Peritoneal Dialysis Initiation Patterns by Health Service Area during an Era of Expansion

Background: Peritoneal dialysis (PD) use in the US has historically varied significantly from region to region and community to community. Studies have reported greater PD use in higher income, Western communities compared with lower income, Northeastern communities. We sought to examine the extent to which recent increases in PD use truly resulted in expanded access at the community level (vs. increasing in areas that already had high PD use). Methods: We used the United States Renal Data System to examine PD initiation patterns across Health Service Areas (HSAs) based on pre-expansion PD use. We categorized PD use in each HSA in 2009-2010 as “high” (≥11% of patients on dialysis using PD), “medium” (5.5-<11%), or “low” (<5.5%). We then identified incident dialysis patients from 2011-2020 and used logistic regression to evaluate how the odds of PD initiation among new dialysis patients changed over this period by baseline HSA PD use category. We then re-categorized HSAs using 2020 data to determine the number that changed PD use categories over the study period. Results: We included 755 HSAs in the analysis, and subsequently examined 1,195,477 patients from those HSAs who initiated dialysis from 2011-2020. The odds of a patient initiating PD as their incident dialysis modality increased most in low PD HSAs (adjusted OR 1.49 per 5-years, 95% confidence interval CI 1.45-1.52), followed by medium (adjusted OR 1.37, 95% CI 1.35-1.39), and high PD HSAs (adjusted OR 1.17, 95% CI 1.14-1.20). More than half (51%) of HSAs previously categorized as low PD had become medium or high PD HSAs in 2020. Conclusions: Use of PD as the incident dialysis modality increased most in HSAs where it had previously been less common, suggesting that the gain in PD use was broad and not merely the result of further increases in already high use areas.