Estimated Glomerular Filtration Rates Show Minor but Significant Differences Between the Single and Subgroup Creatinine-Based Chronic Kidney Disease Epidemiology Collaboration Equations

The creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation can be calculated according to race, sex, and creatinine concentration (subgroup equation) or in the form expressed by one equation (single equation). Minor differences in the constants used in the CKD-EPI equations (subgroup vs single equations) could result in a significant difference in the estimated glomerular filtration rate (eGFR). We evaluated the impact of this difference in 79,709 Korean patients. The eGFR was calculated as an integer using the single and subgroup CKD-EPI equations. The differences in eGFR and GFR categories between the equations were analyzed. eGFR was higher in the subgroup equation than the single equation by 1 mL/min/1.73 m² for 12,476 (27.4%) Korean females. The GFR category based on the subgroup equation was reclassified using the single equation for 352 (0.77%) females. Based on the results, the constant of the single equation was optimized. There was no difference in eGFR values between equations using a multiplier of 1.0213 instead of 1.018 for the “white or other” females constant in the single CKD-EPI equation. Clinicians should carefully apply the CKD-EPI equation because eGFR values may differ by 1 mL/min/1.73 m² depending on the manner of calculation. To minimize these differences, the constants of the single equation should be revised.

Cockcroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equations for estimating glomerular filtration rates in cancer patients receiving cisplatin-based chemotherapy

BACKGROUND: Although the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation has been recommended for accurate estimates of glomerular filtration rate (eGFR), there is little information regarding differences in GFR estimates obtained using the Cockcroft-Gault (CG) or Modification of Diet in Renal Disease (MDRD) equations in East Asian cancer patients. We investigated discrepancies in GFR and toxicities in patients treated with cisplatin-based chemotherapy using three equations equations. METHODS: A total of 229 patients were retrospectively recruited. We calculated eGFR using the three equations and separated patients into three categories based on GFR 50 (group C) mL/min/1.73m2. We analyzed chemotherapy toxicities. RESULTS: The mean eGFR calculated using the CG was the lowest of the values derived using the three equations. Estimates using the MDRD and CKD-EPI equations resulted in reclassifying 32 (71.1%) and 33 (73.3%) of 45 patients, originally placed in group B using the CG into group C. However, only 1 (7.7%) of 13 patients placed in group B using the MDRD were reclassified into group C using the CKD-EPI. Twenty-eight of 45 patients classified into group B using the CG equation were treated with reduced doses of cisplatin. However, these patients did not show significant differences in toxicities compared with other patients taking full doses of cisplatin. CONCLUSION: The CG equations underestimated GFR compared to the MDRD and CKD-EPI equations. Therefore, when GFR is estimated using CG equations, East Asian cancer patients may receive insufficient doses of chemotherapeutic agents, including cisplatin.

Impact of the new CKD-EPI equation on the staging of patients with chronic kidney disease based on abbreviated MDRD equation / 中华肾脏病杂志

Objective To compare the estimated CFR (eCFR) values using the new chronic kidney disease epidemiology collaboration (CKD-EPI) equation with those from the abbreviated MDRD equation in a Chinese cohort with chronic kidney disease (CKD) and to analyze the impact of the new CKD-EPI equation on the staging of CKD. Methods A total of 450 Chinese patients (239 female and 211 male) with CKD were enrolled. eCFRs obtained by the CKD-EPI equation and the abbreviated MDRD equation were compared with the Bland and Altaian method. The agreement between two equations in CKD staging was assessed by Kappa test. Results Mean eGFR was 2.4 ml ·(min)-1 ·( 1.73 m2)-1 higher with the CKD-EPI equation as compared to the abbreviated MDRD equation. The percentage of CKD staging concordance between equations for stage 1, 2, 3A, 3B, 4, and 5 was 97.10% (n=67), 80.77% (n=105), 6 0.86% (n= 48), 87.69%(n=57), 90.38% (n=47) and 98.18% (n=54) respectively. Kappa index was 0.913 (95%C/: 0.881-0.945). The CKD-EPI equation reclassified 19.23% (n=25) and 39.24% (n=31) of patients with CKD stage 2 and 3A,upward to a higher eCFR category. Conclusions The new CKD-EPI equation reclassifies a number of patients to higher CKD stages, especially those classified as CKD stage 2 or 3A by the abbreviated MDRD equation.