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Estimated Glomerular Filtration Rate (eGFR) Updates

Clinical Update

Estimated Glomerular Filtration Rate (eGFR) Updates

The National Kidney Foundation and American Society of Nephrology joint task force recently released recommendations on including a race variable in eGFR reporting (PMID: 34563581).

Based on these recommendations and internal review, the following changes will occur on February 26, 2022:

Adult eGFR Creatinine Calculation

The adult eGFR creatinine equation will be updated from MDRD to the 2021 CKD-EPI creatinine equation in all blood-based creatinine panels (e.g. BMP).

This equation utilizes creatinine, sex, and age, but does not include a race variable.

The new upper reporting limit will increase from 60 to 150 mL/min/1.73m2.

Adult Cystatin C-Based eGFR

eGFR confirmation with a cystatin C-based calculation is recommended near clinical decision-making thresholds.

Two new equations will be available:

2012 eGFR cystatin C (CYSTC)

  • Variables include cystatin C, age, and sex, but not race.

2021 eGFR creatinine-cystatin C (CRECYS)

  • Variables include creatinine, cystatin C, age, and sex, but not race.

Pediatric eGFR Reporting

The task force recommendations focus on the adult population; however, several changes related to EHR transformation will affect the pediatric population:

The Bedside Schwartz creatinine factor will no longer be reported. The Bedside Schwartz creatinine equation will be provided as a comment: Bedside Schwartz equation = 0.413 x [height (cm) / serum creatinine (mg/dL)].

– The 2012 Schwartz cystatin C equation will be utilized for patients 2-17 years old when cystatin C (CYSTC) is ordered.

– The 2021 eGFR creatinine-cystatin C equation (CRECYS) is valid for adults only and will not be available to order for patients less than 18 years of age.