Survival analysis of Korean end-stage renal disease patients according to renal replacement therapy in a single center

Abstract

This study was to investigate clinical characteristics and any differential trends in survival among renal replacement therapy (hemodialysis [HD], peritoneal dialysis [PD], and kidney transplantation [KT]) in Korean end-stage renal disease (ESRD) population. We tried to analyze retrospectively the survival rate adjusted by risk factors and the relative risk stratified by key risk factors among 447 ESRD patients who began dialysis or had a kidney transplant at Ajou University Hospital from 1994 to 2004. In adjusted Cox survival curves, the KT patients had the best survival rate, and the HD patients had better survival than PD patients. The consistent trends in different subgroups stratified by age and diabetes were as following: 1) The risk of death for PD and HD was not proportional over time, 2) The relative risk of PD was similar or lower than that of HD for the first 12 months, but it became higher at later period. The significant predictors for mortality were age (over 55 yr), presence of diabetes, cerebrovascular accident at ESRD onset, and more than one time of hospitalization caused by malnutrition. Further large-scaled, multicenter-based comparative study is needed in Korean ESRD patients and more meticulous attention is required in high-risk patients.

Fig. 1

The causes of end-stage renal disease (ESRD) in each renal replacement therapy group. The distribution of causes of ESRD was similar between patients on hemodialysis and patients on peritoneal dialysis. Compared with dialysis patients, renal transplant patients were more likely (p<0.05) to have glomerulonephritis and less likely (p<0.05) to have diabetes as a cause of ESRD. CGN, chronic glomerulonephritis; DM, diabetes mellitus.

Fig. 2

The causes of death according to modality of renal replacement therapy (RRT). The proportions from each RRT represent the mortality ratios within relevant RRT group and the each segment within RRT represents the individual cause of death. While the proportion of cardiac cause in hemodialysis was higher than that of the other two groups significantly (p<0.05), the proportions of infection and cachexia in peritoneal dialysis were higher than that of the other two groups significantly (p<0.05). CVA, cerebrovascular accident. ^*: p<0.05, compared with PD and with KT; ^†: p<0.05, compared with HD and with RT; ^‡: p<0.05, compared with KT. HD, hemodialysis; PD, peritoneal dialysis; KT, kidney transplantation.

Fig. 3

Adjusted Cox survival curves according to renal replacement therapy. It was adjusted for age, diabetes, more than one time of hospitalization caused by malnutrition, cerebrovascular accident at the initiation of renal replacement therapy (RRT), which were analyzed to be independent predictors of death by time dependent Cox regression. The patient's survival rates were significantly different among groups. The KT group showed the best survival rate over the entire follow-up period and the PD group showed the lowest survival rate. KT, kidney transplantation; HD, hemodialysis; PD, peritoneal dialysis.

Fig. 4

Relative risk of death among renal replacement of therapy groups in overall patients by 12-month interval. Each relative risk is plotted against the endpoint of the follow-up interval to which it pertains. The relative risk among renal replacement therapy was not proportional over time, especially between hemodialysis (HD) and peritoneal dialysis (PD). The relative risk of HD was similar or higher than that of PD group for the first 12 months, but it became lower than that of PD at later period.

Fig. 5

Relative risk of death among renal replacement of therapy groups stratified by key risk factors (age and diabetes) by 12-month interval. Each relative risk is plotted against the endpoint of the follow-up interval to which it pertains. The relative risk among renal replacement therapy was not proportional over time, especially between hemodialysis (HD) and peritoneal dialysis (PD). Over entire 4 strata, the relative risk of HD became lower than that of PD at later period.