexol GFR as the reference for 279 person-visits contributed by 187 young adults with a history of pediatric CKD.

iGFR CKiDSCr-Cys CKiDSCr CKD-EPISCr CKD-EPICys CKD-EPISCr-Cys
Mean, ml/min|1.73m2 49.2 50.7 43.6 57.4 51.8 52.4
Standard deviation 22.5 21.1 20.2 30.8 29.4 29.2
Average bias, ml/min|1.73m2
(95%CI)		 0 +1.5
(+0.6, +2.5) 		−5.6
(−7.1, −4.2) 		+8.2
(+6.7, +9.7) 		+2.7
(+1.3, +4.0) 		+3.3
(+2.1, +4.4)
Ratio of SDs
(95%CI)		 1 0.94
(0.89, 0.99) 		0.89
(0.81, 0.97) 		1.39
(1.28, 1.50) 		1.32
(1.24, 1.40) 		1.31
(1.24, 1.38)
Correlation 1 0.94 0.89 0.91 0.90 0.94
RMSE, ml/min|1.73m2 0 7.1 9.2 13.0 12.3 10.0
% within 30% of iGFR Reference 90% 71% 66% 74% 76%

Abbreviations: Iohexol GFR (iGFR); CKiD eGFR equation based on serum creatinine and cystatin C (CKiDSCr-Cys); CKiD eGFR equation based on serum creatinine only (CKiDSCr); CKD-EPI eGFR equation based on serum creatinine only (CKD-EPISCr), cystatin C only (CKD-EPICys), and serum creatinine and cystatin C (CKD-EPISCr-Cys); standard deviations (SDs); root mean square error (RMSE).