A COMPARISON OF CAUSE OF DEATH BETWEEN PATIENTS TREATED WITH HEMODIALYSIS AND PERITONEAL-DIALYSIS

Mortality rates associated with peritoneal dialysis (PD) have been fou nd to be higher than those associated with hemodialysis (HD) among pre valent U.S. patients over the age of 55 in the preceding study. Given the substantial technical differences between PD and HD, causes of dea th might also be expected to differ between these dialytic modalities. In order to help elucidate the relative contributions of these techni cal differences and to further the understanding of the excess mortali ty observed among PD-treated dialysis patients, this epidemiologic stu dy compared cause of death in prevalent HD- and PD-treated patients in a large national sample, adjusting for demographic characteristics, D ata for patients prevalent on January 1 of the years 1987, 1988, and 1 989, each with 1 yr of follow-up, were obtained from the U.S. Renal Da ta System. Patients were censored at transplantation. Death rates per 100 patient years for seven cause-of-death categories were compared be tween HD and PD, adjusting for age, race, gender, cause of ESRD (diabe tes versus nondiabetes), and < 1 yr or > 1 yr of prior ESRD, by use of the Poisson regression. There were 42,372 deaths occurring over 170,7 00 patient years at risk. There was a significantly increased mortalit y risk for PD compared with HD for all cause-of-death categories, exce pt malignancy, for which there was a higher mortality risk for HD. The excess all-cause mortality observed in PD-treated patients can be acc ounted for, in decreasing order, by infection (35%), acute myocardial infarction (24%), other cardiac causes (16%), cerebrovascular disease (8%), withdrawal (8%), and malignancy (-6%). The increased risk of dea th due to ''other cardiac causes'' and withdrawal from dialysis in PD- treated patients was found only among diabetics, and the increased ris k due to acute myocardial infarction was accentuated among diabetics. The increased risk of death due to infection was accentuated in female patients. The PD/HD risk ratio of death increased with age for the ca tegory ''other cardiac causes'' and cerebrovascular disease, whereas i t decreased with age for deaths due to withdrawal from dialysis.