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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Estimated Glomerular Filtration Rate (e-GFR)

Test Code(s): CRET

CPT Code(s): 82565

Test Description: Test Component:

Blood creatinine must be ordered for e-GFR to be calculated. Calculated on adult outpatients.

Included In: Creatinine, Basic Metabolic Panel, Comprehensive Metabolic Panel

Clinical Significance: Calculation is used to estimate glomerular filtration rate (GFR) from serum or plasma creatinine. E-GFR is automatically calculated on UWHC Outpatients aged 18 years and up. The test may be requested on inpatients aged 18 years and up (HealthLink code: HCEGFR).

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.

Specimen Requirements

Specimen: Blood

Collection Container: Preferred: Green cap with yellow ring (PST)
Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: Preferred: 1 mL

Sample Analyzed: Plasma or serum

Volume Required: Preferred: 0.5 mL

Specimen Processing: Centrifuge. If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial.

Specimen Transport: Transport specimen to the laboratory. Transport with coolant pack if coming from outreach location.


Reference Interval:

18 years and up: 60-120 mL/min/1.73 sqm


 e-GFR Interpretive Statement:


    Chronic kidney disease:   e-GFR < 60 mL/min/1.73 sqm


    Kidney failure:                e-GFR < 15 mL/min/1.73 sqm


 *For African Americans multiply reported e-GFR result by 1.159.

Additional Information:

Estimated Glomerular Filtration Rate calculation uses the CKD-EPI National Kidney Foundation calculation for IDMS creatinine methods. See the following website for this calculation:

GFR Estimated e-GFR egfr

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