Automated peritoneal dialysis (APD) was first described in 1981, 5 years after the introduction of continuous ambulatory peritoneal dialysis (CAPD). It is increasingly used increasingly used in comparison with CAPD from 20% in 1995 to more than 33% of PD patients in North America in 1998, and in 2000, 54% of PD patients in the United States performed some form of APD.