Systemic coagulation inflammation index and risk of mortality in peritoneal dialysis patients: a multicenter cohort study

Background The systemic coagulation inflammation (SCI) index has been investigated as a prognostic marker in several diseases. The aim of this study was to investigate the association of SCI with mortality in patients undergoing peritoneal dialysis (PD). Methods A total of 324 incident PD patients who initiated treatment between January 2011 and December 2020 were retrospectively analyzed. Patients were stratified using the previously selected outcome-specific SCI cutoffs. Mortality associations were assessed using Cox regression and, for cardiovascular disease (CVD) mortality, competing-risk methods. Results Patients were stratified with three groups based on the optimal cutoff value of SCI index. In the primary model (Model 2), lower SCI was associated with increased all-cause mortality (hazard ratio [HR], 9.32; 95% CI, 4.55–19.08, P < 0.001). For CVD mortality, the corresponding HR was 7.03 (95% CI, 3.83–12.92, P < 0.001). SCI areas under the receiver operating characteristic (ROC) curve were 0.681 and 0.688 for all-cause and CVD mortality, respectively. Significant differences in overall survival were observed in older and hypertension population. Conclusions Lower SCI index was associated with higher mortality in this PD cohort. Discrimination was modest, and the data-derived cutoffs require independent validation before clinical use.