Kidney Research and Clinical Practice (Jul 2023)

Predictive performance of the new race-free Chronic Kidney Disease Epidemiology Collaboration equations for kidney outcome in Korean patients with chronic kidney disease

  • Hyoungnae Kim,
  • Young Youl Hyun,
  • Hae-Ryong Yun,
  • Young Su Joo,
  • Yaeni Kim,
  • Ji Yong Jung,
  • Jong Cheol Jeong,
  • Jayoun Kim,
  • Jung Tak Park,
  • Tae-Hyun Yoo,
  • Shin-Wook Kang,
  • Kook-Hwan Oh,
  • Seung Hyeok Han,

DOI
https://doi.org/10.23876/j.krcp.22.158
Journal volume & issue
Vol. 42, no. 4
pp. 501 – 511

Abstract

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Background The new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations without a race coefficient have gained recognition across the United States. We aimed to test whether these new equations performed well in Korean patients with chronic kidney disease (CKD). Methods This study included 2,149 patients with CKD G1–G5 without kidney replacement therapy from the Korean Cohort Study for Outcome in Patients with CKD (KNOW-CKD). The estimated glomerular filtration rate (eGFR) was calculated using the new CKD-EPI equations with serum creatinine and cystatin C. The primary outcome was 5-year risk of kidney failure with replacement therapy (KFRT). Results When we adopted the new creatinine equation [eGFRcr (NEW)], 81 patients (23.1%) with CKD G3a based on the current creatinine equation (eGFRcr) were reclassified as CKD G2. Accordingly, the number of patients with eGFR of <60 mL/min/1.73 m2 decreased from 1,393 (64.8%) to 1,312 (61.1%). The time-dependent area under the receiver operating characteristic curve for 5-year KFRT risk was comparable between the eGFRcr (NEW) (0.941; 95% confidence interval [CI], 0.922–0.960) and eGFRcr (0.941; 95% CI, 0.922–0.961). The eGFRcr (NEW) showed slightly better discrimination and reclassification than the eGFRcr. However, the new creatinine and cystatin C equation [eGFRcr-cys (NEW)] performed similarly to the current creatinine and cystatin C equation. Furthermore, eGFRcr-cys (NEW) did not show better performance for KFRT risk than eGFRcr (NEW). Conclusion Both the current and the new CKD-EPI equations showed excellent predictive performance for 5-year KFRT risk in Korean patients with CKD. These new equations need to be further tested for other clinical outcomes in Koreans.

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