Comparison of estimated glomerular filtration rates in Chinese patients with chronic kidney disease among serum creatinine-, cystatin-C- and creatinine-cystatin-C-based equations: A retrospective cross-sectional study

Accurate estimation of glomerular filtration rate (GFR) and staging of chronic kidney disease (CKD) are important. Thus far, few studies in China have systematically assessed the differences among the various estimated GFR (eGFR) equations in large cohort. A total of 6287 CKD patients and 679 healthy individuals were enrolled. To estimate the GFR values in patients, MDRD, MDRD-China (MDRD-C), CKD-EPI, cystatin-C-China (CysC-C), cystatin-C-KDIGO (CysC-K), and creatinine-cystatin C-KDIGO (Cr-CysC) equations were used. The κ values between the MDRD, MDRD-C, Cr-CysC, CysC-K, and CysC-C equations and the CKD-EPI equation were 0.864, 0.914, 0.638, 0.487, and 0.388, respectively. For patients with lower-stage CKD, the GFR values from MDRD and MDRD-C equations were the highest compared with other equations, whereas the GFR values from CysC-C and CysC-K equations were the lowest. For patients with higher-stage CKD, the CKD-EPI, MDRD, MDRD-C, and Cr-CysC equations showed good consistencies among each other, whereas eGFR from CysC-C equation were higher and the CysC-C and CysC-K equations showed many obviously overestimated outliers. CKD-EPI and Cr-CysC equations were better correlated and consistent with each other in most of the CKD stages. The CKD-EPI and Cr-CysC equations may be more suitable for the comprehensive estimation of GFR in patients with CKD.