Estimated GFR (CKD-EPI 2021)
The CKD-EPI 2021 equation is the recommended race-free formula for eGFR estimation. Used to diagnose and stage chronic kidney disease (CKD) and to guide drug dosing, contrast decisions, and specialist referral.
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eGFR (mL/min/1.73 m²)
CKD-EPI 2021 Formula:
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938Age × (1.012 if female)
Where: κ = 0.7 (female) or 0.9 (male) · α = −0.241 (female) or −0.302 (male)
Endorsed by: NKF-ASN 2021 Task Force — eliminates race as a variable for more equitable eGFR reporting.
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938Age × (1.012 if female)
Where: κ = 0.7 (female) or 0.9 (male) · α = −0.241 (female) or −0.302 (male)
Endorsed by: NKF-ASN 2021 Task Force — eliminates race as a variable for more equitable eGFR reporting.
CKD Staging Reference
KDIGO 2024 G-staging by eGFR (mL/min/1.73 m²). Full CKD staging also includes urine albumin-to-creatinine ratio (A-staging).
| Stage | eGFR Range | Description | Key Actions |
|---|---|---|---|
| G1 | ≥ 90 | Normal or high | Treat risk factors; confirm with uACR |
| G2 | 60–89 | Mildly decreased | Monitor annually; control BP, glucose |
| G3a | 45–59 | Mild–moderately decreased | Nephrology consult; SGLT2i if DM |
| G3b | 30–44 | Moderately–severely decreased | Nephrology referral; adjust medications |
| G4 | 15–29 | Severely decreased | Prepare for RRT; transplant evaluation |
| G5 | < 15 | Kidney failure | Dialysis or transplant |
Endocrine relevance: eGFR affects dosing of metformin (hold if eGFR <30), SGLT2 inhibitors (reduced efficacy <45), GLP-1 agonists, insulin clearance, and contrast media safety for imaging. Hypothyroidism and primary hyperaldosteronism can affect creatinine independently.
⚕️ Clinical note: eGFR is an estimate. Results may be less accurate in extremes of body size, muscle mass, diet (high meat intake), or acute illness. For precise assessment, 24-hour urine creatinine clearance or cystatin C-based eGFR may be preferred. CKD diagnosis requires two measurements ≥90 days apart. Based on CKD-EPI 2021 (Inker LA et al., NEJM 2021;385:1737–1749).