A majority of transplant centers had significant improvements in cadaver donor kidney graft survival rates since 1991. A 10% or greater increase in one-year graft survival rates was reported by 36 of 128 large transplant centers. 2. When transplants were grouped according to the organ procurement agency that procured the kidney, large variations in one-year graft survival rates among 65 OPOs were noted. The "OPO effect" was of a magnitude similar to that of the "center effect" when analyzed separately. 3. Fourteen OPOs with the lowest graft survival rates procured a significantly higher fraction of kidneys from older, hypertensive or Black donors and donors whose deaths were not from motor vehicle accidents. Transplants were more often given to Black recipients, and kidneys were less frequently shared compared with 15 OPOs with the highest graft survival rates. 4. Significantly higher proportions of non-Black donors and recipients, patients with no activity limitation at the time of listing, patients working fulltime at the time of transplantation, and patients on dialysis less than one year were more frequently transplanted at 21 centers with excellent one-year graft survival rates compared with centers in groups with poorer results. 5. Increased numbers of mismatched HLA-B,DR antigens were detrimental to graft survival at centers with good or fair one-year graft survival rates, but had a minimal effect at centers with excellent results. 6. The OPO effect on graft survival rates was significantly associated with the center effect. Kidneys procured by OPOs associated with low graft survival rates and transplanted at centers with low graft survival rates resulted in the worst graft outcome. Interestingly, kidneys procured by OPOs associated with high graft survival rates, but transplanted by centers with low graft survival rates had better outcomes than kidneys from OPOs with lower graft survival rates. 7. Based on univariate analyses, the center and OPO effects ranked third and fifth among 16 significant factors. However, after adjusting for these 16 potentially confounding variables using a multivariate Cox regression model, the differences between the best and worst center and OPO groups were the fourth and eleventh most detrimental risk factors on graft outcome, respectively.
