Multicentre registry analysis of incremental peritoneal dialysis incidence and associations with patient outcomes.

Background: Incremental peritoneal dialysis (PD) is increasingly advocated to reduce treatment burden and costs, with potential to better preserve residual kidney function. Global prevalence of incremental PD use is unknown and use in Australia and New Zealand has not been reported.
Methods: Binational registry analysis including incident adult PD patients in Australia and New Zealand (2007-2017), examining incidence of and outcomes associated with incremental PD (first recorded PD exchange volume <42 L/week (incremental) vs. ≥42 L/week (standard)).
Results: Incremental PD use significantly increased from 2.7% of all incident PD in 2007 to 11.1% in 2017 (mean increase 0.84%/year). Duration of incremental PD use was 1 year or less in 67% of cases. Male sex, Aboriginal and Torres Strait Islander (ATSI) or Māori ethnicities, age 45-59 years, medical comorbidities or treatment at a centre with low use of automated PD or icodextrin was associated with lower incidence of incremental PD use. Low body mass index and higher estimated glomerular filtration rate was associated with higher incidence. After accounting for patient and centre variables, commencing PD with an incremental prescription was associated with reduced peritonitis risk (adjusted hazard ratio 0.73, 95% confidence interval (CI) 0.61-0.86).When kidney transplantation and death were considered as competing risks, the association between incremental PD and peritonitis was not significant (sub-hazard ratio [SHR] 0.91, 95%CI 0.71-1.17, p = 0.5), however cumulative incidence of 30-day transfer to haemodialysis was lower in those receiving incremental PD (SHR 0.73, 95%CI 0.56-0.94, p = 0.01). There was no association between incremental PD and death.
Conclusions: Incremental PD use is increasing in Australia and New Zealand and is not associated with patient harm.