The choice of comorbidity scoring system in Chinese peritoneal dialysis patients

Several comorbidity scoring systems have been developed and validated, mostly in western hemodialysis patients with a high risk of cardiovascular disease. The performance of comorbidity scoring, however, depends on the patient population. In this study, we determine the optimal comorbidity scoring system for predicting survival of incident Chinese PD patients. We studied 461 incident PD patients. The performance of Charlson Comorbidity Index (CCI), Hemmelgarn score, and Liu score as the survival predictor was compared. The mean age was 57.7 +/- 13.7 years. The median CCI, Hemmelgarn, and Liu scores were 4 [inter-quartile range (IQR) 2-5], 1 (IQR 0-2), and 4 (IQR 2-5), respectively. Patients were followed for 45.5 +/- 33.0 months. All 3 comorbidity scores were predictors of patient survival by univariate analysis. After adjusting for confounding factors, CCI was the best predictor of patient survival among the 3 indices, with each point increase in CCI conferring 31% excess in mortality risk [95% confidence interval (CI) 21-41%, p < 0.001]. In contrast, each point increase in Liu score confers 20% excess in mortality risk (95% CI 13-27%, p < 0.001). Although the Hemmelgarn score is an independent predictor of patient survival, over 70% of patients score 0 or 1 by this system, limiting its role as a prognostic marker. CCI should be the preferred method for quantifying comorbidity load in incident Chinese PD patients, and it is a good predictor of survival in this group of patients.