EKFC Combined (Creatinine-Cystatin C)
Adult2023
Most accurate European equation combining creatinine and cystatin C
Calculate EKFC Cr-CysC
Enter the values required by this equation to estimate the result.
Enter all required values to see the result.
For educational and clinical reference use. Interpret results in clinical context.
Formula
Formula constants
| Symbol | Description | Value |
|---|---|---|
| EKFC Creatinine result (see EKFC Creatinine equation) | mL/min/1.73m² | |
| EKFC Cystatin C result (see EKFC Cystatin C equation) | mL/min/1.73m² | |
Q (creatinine) | Median serum creatinine reference (adults) | Female (≥18 y):0.70mg/dL Male (≥18 y):0.90mg/dL <18 y:Age-dependent (see Pottel et al.)mg/dL |
Q (cystatin C) | Median serum cystatin C reference | Age ≤ 50:0.83mg/L Age > 50:0.83 + 0.005 × (age − 50)mg/L |
| input | Serum creatinine | mg/dL |
| input | Serum cystatin C | mg/L |
Ageinput | Patient age | years |
Required inputs
AgeSexCreatinineCystatin C
Validated age range
2 to 120 years
Limitations
- Requires both creatinine and cystatin C measurements
- Higher cost than single-biomarker equations
- Requires standardized assays for both biomarkers
- Validated primarily in European populations
Clinical notes
- Most accurate European equation when both biomarkers available
- Simple average of EKFC-Creatinine and EKFC-Cystatin C
- Full age spectrum equation (2-120 years)
- Race-free equation
- Close to 90% of results within ±30% of measured GFR
- Recommended when both biomarkers are measured
References
- [1]Pottel H, Björk J, Rule AD, et al. Cystatin C-Based Equation to Estimate GFR without the Inclusion of Race and Sex. N Engl J Med. 2023;388(4):333-343. doi:10.1056/NEJMoa2203769
- [2]Pottel H, Björk J, Courbebaisse M, et al. Development and validation of a modified full age spectrum creatinine-based equation to estimate glomerular filtration rate. Ann Intern Med. 2021;174(2):183-191. doi:10.7326/M20-4366
- [3]Delanaye P, Cavalier E, Pottel H, Stehlé T. New and old GFR equations: a European perspective. Clin Kidney J. 2023;16(9):1375-1383. doi:10.1093/ckj/sfad039