Fig. 3

X-tile analyses: determination of optimal cut-off values of plasma C4 for 3 endpoints. X-tile plots of 108 HD patients are shown in the first panels. The optimal cut-off values highlighted by the black circles in the first panels are detailed in the second panels, which are histograms revealing a continuous distribution based on plasma C4. Kaplan–Meier plots are displayed in third panels, with P values of the corresponding optimal cut-off value. The fourth panels demonstrate relative risk plots and the cut-off points are marked by yellow vertical bars. a The optimal cut-off value for all-cause death was 0.47 (X² = 11.386, P = 0.001). b The optimal cut-off value for CCEs was 0.39 (X² = 3.615, P = 0.057). c The optimal cut-off value for the composite endpoint was 0.44 (X² = 5.616, P = 0.018)