Improvement in peritoneal dialysis exit-site infection rates in an integrated health care system in the United States.

Introduction: Exit-site infections (ESIs) are a significant complication of peritoneal dialysis (PD) due to their potential to progress to peritonitis, leading to higher rates of morbidity, mortality, and PD dropout. ESI rates and trends have not been generally recorded or reported by established registries. To address this gap, we studied data from ten Kaiser Permanente Southern California (KPSC) hospitals over the last decade to report yearly PD ESI rates and examine trends over time. Methods: This is a historical cohort study using data provided by the Renal Registry of Southern California Permanente Medical Group (SCPMG) for ten KPSC hospitals. Each hospital provided quarterly data from 2014-2023 with number of patients and ESI rate, reported as episodes per 100 patient-months. We modeled quarterly ESI rates across all centers (2014-2023) using a Tweedie generalized linear mixed model with calendar year and program size as fixed effects, accounting for repeated measures within center. Results: The overall mean ESI rate across the study period was 0.86 episodes per 100 patient-months (95% CI: 0.68-1.05). The observed mean ESI rate was 1.26 (95% CI: 0.98-1.60) episodes per 100 patient-months in 2014, compared with 0.72 (95% CI: 0.42-1.07) in 2023. Each additional calendar year was associated with a 6.4% relative decrease in ESI rate (rate ratio [RR] 0.94, 95% CI 0.89-0.99, Conclusion: We found a significant decline in ESI rates across ten KPSC hospitals from 2014 to 2023. This decline was not explained by growth in program size, suggesting that other factors-such as evolving infection prevention practices, staff training, or care coordination-may have contributed, though our data do not permit us to test these mechanisms directly. We encourage prospective or mechanism-specific studies to explore which factors are driving these improvements.