Background: With the various twin-bag systems available on the market, we decided to conduct a therapeutic equivalence study comparing ANDY-Disc (Fresenius Medical Care, Bad Homburg, Germany) with UltraBag (Baxter, Deerfield, IL) in patients on continuous ambulatory peritoneal dialysis (CAPD) therapy.
Methods: This multicenter, open-label, parallel-group, randomized trial is designed to show the therapeutic equivalence of ANDY-Disc with UltraBag. All CAPD patients from the 6 participating centers who met inclusion/exclusion criteria were enrolled into the trial. They were randomly assigned and converted from the Y-disconnect system (Ultraset; Baxter) to the twin-bag systems. The primary outcome variable is peritonitis, and secondary outcome parameters are technique failure or product defect.
Results: From April 2002 to May 2003, a total of 270 patients were recruited for this study. Overall peritonitis rates were 22.9 patient-months/episode for ANDY-Disc and 35.0 patient-months/episode for UltraBag. The overall peritonitis rate for ANDY-Disc was 53% greater compared with UltraBag, but the 95% confidence interval overlaps the prespecified margin of equivalence. There were more product defects reported with ANDY-Disc; 236 product defects compared with 17 with UltraBag. The time series of the number of product defects and peritonitis count on the ANDY-Disc arm suggests a possible cause-and-effect relationship.
Conclusion: Therapeutic equivalence of ANDY-Disc to UltraBag could not be established with respect to peritonitis. There is a trend toward greater risk for peritonitis on the Andy-Disc arm. There also is a suggestive cause-and-effect relation between the occurrence of product defect and peritonitis on the ANDY-Disc arm during the early part of the trial.