Mode of dialysis therapy and mortality in end-stage renal disease

Abstract

Despite considerable differences in technique and blood purification characteristics, hemodialysis and peritoneal dialysis have been thought to have similar patient outcomes. An inception cohort of 433 end-stage renal disease patients was followed prospectively for a mean of 41 mo. The outcomes of hemodialysis (HD) and peritoneal dialysis (PD) patients were compared using intention to treat analysis based on the mode of therapy at 3 mo. After adjustment for PD patients less likely to have chronic hypertension and more likely to have diabetes, ischemic heart disease, and cardiac failure at baseline (P < 0.05), a biphasic mortality pattern was observed. For the first 2 yr, there was no statistically significant difference in mortality. After 2 yr, mortality was greater among PD patients with an adjusted PD/HD hazard ratio of 1.57 (95% confidence interval [CI], 0.97 to 2.53). Both the occurrence (adjusted hazards ratio 6.87 [95% CI, 2.01 to 23.5]) and the direction (toward PD, adjusted hazards ratio 6.25 [95% CI, 1.54 to 25]) of a therapy switch were subsequently associated with mortality after 2 yr. Progressive clinical and echocardiographic cardiac disease were not responsible for this late mortality. Lower mean serum albumin levels in PD patients in the first 2 yr of therapy (3.5 +/- 0.5 versus 3.9 +/- 0.5 g/dl, P < 0.0001) accounted for a large proportion of the increase in subsequent mortality. Hemodialysis has a late survival advantage over peritoneal dialysis; antecedent hypoalbuminemia is a major marker of the increased late mortality in PD patients.