Table 1.
Clinical characteristics of the participants.
Figure 1.
Determination of the Taiwanese eGFR equations in the development set.
Taiwanese eGFR equations were derived by using linear regression of the differences on the average (i.e. the extended Bland-Altman plot). Cin and the eGFR equations were log-transformed and plotted on the log-scale. The regression line (thin solid line) and its 95% prediction interval (dotted lines) were plotted along with the identity (thick solid diagonal) line. (A) The regression equation of the Taiwanese MDRD equation was 1.309×MDRD0.912 in the (anti-logged) original unit. (B) The regression equation of the Taiwanese CKD-EPI equation was 1.262×CKD-EPI0.914 in the original unit. (C) The regression equation of the Taiwanese four-level CKD-EPI equation was 1.205×four-level CKD-EPI0.914 in the original unit.
Table 2.
Performance of the eGFR equations for the validation set.
Table 3.
Performance of the eGFR equations for the participants with Cin≥60 mL/min/1.73 m2 in the validation set.
Table 4.
Performance of the eGFR equations for the participants with Cin<60 mL/min/1.73 m2 in the validation set.
Figure 2.
Bland-Altman plot of eGFR equations versus inulin clearance (Cin) for the validation set.
The difference of log-transformed Cin and eGFR equation (ordinate) was plotted against the mean of Cin and each respective eGFR equation (abscissa). The mean difference was shown as a dotted horizontal line whereas the 95% limit of agreement was shown as the shaded area. Note that the anti-log of the difference between two log-transformed data is the ratio of the two data in the original units. Bland-Altman plot of (A) The geometric mean ratio (95% limit of agreement) was 1.023 (0.58, 1.79) for the Taiwanese MDRD in the original unit, (B) The geometric mean ratio (95% limit of agreement) was 1.025 (0.57, 1.8) for the Taiwanese CKD-EPI in the original unit, (C) The geometric mean ratio (95% limit of agreement) was 1.025 (0.57, 1.8) for the Taiwanese four-level CKD-EPI, (D) The geometric mean ratio (95% limit of agreement) was 0.93 (0.5, 1.7) for the MDRD in the original unit, (E) The geometric mean ratio (95% limit of agreement) was 0.91 (0.49, 1.7) for the CKD-EPI in the original unit and (F) The geometric mean ratio (95% limit of agreement) was 0.86 (0.46, 1.6) for the four-level CKD-EPI in the original unit.
Figure 3.
Regression of the Taiwanese eGFR equations versus inulin clearance (Cin) in the validation set.
Cin and the eGFR equations were log-transformed and plotted on the log-scale in the regression derived from the extended Bland-Altman plot. The regression line (thin solid line) and its 95% prediction interval (dotted lines) were plotted along with the identity (thick solid diagonal) line. (A) The slope (95% confidence interval) was 0.99 (0.92, 1.06) and the regression equation of the Taiwanese MDRD was 1.06×Taiwanese MDRD0.99 in the anti-logged (original) unit. (B) The slope was 1.008 (0.93, 1.08) and the regression equation of the Taiwanese CKD-EPI was 0.99×Taiwanese CKD-EPI1.01 in the original unit. (C) The slope was 1.007 (0.93, 1.08) and the regression equation of the Taiwanese four-level CKD-EPI was 0.99×Taiwanese four-level CKD-EPI1.01 in the original unit. (D) The slope was 0.9 (0.83, 0.96) and the regression equation of the MDRD equation was 1.41×MDRD0.9 in the original unit. (E) The slope was 0.92 (0.85, 0.99) and the regression equation of the CKD-EPI equation was 1.28×CKD-EPI0.92 in the original unit. (F) The slope was 0.92 (0.85, 0.99) and the regression equation of the four-level CKD-EPI was 1.22×four-level CKD-EPI0.92 in the original unit.