Pediatric Glomerular Filtration Rate (P-GFR) Calculator

Estimates the Pediatric Glomerular Filtration Rate (P-GFR), as measure of kidney function by Schwartz 2009 and other two equations.

Refer to the text below the tool for more information about three of the equations used for estimating pediatric GFR.

Because measuring GFR with a filtration marker is a complex, time and cost consuming method, estimating GFR by different formulas is often preferred in clinical practice.

Several equations for pediatric GFR exist, based on personal variables such as gender, age, height or weight, as well as based on available biomarkers, such as serum creatinine or cystatin C.

The table below summarizes three of the equations used to estimate GFR in pediatric patients:

Name	GFR equation
Schwartz 2009	41.3 x height in m / serum creatinine in mg/dL
Cystatin C equation 2012	70.69 x serum cystatin C in mg/L ^-0.931
CKiD 2012	39.8 x (height in m/serum creatinine)^0.456 x (1.8/serum cystatin C)^0.418 x (30/BUN)^0.079 x a x (height in m/1.4)^0.179 a = 1 for Female & 1.076 for Male

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Estimating Pediatric Glomerular Filtration Rate

Glomerular filtration rate is the most commonly used index of kidney function. But because measuring GFR with a filtration marker is a complex, time and cost consuming method, estimating GFR by different formulas is often preferred in clinical practice.

Several equations for pediatric GFR exist, based on personal variables such as gender, age, height or weight, as well as based on available biomarkers, such as serum creatinine or cystatin C.

The table below summarizes three of the equations used to estimate GFR in pediatric patients:

Name	GFR equation
Schwartz 2009	41.3 x height in m / serum creatinine in mg/dL
Cystatin C equation 2012	70.69 x serum cystatin C in mg/L ^-0.931
CKiD 2012	39.8 x (height in m/serum creatinine)^0.456 x (1.8/serum cystatin C)^0.418 x (30/BUN)^0.079 x a x (height in m/1.4)^0.179 a = 1 for Female & 1.076 for Male

The Schwarz equation is a 2009 revision of the original bedside Schwarz GFR equation of 1976, considered to resolve any overestimation issues of the original. The equation requires serum creatinine methods calibrated to be IDMS traceable. This GFR estimation is recommended by the National Kidney Disease Education Program and is considered to be the most accurate available equation.

Estimated GFR can provide information about the stage and severity of kidney disfunction in children and help with monitoring medication efficiency.

The cystatin-C based equation utilizes the Siemens (Date Behring) method and is not yet calibrated to IFCC standards so may overestimate GFR. But its utility arises as confirmatory test where it is considered that serum creatinine eGFR is less accurate.

The CKiD equation employs serum creatinine, cystatin-C and blood urea nitrogen (BUN) and similarly to the cystatin-C based equation, may overestimate GFR because cystatin-C is not as standardized as creatinine, but still has value as secondary confirmatory test.

Estimated pediatric GFR normal range values vary with age as follows:

Age	Average GFR in mL/min/1.73m²	Normal range GFR in mL/min/1.73m²
2 - 8 days	39	17 - 60
4 - 28 days	47	26 - 68
37 - 95 days	58	30 - 86
1 - 6 months	77	39 - 114
6 - 12 months	103	49 - 157
12 - 30 months	127	67 - 292
30 months - 5 years	-	92 - 292
5 - 10 years	-	79 - 251
10 - 15 years	-	73 - 220
15 - 25 years	-	86 - 206

The pediatric GFR calculator is for use in infants, children and adolescents under 18 years old. For adults use the GFR calculator.

References

Original reference

Schwartz GJ and Work DF. Measurement and estimation of GFR in children and adolescents. J Am Soc Nephrol. 2009; 4(11): 1832-643.

Schwartz GJ, Munoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009; 20: 629-637.

Schwartz GJ, Schneider MF, Maier PS, et al. Improved equations estimating GFR in children with chronic kidney disease using an immunonephelometric determination of cystatin C. Kidney Int. 2012; 82(4):445-453.

Grubb A, Blirup-Jensen S, Lindstrom V, Schmidt C, Althaus H, Zegers I. First certified reference material for cystatin C in human serum ERM-DA471/IFCC. Clin Chem Lab Med. 2010; 48(11):1619-1621.

Validation

Staples A, LeBlond R, Watkins S, Wong C, Brandt J. Validation of the revised Schwartz estimating equation in a predominantly non-CKD population. Pediatr Nephrol. 2010 ;25(11):2321-6.

Other references

Heilbron DC, Holliday MA, al-Dahwi A, Kogan BA. Expressing glomerular filtration rate in children [published correction appears in Nephrol. 1991; 5(1):5-11].

Du L. et al. Pediatric reference ranges for glomerular filtration rate determined by a single injection of Tc-99m DTPA. J Nucl Med May 2009 vol. 50 no. supplement 2 1375.

Muhari-Stark E, Burckart GJ. Glomerular Filtration Rate Estimation Formulas for Pediatric and Neonatal Use. J Pediatr Pharmacol Ther. 2018; 23(6):424-431.

Specialty: Pediatrics

Abbreviation: P-GFR

Article By: Denise Nedea

Published On: September 6, 2020 · 12:00 AM

Last Checked: September 6, 2020

Next Review: September 6, 2025