Recovery of renal function in continuous ambulatory peritoneal dialysis: a study of National CAPD Registry data

From January 1981 to July 1988, the U.S. National CAPD Registry followed 23,771 patients on CAPD or CCPD for 3 months or more in 498 participating centers. Of these patients, 281 were deemed to have enough recovery of renal function to do without dialysis for at least 3 months. The median time on PD before recovery was 126 days in 138 patients treated only by PD from the start of dialysis. The median time to recovery in 106 patients was 238 days from the start of any chronic dialysis. A Cox model analysis revealed significantly (p less than 0.05) increased chances for renal function recovery in patients with systemic immunological diseases with renal involvement (relative risk for recovery [rr] = 2.48), patients with renal infarction related to renal vascular occlusion (rr = 4.13), and patients greater than 60 years of age compared to a younger group (rr = 1.72). However, patients greater than 60 and less than 21 experienced similar recovery rates. Reduced chances (p less than 0.05) for recovery were associated with diabetic glomerulosclerosis (rr = 0.25) and polycystic kidney disease (rr = 0.13). These findings show that renal function recovery rates in chronic hemodialysis and chronic peritoneal dialysis cannot be properly compared unless all risk factors (favoring or against recovery) are balanced, as in a prospective randomized trial.