Comparing the association of GFR estimated by the CKD-EPI and MDRD study equations and mortality: the third national health and nutrition examination survey (NHANES III)

BMC Nephrol. 2012 Jun 15;13:42. doi: 10.1186/1471-2369-13-42.

Abstract

Background: The Chronic Kidney Disease Epidemiology Collaboration equation for estimation of glomerular filtration rate (eGFR(CKD-EPI)) improves GFR estimation compared with the Modification of Diet in Renal Disease Study equation (eGFR(MDRD)) but its association with mortality in a nationally representative population sample in the US has not been studied.

Methods: We examined the association between eGFR and mortality among 16,010 participants of the Third National Health and Nutrition Examination Survey (NHANES III). Primary predictors were eGFR(CKD-EPI) and eGFR(MDRD). Outcomes of interest were all-cause and cardiovascular disease (CVD) mortality. Improvement in risk categorization with eGFR(CKD-EPI) was evaluated using adjusted relative hazard (HR) and Net Reclassification Improvement (NRI).

Results: Overall, 26.9% of the population was reclassified to higher eGFR categories and 2.2% to lower eGFR categories by eGFR(CKD-EPI), reducing the proportion of prevalent CKD classified as stage 3-5 from 45.6% to 28.8%. There were 3,620 deaths (1,540 from CVD) during 215,082 person-years of follow-up (median, 14.3 years). Among those with eGFR(MDRD) 30-59 ml/min/1.73 m(2), 19.4% were reclassified to eGFR(CKD-EPI) 60-89 ml/min/1.73 m(2) and these individuals had a lower risk of all-cause mortality (adjusted HR, 0.53; 95% CI, 0.34-0.84) and CVD mortality (adjusted HR, 0.51; 95% CI, 0.27-0.96) compared with those not reclassified. Among those with eGFR(MDRD) >60 ml/min/1.73 m(2), 0.5% were reclassified to lower eGFR(CKD-EPI) and these individuals had a higher risk of all-cause (adjusted HR, 1.31; 95% CI, 1.01-1.69) and CVD (adjusted HR, 1.42; 95% CI, 1.01-1.99) mortality compared with those not reclassified. Risk prediction improved with eGFR(CKD-EPI); NRI was 0.21 for all-cause mortality (p < 0.001) and 0.22 for CVD mortality (p < 0.001).

Conclusions: eGFR(CKD-EPI) categories improve mortality risk stratification of individuals in the US population. If eGFR(CKD-EPI) replaces eGFR(MDRD) in the US, it will likely improve risk stratification.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cardiovascular Diseases / mortality
  • Cross-Sectional Studies
  • Feeding Behavior* / physiology
  • Female
  • Glomerular Filtration Rate / physiology*
  • Humans
  • Kidney Failure, Chronic / epidemiology
  • Kidney Failure, Chronic / mortality*
  • Kidney Failure, Chronic / physiopathology*
  • Male
  • Middle Aged
  • Mortality / trends
  • Nutrition Surveys / methods*
  • Nutrition Surveys / trends
  • Risk Factors
  • United States / epidemiology