Fig. 1
Receiver operating characteristic curves with 95% confidence intervals for eGFRCKD-EPI (a) eGFRMDRD (b) and CCG (c). A curve lying on the diagonal line reflects the performance of a diagnostic test that is no better than chance level. The closer is the curve to the upper left-hand corner the greater is the discriminant testing capacity. Calibration plots of eGFRCKD-EPI (d) and eGFRMDRD (e) and CCG (f). The diagonal line represents the perfect calibration. If the line lies below the ideal curve, the EGFR formula overestimates the outcome, if it is above the ideal curve the formula underestimates the outcome