Scaling Peritoneal Dialysis

Background: Center effects in peritoneal dialysis (PD) refer to how facility patient volume impacts outcomes, with larger centers typically demonstrating better patient results. Recent U.S. policy changes have promoted PD utilization, but it remains unclear how this growth has affected center-level thresholds associated with improved outcomes. This study aimed to characterize facility-level changes in PD patient volume threshold across the United States. Methods: We conducted a retrospective observational study analyzing PD utilization across U.S. dialysis facilities from 2010-2021 using the CMS Dialysis Facility Compare database. The final analytic cohort included 8,982 unique facilities. We used mixed-effects logistic regression models with random facility effects to examine temporal trends in facilities meeting key PD volume thresholds (>0, >20, and >50 patients), adjusting for region, facility size, and profit status. Results: From 2010 to 2021, facilities with active PD services rose from 38.4% to 44.6%. The proportion of PD-offering facilities with large programs (>20 patients) increased from 22.9% to 29%, while those with very large programs (>50 patients) nearly doubled from 3.5% to 5.9%. In adjusted analyses, facilities in 2021 had significantly higher odds of maintaining programs with >20 patients (OR 6.08, 95% CI 4.82-7.68) and >50 patients (OR 8.65, 95% CI 5.34-13.99) compared to 2010. Significant regional variation persisted, with Western facilities consistently maintaining larger PD programs than other regions. Conclusions: While the United States has seen meaningful growth in facilities with large PD programs likely to achieve center effects thresholds, opportunities remain to expand PD access more broadly. Current policies have successfully encouraged some facilities to expand PD programs, but additional interventions may be needed to achieve more widespread adoption and address regional disparities.