Temporal association of peritoneal dialysis-associated peritonitis rates and outcomes with COVID-19 pandemic onset in Australia: A registry analysis

Background Effective infection control practices are recommended to prevent peritoneal dialysis-associated peritonitis (PD peritonitis). Effects of the coronavirus 2019 (COVID-19) pandemic and preventive measures on PD peritonitis outcomes are unclear. Methods Using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry data, we assessed PD peritonitis rates and outcomes in Australia before and after COVID-19 pandemic onset, defined using the World Health Organisation pandemic date (11/03/2020), between 01/01/2015 and 31/12/2022. PD peritonitis rates, trends (using interrupted time series and joinpoint regression analysis) and outcomes were analysed in prevalent patients on PD. Incident and prevalent patient characteristics commencing PD were analysed. Results In prevalent PD patients ( n = 11,499), peritonitis rates were lower post-COVID-19 (0.30 episodes per patient-year, 95% confidence interval [CI]: 0.29–0.31) than in the pre-COVID-19 period (0.35, 95% CI: 0.34–0.36, p < 0.001). PD peritonitis rates were declining prior to COVID-19 (incident rate ratio [IRR] per half-year = 0.97, 95% CI 0.96–0.98, p < 0.001), with a relative increase after COVID-19 onset (IRR = 1.05; 95% CI: 1.00–1.09, p = 0.049). There were increases in odds of PD peritonitis relapse (adjusted odds ratio (aOR): 1.41, 95% CI: 1.14–1.76) and recurrence (aOR: 1.45, 95% CI: 1.13–1.86) post-COVID-19. A total of 8999 incident patients started PD during the study period, 5763 pre-COVID-19 and 3236 post-COVID-19. Patient characteristics were similar between groups, other than rates of smoking, cerebrovascular disease and PD modality. Conclusions PD peritonitis rates have been declining in Australia, with a modest relative increase in peritonitis rates post-COVID-19 onset. Odds of PD peritonitis relapse and recurrence were higher post-COVID-19, highlighting the need for further research regarding PD practices post-pandemic.