New Combined Serum Creatinine and Cystatin C Quadratic Formula for GFR Assessment in Children

作者:Chehade Hassib*; Cachat Francois; Jannot Anne Sophie; Meyrat Blaise Julien; Mosig Dolores; Bardy Daniel; Parvex Paloma; Girardin Eric
来源:Clinical Journal of the American Society of Nephrology, 2014, 9(1): 54-63.
DOI:10.2215/CJN.00940113

摘要

Background and objectivesThe estimated GFR (eGFR) is important in clinical practice. To find the best formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz formula across all GFR levels.Design, setting, participants, %26 measurementsTwo hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and quadratic). The performance of each model was evaluated using the Cohen correlation coefficient and the percentage reaching 30% accuracy was calculated.ResultsThe best model of correlation between iGFRs and CysC is linear; however, it presents a low coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted quadratic model with a coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P%26lt;0.001) increased the coefficient to 0.56 and the quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC quadratic formula was derived and internally validated using the cross-validation technique. This quadratic formula significantly outperformed the combined Schwartz formula, which was biased for an iGFR91 ml/min per 1.73 m(2).ConclusionsThis study allowed deriving a new combined SCreat and CysC quadratic formula that could replace the combined Schwartz formula, which is accurate only for children with moderate chronic kidney disease.

  • 出版日期2014-1-7