Regional variation in kidney transplant outcomes: trends over time.

Background And Objectives: Clinical outcomes after kidney transplant have improved considerably in the United States over the past several decades. However, the degree to which this has occurred uniformly across the country is unknown.

Design, Setting, Participants, & Measurements: Regional variations in graft failure after kidney transplant during three different time periods were examined. These time periods were chosen to coincide with major shifts in immunosuppressant usage: Era 1, cyclosporine usage, 1988 through 1989; Era 2, introduction of tacrolimus and mycophenolate mofetil, 1994 through 1995; and Era 3, widespread use of tacrolimus and mycophenolate mofetil, 1998 through 1999. Patient data were obtained from the United States Renal Data System database. For each period, regional differences in time from transplant to graft failure (organ removal, death, or return to dialysis) were examined. For each region, differences in graft failure over time were examined.

Results: One-year graft survival rates ranged from 76% to 83% between regions in Era 1 (n = 13,669), from 84% to 89% in Era 2 (n = 17,456), and from 87.5% to 92% in Era 3 (n = 20,375). Three-year graft survival ranged from 65% to 75% between regions in Era 1, from 84% to 89% in Era 2, and from 77% to 86% in Era 3. Adjusted models for donor and recipient characteristics showed improvements in graft survival over time in all United Network for Organ Sharing regions with minimal variation across regions.

Conclusions: Regional differences in graft survival after kidney transplant are minimal, particularly when compared with the dramatic improvements in graft survival that have occurred over time.