biostudies-literature00450Levey ASNIDDK NIH HHS604-12https://www.ebi.ac.uk/biostudies/studies/S-EPMC2763564biostudies-literatureUnknown150(9)<h4>Background</h4>Equations to estimate glomerular filtration rate (GFR) are routinely used to assess kidney function. Current equations have limited precision and systematically underestimate measured GFR at higher values.<h4>Objective</h4>To develop a new estimating equation for GFR: the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.<h4>Design</h4>Cross-sectional analysis with separate pooled data sets for equation development and validation and a representative sample of the U.S. population for prevalence estimates.<h4>Setting</h4>Research studies and clinical populations ("studies") with measured GFR and NHANES (National Health and Nutrition Examination Survey), 1999 to 2006.<h4>Participants</h4>8254 participants in 10 studies (equation development data set) and 3896 participants in 16 studies (validation data set). Prevalence estimates were based on 16,032 participants in NHANES.<h4>Measurements</h4>GFR, measured as the clearance of exogenous filtration markers (iothalamate in the development data set; iothalamate and other markers in the validation data set), and linear regression to estimate the logarithm of measured GFR from standardized creatinine levels, sex, race, and age.<h4>Results</h4>In the validation data set, the CKD-EPI equation performed better than the Modification of Diet in Renal Disease Study equation, especially at higher GFR (P < 0.001 for all subsequent comparisons), with less bias (median difference between measured and estimated GFR, 2.5 vs. 5.5 mL/min per 1.73 m(2)), improved precision (interquartile range [IQR] of the differences, 16.6 vs. 18.3 mL/min per 1.73 m(2)), and greater accuracy (percentage of estimated GFR within 30% of measured GFR, 84.1% vs. 80.6%). In NHANES, the median estimated GFR was 94.5 mL/min per 1.73 m(2) (IQR, 79.7 to 108.1) vs. 85.0 (IQR, 72.9 to 98.5) mL/min per 1.73 m(2), and the prevalence of chronic kidney disease was 11.5% (95% CI, 10.6% to 12.4%) versus 13.1% (CI, 12.1% to 14.0%).<h4>Limitation</h4>The sample contained a limited number of elderly people and racial and ethnic minorities with measured GFR.<h4>Conclusion</h4>The CKD-EPI creatinine equation is more accurate than the Modification of Diet in Renal Disease Study equation and could replace it for routine clinical use.<h4>Primary funding source</h4>National Institute of Diabetes and Digestive and Kidney Diseases.Annals of internal medicineA new equation to estimate glomerular filtration rate.PMC2763564U01 DK067651-02K23 DK081017U01 DK053869U01 DK035073U01 DK053869-08U01 DK035073-14U01 DK067651UO1 DK 35073UO1 DK 053869UO1 DK 067651Levey ASKusek JWGreene TCoresh JZhang YLFeldman HIVan Lente FSchmid CHStevens LACastro AFEggers PCKD-EPI (Chronic Kidney Disease Epidemiology Collaboration)45falseA new equation to estimate glomerular filtration rate.<h4>Background</h4>Equations to estimate glomerular filtration rate (GFR) are routinely used to assess kidney function. Current equations have limited precision and systematically underestimate measured GFR at higher values.<h4>Objective</h4>To develop a new estimating equation for GFR: the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.<h4>Design</h4>Cross-sectional analysis with separate pooled data sets for equation development and validation and a representative sample of the U.S. population for prevalence estimates.<h4>Setting</h4>Research studies and clinical populations ("studies") with measured GFR and NHANES (National Health and Nutrition Examination Survey), 1999 to 2006.<h4>Participants</h4>8254 participants in 10 studies (equation development data set) and 3896 participants in 16 studies (validation data set). Prevalence estimates were based on 16,032 participants in NHANES.<h4>Measurements</h4>GFR, measured as the clearance of exogenous filtration markers (iothalamate in the development data set; iothalamate and other markers in the validation data set), and linear regression to estimate the logarithm of measured GFR from standardized creatinine levels, sex, race, and age.<h4>Results</h4>In the validation data set, the CKD-EPI equation performed better than the Modification of Diet in Renal Disease Study equation, especially at higher GFR (P < 0.001 for all subsequent comparisons), with less bias (median difference between measured and estimated GFR, 2.5 vs. 5.5 mL/min per 1.73 m(2)), improved precision (interquartile range [IQR] of the differences, 16.6 vs. 18.3 mL/min per 1.73 m(2)), and greater accuracy (percentage of estimated GFR within 30% of measured GFR, 84.1% vs. 80.6%). In NHANES, the median estimated GFR was 94.5 mL/min per 1.73 m(2) (IQR, 79.7 to 108.1) vs. 85.0 (IQR, 72.9 to 98.5) mL/min per 1.73 m(2), and the prevalence of chronic kidney disease was 11.5% (95% CI, 10.6% to 12.4%) versus 13.1% (CI, 12.1% to 14.0%).<h4>Limitation</h4>The sample contained a limited number of elderly people and racial and ethnic minorities with measured GFR.<h4>Conclusion</h4>The CKD-EPI creatinine equation is more accurate than the Modification of Diet in Renal Disease Study equation and could replace it for routine clinical use.<h4>Primary funding source</h4>National Institute of Diabetes and Digestive and Kidney Diseases.2009-01-01T00:00:00Z2009 May2024-11-13T15:47:00.024Z2019-03-27T00:25:58ZS-EPMC27635641941483910.7326/0003-4819-150-9-200905050-00006