Time-dependent reasons for peritoneal dialysis technique failure and mortality.

BACKGROUND: Peritoneal dialysis (PD) technique failure is high compared to hemodialysis (HD). There is a lack of data on the impact of duration of PD treatment on technique survival and on whether there is a difference in risk factors with respect to early and late failure. The aim of this study was to clarify these issues by performing a time-dependent analysis of PD technique and patient survival in a large cohort of incident PD patients.
METHODS: We analyzed 709 incident PD patients participating in the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), who started their treatment between 1997 and 2007. We compared technique and patient survival on PD in 4 periods of follow-up: within the first 3 months, and after 3 - 12 months, 12 - 24 months, and 24 - 36 months of treatment. Cox proportional hazards model was used to analyze survival on PD and technique failure. Risk factors were also identified by comparing patients that were transferred to HD with those that remained on PD. Incidence rates for every cause of dropout for each period of follow-up were calculated to establish their trends with respect to PD treatment duration.
RESULTS: There was a significant increase in transplantation rate after the first year of treatment. The rate of switching to HD was highest during the first 3 months and decreased afterward. One-, 2- and 3-year technique survival was 87%, 76%, and 66%, respectively. Age, diabetes, and cardiovascular disease appeared to be risk factors for death on PD or switch to HD: a 1-year increase in age was associated with a relative risk (RR) of PD failure of 1.04 [95% confidence interval (CI) 1.003 - 1.06]; for diabetes, RR of stopping PD after 3 months of treatment increased from 1.8 (95% CI 1.1 - 3) during the first year to 2.2 (95% CI 1.3 - 4) after the second year; cardiovascular disease had a major impact in the earliest period (RR 2.5, 95% CI 1.2 - 5) and had a stable influence further on (RR 2, 95% CI 1.1 - 3.5). Loss of 1 mL/minute residual glomerular filtration rate (rGFR) appeared to be a significant predictor of PD failure after 3 months of treatment, but within the first 2 years, RR was 1.1 (95% CI 1.04 - 1.25).
CONCLUSIONS: In The Netherlands, transplantation is a main reason to stop PD treatment. The incidence of PD technique failure is at its highest during the earliest months after treatment initiation and decreases later due to fewer catheter and abdominal complications as well as less influence of psychosocial factors. Risk factors for PD discontinuation are those responsible for patient survival: age, cardiovascular disease, diabetes, and rGFR.