Comparison of mortality in all patients on dialysis, patients on dialysis awaiting transplantation, and recipients of a first cadaveric transplant.

Background: The extent to which renal allotransplantation -- as compared wi th long-term dialysis -- improves survival among patients with end-stage re nal disease is controversial, because those selected for transplantation ma y have a lower base-line risk of death. Methods: In an attempt to distinguish the effects of patient selection from those of transplantation itself, we conducted a longitudinal study of mort ality in 228,552 patients who were receiving long-term dialysis for end-sta ge renal disease. Of these patients, 46,164 were placed on a waiting list f or transplantation, 23,275 of whom received a first cadaveric transplant be tween 1991 and 1997. The relative risk of death and survival were assessed with time-dependent nonproportional-hazards analysis, with adjustment for a ge, race, sex, cause of end-stage renal disease, geographic region, time fr om first treatment for end-stage renal disease to placement on the waiting list, and year of initial placement on the list. Results: Among the various subgroups, the standardized mortality ratio for the patients on dialysis who were awaiting transplantation (annual death ra te, 6.3 per 100 patient-years) was 38 to 58 percent lower than that for all patients on dialysis (annual death rate, 16.1 per 100 patient-years). The relative risk of death during the first 2 weeks after transplantation was 2 .8 times as high as that for patients on dialysis who had equal lengths of follow-up since placement on the waiting list, but at 18 months the risk wa s much lower (relative risk, 0.32; 95 percent confidence interval, 0.30 to 0.35; P<0.001). The likelihood of survival became equal in the two groups w ithin 5 to 673 days after transplantation in all the subgroups of patients we examined. The long-term mortality rate was 48 to 82 percent lower among transplant recipients (annual death rate, 3.8 per 100 patient-years) than p atients on the waiting list, with relatively larger benefits among patients who were 20 to 39 years old, white patients, and younger patients with dia betes. Conclusions: Among patients with end-stage renal disease, healthier patient s are placed on the waiting list for transplantation, and long-term surviva l is better among those on the waiting list who eventually undergo transpla ntation. (N Engl J Med 1999;341:1725-30.) (C)1999, Massachusetts Medical So ciety.