Validation of glomerular filtration rate-estimating equations in Chinese children

Area of Science:

• Pediatric Nephrology
• Renal Function Assessment
• Biomarkers of Kidney Disease

Background:

• Glomerular filtration rate (GFR) is crucial for evaluating kidney function and chronic kidney disease (CKD) staging.
• Reference methods for measuring GFR in children are often complex and time-consuming.
• A lack of validated GFR-estimating tools exists for Chinese children with kidney injuries.

Purpose of the Study:

• To evaluate the accuracy of four different GFR estimation equations in Chinese children with renal injury.
• To identify reliable tools for estimating GFR in this specific pediatric population.
• To compare the performance of updated and original Schwartz, Filler, and CKiD equations against measured GFR.

Main Methods:

• Measured GFR (mGFR) was determined using double-sample plasma clearance of 99mTc-DTPA in 87 hospitalized children.
• Four GFR estimation equations (original and updated Schwartz, Filler, CKiD) were assessed.
• Statistical parameters including correlation, precision, accuracy, and Bland-Altman analysis were used for evaluation.

Main Results:

• The updated Schwartz, Filler, and CKiD equations demonstrated strong correlation, high accuracy, and good agreement with mGFR.
• These validated equations showed satisfactory performance in Bland-Altman analysis and CKD staging.
• The original Schwartz equation exhibited significant bias, poor precision, and low accuracy.

Conclusions:

• The updated Schwartz, Filler, and CKiD equations are validated for estimating GFR in Chinese children with kidney injuries.
• The updated Schwartz equation offers simplicity for bedside use, while Filler and CKiD equations provide enhanced accuracy.
• The original Schwartz equation is not recommended for GFR estimation in this pediatric cohort.