A comparison between 2017 FAS and 2012 CKD-EPI equations: a multi-center validation study in Chinese adult population.

Abstract

The recent guidelines recommend using the estimated glomerular filtration rate (eGFR) to evaluate renal function. There are two reported full-age-spectrum (FAS) equations in 2017, which are based on serum cystatin C concentrations with or without accompanying serum creatinine level (FASCr-Cys or FASCys). We compared the performance and assessed the applicability of the new FAS equation with the 2012 CKD-EPI (CKD-EPICys and CKD-EPICr-Cys) equation in Chinese subjects. A total of 1184 patients, mean aged 55.06year who underwent 99mTc-DTPA GFR measurements (rGFR) from four hospitals were enrolled. The bias (eGFR-rGFR), precision (interquartile range of difference [IQR]), and accuracy (the proportion of eGFR within 30% of rGFR [P30]) of eGFR and rGFR calculated by four equations were compared. Generally, the equation based on the combination of Cys and Scr performed superior to that on the basis of Cys alone, either the CKD-EPICr-Cys or the FASCr-Cys. Detailedly, referred to rGFR (67.33ml/min/1.73m2), the CKD-EPICys, CKD-EPICr-Cys, FASCys, and the FASCr-Cys estimated GFR 56.46ml/min/1.73m2, 62.79ml/min/1.73m2, 56.45ml/min/1.73m2, and 61.04ml/min/1.73m2, gave ROCAUC0.944, 0.954, 0.943, and 0.953, respectively. Another comparison as to bias, precision, P30, and RMSE with FASCr-Cys were - 2.87ml/min/1.73m2, 19.01ml/min/1.73m2, 74.16%, and 17.84ml/min/1.73m2 showed that FASCr-Cys performed approximately more accurate than other equations, as well as the diagnostic consistency of GFR staging. In the rGFR < 60ml/min/1.73m2 subgroup, the FASCr-Cys equation showed the best performance. In older subjects, compared with FASCys, CKD-EPICr-Cys, and CKD-EPICys, the FASCr-Cys equation had relatively less bias (- 8.09 vs. - 9.63, - 7.52, - 11.04, P < 0.05), most precise (15.18 vs. 16.32, 15.22, 16.63), and most accuracy, P30 was statistically different from the other equations, and achieved a ideal value > 70%. The performance of the FASCr-Cys equation is better than that of the CKD-EPICr-Cys equation in the Chinese population, particularly in the elderly. Yet, further modification of FAS equations from a large-scale study could be more suitable for the Chinese population, particularly in older people.