In younger dialysis patients, automated peritoneal dialysis is associated with better long-term patient and technique survival than is continuous ambulatory peritoneal dialysis

Background: In the U.S. Renal Data System registry, technique and patient survival are similar with automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD). The clinical outcomes of APD and CAPD in various age groups have not been clarified. Objectives: We investigated whether patient and technique survival are different for incident dialysis patients treated with APD or CAPD in two age groups. Methods: Our retrospective study of prospectively collected data included 282 incident peritoneal dialysis (PD) patients (161 on APD, 121 on CAPD). Patients on PD for less than 3 months were excluded. The patients were divided into those less than 65 years of age and those 65 years of age or older. Overall mortality and technique failure were the primary endpoints of the study. Hazard ratios (HRs) for mortality and technique failure were calculated by the Cox proportional hazards model and were adjusted for age, sex, diabetes mellitus, initial peritoneal equilibration test (PET), weekly peritoneal and renal creatinine clearances, and PD caregiver (self or other). Results: The characteristics and clinical data were not significantly different between patients on APD and CAPD, except for age and sex. The adjusted risk for overall mortality was not different between patients on APD and CAPD (HR: 0.72; 95% CI: 0.44 to 1.20; p = 0.207). The adjusted risk for technique failure was lower in APD patients than in CAPD patients (HR: 0.58; 95% CI: 0.34 to 0.98; p = 0.041). In patients less than 65 years of age, those on APD had a significantly lower risk of mortality (HR: 0.35; 95% CI: 0.16 to 0.75; p = 0.007) and technique failure (HR: 0.52; 95% CI: 0.28 to 0.95; p = 0.034) than did those on CAPD. In patients 65 years of age and older, those on APD had risks for mortality (HR: 1.14; 95% CI: 0.53 to 2.46; p = 0.730) and technique failure (HR: 0.51; 95% CI: 0.17 to 1.50; p = 0.220) that were similar to those of patients on CAPD. Nutrition status, including serum albumin and protein catabolic rate, was not significantly different between patients on APD and on CAPD, in either younger or older patients. Conclusions: Younger Chinese patients on APD have better patient and technique survival than do those on CAPD. However, there is a strong possibility that this benefit may be confounded or accounted for by baseline differences between the APD and CAPD populations