Changes in patient and technique survival over time among incident peritoneal dialysis patients in Canada

Abstract

Background and objectives: In the last 15 years in Canada, there have been less stringent guidelines for peritoneal dialysis (PD) adequacy, availability of novel PD solutions, and lower PD-related peritonitis rates. Effects of these changes on outcomes of incident patients treated with PD during this period are unknown.

Design, setting, participants, & measurements: Risk of PD technique failure and mortality were compared among three incident cohorts of PD patients who initiated dialysis during the following periods: 1995-2000, 2001-2005, and 2006-2009. A multivariable model was used to evaluate time to PD technique failure using inverse probability of treatment and censoring weights accounting for changing survival and transplantation rates.

Results: Between 1995 and 2009,13,120 incident adult PD patients were identified from the Canadian Organ Replacement Register. Compared with the 1995-2000 cohort (n=5183), the risk of PD technique failure was lower among patients between 2001 and 2005 (n=4316) but similar among incident patients between 2006 and 2009 (n=3621). Cause-specific PD technique failure revealed no difference in PD peritonitis-related technique failure over time. PD technique failure due to inadequate PD was initially higher in the 2001-2005 cohort but lower in the 2006-2009 cohort compared with the 1995-2000 cohort. Relative to incident patients between 1995 and 2000, adjusted mortality was lower among incident patients between 2001 and 2005 and 2006 and 2009.

Conclusions: Survival on PD continues to improve with only modest changes in PD technique failure. Peritonitis remains an ongoing and modifiable source of PD technique failure.

Figure 1.

Distribution of incident dialysis modality in Canada from 1995 to 2009. P<0.001 by Cochrane Armitage trend test. Dark gray bar, percentage of incident peritoneal dialysis patients; light gray bar, percentage of incident hemodialysis patient by year of dialysis initiation.

Figure 2.

Two-year mortality, technique failure, and transplantation rates among incident PD patients by year of dialysis initiation. Rates are unadjusted and presented per 1000 patient-years by year of dialysis initiation along with 95% confidence intervals. Solid line, technique failure rate; long-dashed line, death rate; short-dashed line, kidney transplantation rate. PD, peritoneal dialysis.

Figure 3.

Effect of era of PD initiation on the risk of all-cause peritoneal dialysis technique failure in selected subgroups. Adjusted for age, race, sex, BMI, ESRD comorbidity index, primary diagnosis, PD modality (automated PD versus continuous ambulatory PD), province and PD center size. Bars represent the hazard ratios and 95% confidence intervals among selected subgroups. PD, peritoneal dialysis; BMI, body mass index; P-int, P value for interaction term; CI, confidence interval.