Update Type: Reference range changed
Test Updated: 02/01/2023
Test Overview
Test Methodology

Colorimetic Rate

Test Usage

Evaluation of renal function

Reference Range *

1-4 years: 0.2 - 0.6 mg/dL, 5-11 years: 0.4 - 0.9 mg/dL, 12-150 years, male: 0.7 - 1.3 mg/dL, female: 0.5 - 1.0 mg/dL
2021 CKD-EPI ≥ 60 mL/min/1.73m^2
The 2021 CKD-EPI equation should not be used to predict EGFR in unstable patients or in children. A GFR estimate between 15 and 59 for ≥ 3 months is classified as Chronic Kidney Disease (Stage 3 or 4).
GFR estimate can be interpreted accurately only during a steady state of creatinine balance. GFR estimate will overestimate true GFR if serum creatinine is rising (such as acute kidney failure) and will underestimate true GFR if serum creatinine is declining (such as resolution of acute kidney failure).
EGFR is not calculated when serum creatinine values are <0.1mg/dL.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Calculation not valid for patients less than 18 years of age and for pregnant women.
The 2021 CKD-EPI formula used to calculate the EGFR result has not been validated in patients > 100 years of age.
The EGFR should NOT be used for pharmacy drug dosing.
The calculation is not useful for estimating GFR in unstable patients or patients with acute renal failure. There are other conditions where the EGFR will be less accurate and should not be utilized. These include: extremes of body size and weight, skeletal muscle disease, paraplegia or quadriplegia, vegetarian diet, and for the calculation of dose of potentially toxic drugs that are excreted by the kidney. EGFR is NOT an orderable test.

Test Details
Days Set Up
Daily, 24 hours
Analytic Time

2 hours

Soft Order Code
MiChart Code
  • Creat
  • GFR (Glomerular Filtration Rate)
  • Glomerular Filtration Rate (GFR)
  • eGFR
  • EGFR
Chemical Pathology
STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements
Collection Instructions

Collect specimen in an SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate.

Alternate Specimen
Red top, Green top (sodium or lithium heparin) tube. [rev 11/09]
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Additional Information

The Jaffe reaction used for creatinine on the Advia 1800 can exhibit a positive bias or interference with a number of different compounds. The most common are high levels of ascorbic acid and certain cephalosporin antibiotics (Cefpirone, Cefoxitin, Cefazolin, and Cephalothin). Patients may exhibit fairly dramatic changes in serum creatinine (0.5 - 1.0 mg/dL increases) if samples happen to be drawn at peak drug levels.

CPT Code
Fee Code