title: Validation of the Korean coefficient for the modification of diet in renal disease study equation.
abstract: OBJECTIVE
  Race and ethnicity are important determinants when estimatingglomerular filtration rate (GFR). The Korean coefficients for the isotope dilution mass spectrometry (IDMS) Modification of Diet in Renal Disease (MDRD) Study equations were developed in 2010. However, the coefficients have not been validated. The aim of this study was to validate the performance of the Korean coefficients for the IDMS MDRD Study equations.
  
  
  METHODS
  Equation development and validation were performed in separate groups (development group, n = 147 from 2008 to 2009; validation group, n = 125 from 2010 to 2012). We compared the performance of the original IDMS MDRD equations and modified equations with Korean coefficients. Performance was assessed by comparing correlation coefficients, bias, and accuracy between estimated GFR and measured GFR, with systemic inulin clearance using a single injection method.
  
  
  RESULTS
  The Korean coefficients for the IDMS MDRD equations developed previously showed good performance in the validation group. The new Korean coefficients for the four- and six-variable IDMS MDRD equations using both the development and validation cohorts were 1.02046 and 0.97300, respectively. No significant difference was detected for the new Korean coefficients, in terms of estimating GFR, between the original and modified IDMS MDRD Study equations.
  
  
  CONCLUSIONS
  The modified equations with Korean coefficients for the IDMS MDRD Study equations were not superior to the original equations for estimating GFR. Therefore, we recommend using the original IDMS MDRD Study equation without ethnic adjustment in the Korean population.
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Jeju, Korea.
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Oh
authors.affiliation: Department of Internal Medicine, National Medical Center, Seoul, Korea.
authors.forename: Ran-Hui
authors.initials: RH
authors.lastname: Cha
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung Sang
authors.initials: KS
authors.lastname: Yu
authors.affiliation: Department of Epidemiology and Biostatistics, Seoul National University School of Public Health, Seoul, Korea.
authors.forename: Satbyul Estella
authors.initials: SE
authors.lastname: Kim
authors.affiliation: Department of Epidemiology and Biostatistics, Seoul National University School of Public Health, Seoul, Korea.
authors.forename: Ho
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yon Su
authors.initials: YS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007201:Indicator Dilution Techniques; D007444:Inulin / Q000008:administration & dosage / Q000097:blood; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D008954:Models, Biological; D009844:Oligosaccharides / Q000008:administration & dosage / Q000097:blood; D011237:Predictive Value of Tests; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D015203:Reproducibility of Results; D056910:Republic of Korea
chemical_list: D015415:Biomarkers; D009844:Oligosaccharides; D007444:Inulin; D003404:Creatinine; C064636:sinistrin
keywords: Coefficients; Equation; Glomerular filtration rate; Inulin clearance