Trends in Outcomes Among Patients Initiating Peritoneal Dialysis in the United States, 2009-2018

Peritoneal dialysis (PD) use has increased since 2009. We sought to evaluate how historic disparities in outcomes across different demographic groups have changed over time.

Retrospective cohort study.

Patients initiating PD from 2009 to 2018 in the United States represented in the US Renal Data Systems (USRDS).

Patient age group, race and ethnicity, urban or rural residence, obesity status, and level of neighborhood deprivation.

Mortality and conversion to in-center hemodialysis (HD) in 1 and 2 years after dialysis initiation.

The cumulative incidence of events was estimated for each yearly cohort. Temporal trends were evaluated using Cox proportional hazards models (mortality) and Fine-Gray models (conversion to HD).

The study included 101,640 incident PD patients, of whom 38.1% were aged≥65 years, and 57.5% were White. The overall mortality 1 year after PD initiation decreased from 11.0% in 2009 to 8.4% in 2018, and the hazard decreased by 3% per 2 study years (HR, 0.97 [95% CI, 0.96-0.99]). The probability of conversion to in-center HD 1 year after PD initiation decreased from 17.8% in 2009 to 15.1% in 2018, and the hazard decreased by 2% per 2 study years (HR, 0.98 [95% CI, 0.97-1.00]). Patients over 75 years old did not experience lower conversion to HD over time (HR, 1.02 [95% CI, 0.99-1.05], P for age interaction=0.02). Overall, the hazard of conversion to HD in the 2 years after PD initiation did not improve. Hazards of mortality and conversion to HD changed similarly, regardless of urban or rural residence, race and ethnicity, obesity, or level of neighborhood deprivation.

Incomplete data on medical comorbidities.

The rate of mortality improved for incident PD patients regardless of patient demographic factors over the period 2009 to 2020. Hazards of conversion to in-center HD improved less and attenuated with longer follow-up.