Peritoneal dialysis patient survival: a comparison between a Swedish and a Korean centre.
BACKGROUND
Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival. In addition, the literature suggests that dialysis patient survival may be better in Asian than in Caucasian patients.


METHODS
The influence of centre and patient characteristics on patient survival was investigated in 132 Korean and 106 Swedish incident PD patients, who underwent initial biochemical measurements and assessment of adequacy of dialysis, nutritional status, RRF and peritoneal transport characteristics.


RESULTS
At the start of PD, Korean patients had a higher prevalence of diabetes, peritoneal Kt/V(urea), peritoneal creatinine clearance and peritoneal fluid removal, and lower body mass index, RRF and dialysate to plasma creatinine concentration ratio (D/P Cr) compared with Swedish patients. Significantly more patients from Korea were placed on temporary haemodialysis before PD (100 out of 132) when compared with Swedish patients (21 out of 106). During the follow-up, there was a significantly higher rate of transfer to other units in Korea and a significantly higher rate of kidney transplantation in Sweden. On Kaplan-Meier analysis, overall patient survival did not differ and relative risk for death was also not different between the two centres even after adjustment for age, diabetes, cardiovascular disease, RRF and D/P Cr. On Cox proportional hazards multivariate analysis, age, diabetes, RRF and D/P Cr were found to be independent predictors of mortality in the combined cohort of patients. While age, diabetes and D/P Cr were independent predictors of mortality in Korean patients, age and RRF independently predicted mortality in Swedish patients.


CONCLUSIONS
Although there were significant differences in centre and patient characteristics, we were unable to confirm a survival advantage for Korean over Swedish PD patients. The results of this study suggest that the reported difference in survival between Asian and Caucasian dialysis patients may have been due, in part, to differences in centre and patient characteristics rather than to race as such. The genetic influence on patient characteristics remains, however, to be elucidated.
Chung
Sung Hee
SH
Hyonam Kidney Laboratory, Soon Chun Hyang University, 657 Hannam-dong, Yongsan-ku, Seoul 140-743, Korea.
Heimbürger
Olof
O
Lindholm
Bengt
B
Lee
Hi Bahl
HB
D000367:Age Factors; D000368:Aged; D003404:Creatinine / Q000378:metabolism; D006801:Humans; D007723:Korea; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000401:mortality*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis; D013548:Sweden; D014508:Urea / Q000378:metabolism
D014508:Urea; D003404:Creatinine