The group's principal activity is to provide dialysis services to patients with chronic kidney failure, also known as end-stage renal disease. It provides dialysis and ancillary services to over 21,400 patients through 284 outpatient dialysis centers in 27 states. It provides acute dialysis services through contractual relationships with 130 hospitals. The group provides a variety of ancillary services like the administration of erythropoietin, also known as epogen(R), tests for bone deterioration, electrocardiograms, nerve conduction studies to test for deterioration of a patient's nerves, doppler flow testing for the effectiveness of the patient's vascular access for dialysis, and blood transfusions. It, through its renalab subsidiary provides clinical laboratory services for its dialysis operations and has designated areas for training patients in home dialysis. On 02-Apr-2004, the group acquired national nephrology associates inc and midwest kidney centers.