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 of clinical factors, including prior treatment with HD, with 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. Exposure: The primary exposure of interest was timing of PD start, categorized as PD-first, fi rst, PD- early, or PD-late. Other covariates included demographics, clinical characteristics, and routine laboratory results. Outcome: 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 fi ed at 9 months to account for lack of proportionality. Results: Among 5,224 patients who initiated PD at a DCI facility, 3,174 initiated dialysis with PD ("PD-first"), fi rst"), 942 transitioned from HD to PD within 90 days ("PD-early"), and 1,108 transitioned beyond 90 days ("PD-late"); 1,472 (28%) subsequently transferred from PD to HD. The PD-early and PD-late patients had a higher risk of transfer to HD as compared with PD-first fi rst patients (in the fi rst 9 months: adjusted hazard ratio [AHR], 1.51 [95% CI, 1.17-1.9 6] and 2.41 [95% CI, 1.94-3.00], respectively; and after 9 months: AHR, 1.16 [95% CI, 0.9 9-1.35] and AHR, 1.43 [95% CI, 1.24-1.65], respectively). More peritonitis episodes, fewer home visits, lower serum albumin levels, 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.