Predictive value of the C-reactive protein-albumin-lymphocyte (CALLY) index for all-cause mortality in peritoneal dialysis patients.

BACKGROUND

The C-reactive protein-albumin-lymphocyte (CALLY) index is an emerging integrated inflammatory biomarker that reflects a patient's inflammatory, nutritional, and immune status; its application in peritoneal dialysis (PD) patients remains unexplored.

METHODS

This retrospective cohort study enrolled 955 PD patients and divided them into four groups according to the CALLY quartiles. Kaplan-Meier analysis assessed differences in survival rates. Cox regression models and time-dependent receiver operating characteristic (ROC) curves evaluated the impact of CALLY and other indices on all-cause mortality. Decision curve analysis (DCA) estimated predictive performance and clinical utility.

RESULTS

The highest CALLY quartile group exhibited a significantly lower risk of all-cause mortality compared to the lowest quartile group (HR: 0.26, 95%CI: 0.12-0.57, p = 0.001). ROC analysis demonstrated that CALLY achieved higher predictive accuracy, with an area under the curve (AUC) of 0.753 (95%CI: 0.686-0.821), compared with C-reactive protein to lymphocyte ratio (CLR) (AUC: 0.730, 95%CI: 0.656-0.803) and C-reactive protein (AUC: 0.676, 95%CI: 0.598-0.755). Adding CALLY to a conventional risk model improved discrimination (Harrell's C-index: 0.824 vs. 0.807, p = 0.014), demonstrating its potential incremental value for mortality prediction in PD patients.

CONCLUSION

The CALLY index can independently predict all-cause mortality in PD patients, and may have incremental value beyond traditional risk factors, with potential clinical decision-making value.