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. doi: 10.7326/0003-4819-130-6-199903160-00002.

Abstract

Background: Serum creatinine concentration is widely used as an index of renal function, but this concentration is affected by factors other than glomerular filtration rate (GFR).

Objective: To develop an equation to predict GFR from serum creatinine concentration and other factors.

Design: Cross-sectional study of GFR, creatinine clearance, serum creatinine concentration, and demographic and clinical characteristics in patients with chronic renal disease.

Patients: 1628 patients enrolled in the baseline period of the Modification of Diet in Renal Disease (MDRD) Study, of whom 1070 were randomly selected as the training sample; the remaining 558 patients constituted the validation sample.

Methods: The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equations in the validation sample.

Results: To simplify prediction of GFR, the equation included only demographic and serum variables. Independent factors associated with a lower GFR included a higher serum creatinine concentration, older age, female sex, nonblack ethnicity, higher serum urea nitrogen levels, and lower serum albumin levels (P < 0.001 for all factors). The multiple regression model explained 90.3% of the variance in the logarithm of GFR in the validation sample. Measured creatinine clearance overestimated GFR by 19%, and creatinine clearance predicted by the Cockcroft-Gault formula overestimated GFR by 16%. After adjustment for this overestimation, the percentage of variance of the logarithm of GFR predicted by measured creatinine clearance or the Cockcroft-Gault formula was 86.6% and 84.2%, respectively.

Conclusion: The equation developed from the MDRD Study provided a more accurate estimate of GFR in our study group than measured creatinine clearance or other commonly used equations.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Chronic Disease
  • Creatinine / blood*
  • Cross-Sectional Studies
  • Ethnic Groups
  • Female
  • Glomerular Filtration Rate*
  • Humans
  • Kidney Failure, Chronic / blood
  • Kidney Failure, Chronic / diet therapy
  • Kidney Failure, Chronic / physiopathology
  • Male
  • Middle Aged
  • Regression Analysis*
  • Serum Albumin / metabolism
  • Sex Factors
  • Statistics, Nonparametric
  • Urea / blood

Substances

  • Serum Albumin
  • Urea
  • Creatinine