title: Development and validation of the Korean version of CKD-EPI equation to estimate glomerular filtration rate.
abstract: BACKGROUND
  The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was derived mostly from Caucasian, African-American, and Hispanic populations, whereas Asian populations were excluded. The aim of this study was to develop and validate a Korean version of the CKD-EPI equation.
  
  
  METHODS
  The study enrolled 960 individuals 18years old and older who underwent chromium-51-ethylenediaminetetraacetic-acid-based glomerular filtration rate (GFR) measurements. They were divided randomly into two groups: a development set (n=768, 80%) and a validation set (n=192, 20%). The Korean CKD-EPI equation was developed using a non-linear mixed-effect model. The performance of the equation was evaluated by calculating the bias (estimated GFR-measured GFR). The ±10% (P10) and ±30% (P30) accuracies and root mean square errors (RMSEs) of the original and Korean CKD-EPI equations were compared.
  
  
  RESULTS
  The Korean CKD-EPI equation was as follows: male, serum creatinine (Scr) ≤80μmol/L, GFR=141×(Scr/0.9)(-0.642)×(0.993)(Age); male, Scr>80μmol/L, GFR=141×(Scr/0.9)(-1.128)×(0.993)(Age); female, Scr≤62μmol/L, GFR=144×(Scr/0.7)(-0.465)×(0.993)(Age); female, Scr>62μmol/L, GFR=144×(Scr/0.7)(-1.382)×(0.993)(Age). The mean bias (mL/min/1.73m(2)) of the original CKD-EPI equation was -3.0±13.5 and that of the Korean CKD-EPI equation -2.3±13.3. The P10 and P30 of the original CKD-EPI equation were 33.9% and 82.8%; for the Korean CKD-EPI equation, the corresponding values were 35.4% and 85.9%. The RMSEs of the original and Korean CKD-EPI equations were 13.7 and 13.5, respectively.
  
  
  CONCLUSIONS
  The overall analytical performance of the Korean CKD-EPI equation was equivalent to that of the original CKD-EPI equation. The original CKD-EPI equation is therefore also valid for the Korean population.
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Tae-Dong
authors.initials: TD
authors.lastname: Jeong
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Woochang
authors.initials: W
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yeo-Min
authors.initials: YM
authors.lastname: Yun
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Sail
authors.initials: S
authors.lastname: Chun
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Junghan
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea. Electronic address: wkmin@amc.seoul.kr.
authors.forename: Won-Ki
authors.initials: WK
authors.lastname: Min
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine
keywords: Chronic Kidney Disease Epidemiology Collaboration equation; Development; Korean; Validation