Wolfe R A, Ashby V B, Milford E L, Ojo A O, Ettenger R E, Agodoa L Y, Held P J, Port F K
U.S. Renal Data System Coordinating Center, Department of Biostatistics, University of Michigan, Ann Arbor 48103, USA.
N Engl J Med. 1999 Dec 2;341(23):1725-30. doi: 10.1056/NEJM199912023412303.
The extent to which renal allotransplantation - as compared with long-term dialysis - improves survival among patients with end-stage renal disease is controversial, because those selected for transplantation may have a lower base-line risk of death. In an attempt to distinguish the effects of patient selection from those of transplantation itself, we conducted a longitudinal study of mortality in 228,552 patients who were receiving long-term dialysis for end-stage renal disease. Of these patients, 46,164 were placed on a waiting list for transplantation, 23,275 of whom received a first cadaveric transplant between 1991 and 1997. The relative risk of death and survival were assessed with time-dependent nonproportional-hazards analysis, with adjustment for age, race, sex, cause of end-stage renal disease, geographic region, time from first treatment for end-stage renal disease to placement on the waiting list, and year of initial placement on the list.
Among the various subgroups, the standardized mortality ratio for the patients on dialysis who were awaiting transplantation (annual death rate, 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 was 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 within 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 patients on the waiting list, with relatively larger benefits among patients who were 20 to 39 years old, white patients, and younger patients with diabetes.
Among patients with end-stage renal disease, healthier patients are placed on the waiting list for transplantation, and long-term survival is better among those on the waiting list who eventually undergo transplantation.
与长期透析相比，肾移植在多大程度上能提高终末期肾病患者的生存率存在争议，因为被选作移植的患者可能基线死亡风险较低。为了区分患者选择因素与移植本身的影响，我们对228552例接受终末期肾病长期透析的患者进行了死亡率纵向研究。这些患者中，46164例被列入移植等待名单，其中23275例在1991年至1997年间接受了首次尸体肾移植。采用时间依赖性非比例风险分析评估死亡相对风险和生存率，并对年龄、种族、性别、终末期肾病病因、地理区域、从首次治疗终末期肾病到列入等待名单的时间以及首次列入名单的年份进行了调整。
在各个亚组中，等待移植的透析患者的标准化死亡率（年死亡率为每100患者年6.3例）比所有透析患者（年死亡率为每100患者年16.1例）低38%至58%。移植后前2周的死亡相对风险是自列入等待名单后有相同随访时长的透析患者的2.8倍，但在18个月时风险则低得多（相对风险为0.32；95%置信区间为0.30至0.35；P<0.001）。在我们研究的所有患者亚组中，移植后5至673天内两组的生存可能性变得相等。移植受者的长期死亡率（年死亡率为每100患者年3.8例）比等待名单上的患者低48%至82%，在20至39岁的患者、白人患者以及较年轻的糖尿病患者中获益相对更大。
在终末期肾病患者中，更健康的患者被列入移植等待名单，最终接受移植的等待名单上的患者长期生存率更高。
