Comparison of outcomes on continuous ambulatory peritoneal dialysis versus automated peritoneal dialysis: results from a USA database.

Background and OBJECTIVE: Automated peritoneal dialysis (APD) is being increasingly used as an alternative to continuous ambulatory peritoneal dialysis (CAPD). However, there has been concern regarding reduced sodium removal leading to hypertension and resulting in a faster decline in residual renal function (RRF). The objective of the present study was to compare patient and technique survival and other relevant parameters between patients treated with APD and patients treated with CAPD. METHODS: Data for incident patients were retrieved from the database of the Renal Research Institute, New York. Treatment modality was defined 90 days after the start of dialysis treatment. In addition to technique and patient survival, RRF, blood pressure, and laboratory parameters were also compared. RESULTS: 179 CAPD and 441 APD patients were studied. Mean as-treated survival was 1407 days [95% confidence interval (CI) 1211 - 1601] in CAPD patients and 1616 days (95% CI 1478 - 1764) in APD patients. Adjusted hazard ratio (HR) for mortality was 1.31 in CAPD compared to APD (95% CI 0.76 - 2.25, p = NS). Unadjusted as-treated technique survival was lower in CAPD compared to APD, with HR 2.84 (95% CI 1.65 - 4.88, p = 0.002); adjusted HR was 1.81 (95% CI 0.94 - 3.57, p = 0.08). Peritonitis rate was 0.3 episodes/patient-year for CAPD and APD; exit-site/tunnel infection rate was 0.1 and 0.3 episodes/patient-year for CAPD and APD respectively (p = NS). CONCLUSIONS: Patient survival was not significantly different between APD and CAPD patients, whereas technique survival appeared to be higher in APD patients and could not be explained by differences in infectious complications. No difference in blood pressure control or decline in RRF was observed between the 2 modalities. Based on these results, APD appears to be an acceptable alternative to CAPD, although technique prescription should always follow individual judgment