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Estimated Glomerular Filtration Rate (GFR) Calculator


There are several equations available for estimating GFR.1-4
This calculator uses the abbreviated MDRD equation (MDRD = Modification of Diet in Renal Disease Study), which is the one recommended by the renal Association (UK).5
See the accompanying clinical record Assessing Kidney Function
Estimated Glomerular Filtration Rate Calculator
Chronic Kidney Disease (CKD) Stage
Gender
Black ethnicity?

Age in years

Plasma creatinine umol/l

    

 

Estimated GFR (ml/min/1.73m2):

Interpretation
CKD Stage

Use the eGFR value calculated by your local laboratory in preference to the above as it is likely to be more accurate (as it may adjust for variations in creatinine measurements.

Calculator above uses the abbreviated MDRD equation:
Estimated GFR (ml/min/1.73m2) =186 x (Creat / 88.4)-1.154 x (Age)-0.203 x (0.742 if female) x (1.210 if black)

Notes

  • This equation is accurate in patients with chronic kidney disease, but it significantly underestimates GFR in healthy persons (probably due to the exclusion of healthy persons from the study used to develop this equation).4 Do not over-interpret slightly low values.
  • Stages 1 or 2 CKD should not be diagnosed on GFR alone - unless there are urinalysis, structural abnormalities or genetic factors to indicate renal disease
  • These calculations assume that the creatinine levels are relatively stable (over a few days) and not rapidly changing.
  • The MDRD equation is not valid for children - use the Counahan-Barrat method.6

The KDOQI stages of kidney disease:3

Stages of Chronic Renal Disease3
Stage Glomerular Filtration Rate
Values are normalized to an average surface area (size) of 1.73m2		 Description Management
I 90+ Normal Renal Function
(but urinalysis, structural abnormalities or genetic factors indicate renal disease)		 Observation and control of blood pressure
II 60-89 Mildly reduced renal function
(Stage 2 CKD should not be diagnosed on GFR alone - but urinalysis, structural abnormalities or genetic factors indicate renal disease)		 Observation, control of blood pressure and cardiovascular risk factors
III 30-59 Moderately reduced renal function Observation, control of blood pressure and cardiovascular risk factors
IV 15-29 Severely reduced renal function Planning for endstage renal failure
V <15 Very severe (endstage) renal failure Transplant or Dialysis

References Used

  1. Levey AS, Greene T, Kusek JW, Beck GJ. A simplified equation to predict glomerular filtration rate from serum creatinine. J Am Soc Nephrol. 2000; 11:A0828.
  2. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999 Mar 16; 130(6):461-70.
  3. National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002 Feb;39(2 Suppl 1):S1-266. No abstract available.
  4. Rule AD, Larson TS, Bergstralh EJ, Slezak JM, Jacobsen SJ, Cosio FG. Using serum creatinine to estimate glomerular filtration rate: accuracy in good health and in chronic kidney disease. Ann Intern Med. 2004 Dec 21;141(12):929-37. Summary for patients in: Ann Intern Med. 2004 Dec 21;141(12):I40.
  5. The Renal Association (UK) website
  6. Counahan-Barrat method - see Nephron.com website.

Internet and Further Reading.

Acknowledgements EMIS is grateful to Dr Huw Thomas for this calculator. ŠEMIS 2006.

Last issued 05 Jul 2006

















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PS - Health and Poverty

Perhaps the biggest cause of ill health in the world is poverty. Help to Make Poverty History. For example, why not lend some of your money to disadvantaged communities to enable them to trade their way out of poverty through schemes such as Shared Interest.

See also MAKEPOVERTYHISTORY North East for details and links to campaigns against poverty.

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