CKD-EPI Creatinine Equation (2009)

Expressed as a single equation:

eGFR =
141 x min(SCr/κ, 1)α x
max(SCr /κ, 1)-1.209 x
0.993Age x
1.018 [if female] x
1.159 [if Black]

Abbreviations / Units

eGFR (estimated glomerular filtration rate) = mL/min/1.73 m2

SCr (standardized serum creatinine) = mg/dL

κ = 0.7 (females) or 0.9 (males)

α = -0.329 (females) or -0.411 (males)

min = indicates the minimum of SCr/κ or 1

max = indicates the maximum of SCr/κ or 1

age = years

Assays

Creatinine is assayed using methods that are traceable to IDMS assigned NIST certified reference materials. To learn more, go to nkdep.nih.gov.

Clinical Use

  • Recommended method for estimating GFR in adults.
  • Designed for use with laboratory creatinine values that are standardized to IDMS.
  • Estimates GFR from serum creatinine, age, sex, and race.
  • More accurate than the MDRD Study equation, particularly in people with higher levels of GFR.
  • Based on the same four variables as the MDRD Study equation, but uses a 2-slope “spline” to model the relationship between estimated GFR and serum creatinine, and a different relationship for age, sex and race.
  • Some clinical laboratories are still reporting GFR estimates using the MDRD Study equation. The National Kidney Foundation has recommended that clinical laboratories should begin using the CKD-EPI equation to report estimated GFR in adults.
  • Developed in 2009 by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI).

References

  1. Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604-612.
  2. Levey AS, Stevens LA. Estimating GFR using the CKD Epidemiology Collaboration (CKD-EPI) creatinine equation: more accurate GFR estimates, lower CKD prevalence estimates, and better risk predictions. Am J Kidney Dis. 2010;55(4):622-627.
  3. Matsushita K, Selvin E, Bash LD, Astor BC, Coresh J. Risk implications of the new CKD Epidemiology Collaboration (CKD-EPI) equation compared with the MDRD Study equation for estimated GFR: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Kidney Dis. 2010;55(4):648-659.
  4. White SL, Polkinghorne KR, Atkins RC, Chadban SJ. Comparison of the prevalence and mortality risk of CKD in Australia using the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Study GFR estimating equations: the AusDiab (Australian Diabetes, Obesity and Lifestyle) Study. Am J Kidney Dis. 2010;55(4):660-670.
  5. Becker BN, Vassalotti JA. A software upgrade: CKD testing in 2010. Am J Kidney Dis. 2009;55(1):8-10.
  6. Inker, AS. Frequently Asked Questions About GFR Estimates. New York: The National Kidney Foundation; 2011