Comparison of eGFR equations for estimating kidney function in Chinese children

Glomerular filtration rate (GFR) is a critical indicator of kidney function in kidney diseases. However, well-recognized estimated GFR (eGFR) equations for pediatric populations in specific cohorts remain elusive. This study aimed to evaluate and compare the performance of various eGFR equations against measured GFR (mGFR).

A total of 221 children were included. Fourteen eGFR equations were compared with mGFR using Spearman's correlation analysis, Bland-Altman analysis, and by assessing bias, precision, and accuracy. Subgroup analyses were conducted to further evaluate the performance of eGFR equations.

The mGFR value showed no statistical difference from the eGFR values obtained using the CKiD (combined-creatinine (Cr)/cystatin C (CysC)/blood urea nitrogen (BUN)) and Tang (combined-Cr/CysC/BUN) equations (P = 0.265 and 0.653, respectively). The CKiD (combined-Cr/CysC/BUN) and Tang (combined-Cr/CysC/BUN) equations demonstrated the highest correlation (r = 0.509 and 0.455, respectively) and agreement (mean difference = -1.4 and 2.2, respectively), with the lowest bias (bias = 0.1 and 2.7, respectively) and the highest precision (median absolute value = 27.3 and 26.2, respectively) and accuracy (P₃₀ accuracies = 83.3% and 80.5%, respectively). Latent profile analysis grouped these two equations with mGFR in the same cluster. Subgroup analyses further confirmed the superior performance of these equations.

The eGFR equations incorporating Cr, BUN, and CysC simultaneously demonstrated higher accuracy and precision. The CKiD (combined-Cr/CysC/BUN) and Tang (combined-Cr/CysC/BUN) equations exhibited the highest correlation and agreement with mGFR, suggesting their potential as alternatives when mGFR is unavailable in Chinese pediatric populations.

Glomerular filtration rate (GFR) serves as a crucial indicator of kidney function. In clinical settings, accurate assessment of GFR is vital for ensuring timely therapeutic interventions and enhancing patient outcomes. The eGFR equations that simultaneously incorporate creatinine (Cr), cystatin C (CysC), and blood urea nitrogen (BUN) exhibit enhanced accuracy and precision. The CKiD (combined-Cr/CysC/BUN) and Tang (combined-Cr/CysC/BUN) equations demonstrated the strongest correlation and agreement with mGFR. This indicates that they may serve as viable alternatives when mGFR is not available in pediatric populations.