Survival improvement among patients with end-stage renal disease: trends over time for transplant recipients and wait-listed patients

Abstract

Both transplant and dialysis outcomes have improved over recent years. In addition, transplantation has been shown to confer a survival benefit over maintenance dialysis. The study presented here addresses the question of whether the survival benefit of transplantation over maintenance dialysis has changed in the most recent eras. This study was based on data collected by the United States Renal Transplant Scientific Registry and the United States Renal Data System. The study sample consisted of 104,000 patients placed on the renal transplant waiting list between 1988 and 1996, of which 73,707 subsequently received renal transplants. The annualized adjusted mortality rates per 1000 patient-years were calculated by calendar year of placement on the renal transplant waiting list and for kidney transplant recipients. The resulting data were plotted, and linear curve fitting was used to estimate the slope of the change of the adjusted mortality rates by year during the period studied, 1988 to 1996. Overall annual adjusted death rates in the wait-listed patients and transplant recipients per 1000 patient-years decreased for both groups throughout the study period. From 1989 to 1996, the relative risk (RR) for patient death had decreased by 30% for transplant recipients and 23% for wait-listed patients (RR = 0.70 and 0.77; P < 0.0001 each). Slope analysis of the cause-specific mortality rates for cardiovascular disease and infection showed nearly equivalent, linear decreases for both groups. Mortality rates have improved overall and by categories of major cause of death for both renal transplant recipients and patients on the renal transplant waiting list. These favorable trends most likely represent equal advances in transplantation, dialysis, and general medical care.