Peritoneal Dialysis Technique Survival: A Cohort Study

Rationale & Objective Reasons for transfer from peritoneal dialysis (PD) to hemodialysis (HD) remain incompletely understood. Among incident and prevalent patients receiving PD, we evaluated the association between prior treatment with HD and PD technique survival. Study Design Retrospective cohort study. Setting & Participants Adults who initiated PD at a Dialysis Clinic, Inc. (DCI) outpatient facility between January 1, 2010 and September 30, 2019. Exposures The primary exposure of interest was timing of PD start, categorized as PD-first, PD-early, or PD-late. Other covariates included demographics, clinical characteristics, and routine laboratory results. Outcomes Modality switch from PD to HD sustained for more than 90 days. Analytical Approach Multivariable Fine-Gray models with competing risks and time-varying covariates, stratified at 9 months to account for lack of proportionality. Results Among 5224 patients who initiated PD at a DCI facility, 3174 initiated dialysis with PD ("PD-first"), 942 transitioned from HD to PD within 90 days ("PD-early"), and 1108 transitioned beyond 90 days ("PD-late"); 1472 (28%) subsequently transferred from PD to HD. PD-early and PD-late patients had higher risk of transfer to HD as compared to PD-first patients [adjusted hazard ratio (aHR) 1.51 (95% CI: 1.17-1.96) and 2.41 (1.94-3.00), respectively, in the first 9 months and aHR 1.16 (0.99-1.35) and 1.43 (1.24-1.65), respectively, after 9 months]. More peritonitis episodes, fewer home visits, lower serum albumin, lower residual kidney function, and lower peritoneal clearance calculated with weekly Kt/V were additional risk factors for PD-to-HD transfer. Limitations Missing data on dialysis adequacy and residual kidney function, confounded by short PD technique survival. Conclusions Initiating dialysis with PD is associated with greater PD technique survival, though many of those who initiate PD late in their dialysis course still experience substantial time on PD. Peritonitis, lower serum albumin, and lower Kt/V are risk factors for PD-to-HD transfer that may be amenable to intervention.