RT Journal Article
SR Electronic
T1 New Equations to Estimate GFR in Children with CKD
JF Journal of the American Society of Nephrology
JO J. Am. Soc. Nephrol.
FD American Society of Nephrology
SP 629
OP 637
DO 10.1681/ASN.2008030287
VO 20
IS 3
A1 Schwartz, George J.
A1 MuĂ±oz, Alvaro
A1 Schneider, Michael F.
A1 Mak, Robert H.
A1 Kaskel, Frederick
A1 Warady, Bradley A.
A1 Furth, Susan L.
YR 2009
UL http://jasn.asnjournals.org/content/20/3/629.abstract
AB The Schwartz formula was devised in the mid-1970s to estimate GFR in children. Recent data suggest that this formula currently overestimates GFR as measured by plasma disappearance of iohexol, likely a result of a change in methods used to measure creatinine. Here, we developed equations to estimate GFR using data from the baseline visits of 349 children (aged 1 to 16 yr) in the Chronic Kidney Disease in Children (CKiD) cohort. Median iohexol-GFR (iGFR) was 41.3 ml/min per 1.73 m2 (interquartile range 32.0 to 51.7), and median serum creatinine was 1.3 mg/dl. We performed linear regression analyses assessing precision, goodness of fit, and accuracy to develop improvements in the GFR estimating formula, which was based on height, serum creatinine, cystatin C, blood urea nitrogen, and gender. The best equation was \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[GFR(ml/min\ per\ 1.73\ m^{2}){=}39.1{[}height\ (m)/Scr\ (mg/dl){]}^{0.516}{\times}{[}1.8/cystatin\ C\ (mg/L){]}^{0.294}{[}30/BUN\ (mg/dl){]}^{0.169}{[}1.099{]}^{male}{[}height\ (m)/1.4{]}^{0.188}.\] \end{document} This formula yielded 87.7% of estimated GFR within 30% of the iGFR, and 45.6% within 10%. In a test set of 168 CKiD patients at 1 yr of follow-up, this formula compared favorably with previously published estimating equations for children. Furthermore, with height measured in cm, a bedside calculation of 0.413*(height/serum creatinine), provides a good approximation to the estimated GFR formula. Additional studies of children with higher GFR are needed to validate these formulas for use in screening all children for CKD.