Comparative validation of the usefulness of estimated glomerular filtration rate (3-parameter and 5-parameter eGFR): Validation of 24CCr and 24CCr from correlation and discrepancy ratios with GFR conversion

Abstract

The usefulness of the 3-parameter estimated glomerular filtration rate (eGFR) and 5-parameter eGFR was examined based on the correlation and discrepancy ratio between 24-hour creatinine clearance (24CCr)and the GFR conversion formula for 24CCr (24CCrGFR conversion). The 3-parameter eGFR deviated from the comparator in a number of cases; in particular, 15.4% of patients had a discrepancy ratio of 2.01 or higher than that of 24CCrGFR conversion, suggesting overestimation of the renal function. In contrast, the 5-parameter eGFR tended to deviate below the 24CCr. However, 66.5% of deviations from the 24CCrGFR conversion converged within 0.7–1.3, and the ratio of ≥ 2.01 was 6.3%, indicating a high degree of accuracy. In the present validation, the 5-parameter eGFR was considered more useful than the 3-parameter eGFR because it showed a good correlation with the 24CCrGFR conversion, had a smaller discrepancy ratio, and was more accurate.