NATIONAL KIDNEY ALLOGRAFT SHARING - A DECISION-ANALYSIS

Background. Expansion of the current program of national sharing of ca daveric kidney allografts is of uncertain benefit, and the logistical barriers to expanding organ sharing are large. This study estimated th e improvement in allograft survival from expanding organ sharing in th e United States. Methods. A decision analysis based on allograft survi val data from cadaveric allograft recipients throughout the United Sta tes compared the mean allograft survival resulting from four allograft -sharing strategies: no national sharing, national sharing of allograf ts matched at 6 histocompatibility alleles, national sharing of allogr afts matched at 4 or more alleles, and national sharing of allografts matched at 2 or more alleles. Results. Sharing allografts matched at 4 or more alleles was optimal (mean allograft survival=6.35 years). Thi s survival was little better than the mean survival of the other three strategies (no national sharing, 6.21 years; national sharing of allo grafts matched at 6 alleles, 6.31 years; and sharing of allografts mat ched at 2 or more alleles, 6.33 years). The increment in the proportio n of allografts surviving 4 years or more under the optimal strategy c ompared with no national sharing was <2%. A similar decision model com paring kidney transplant outcomes before and after the introduction of cyclosporine showed that this drug has had a much greater impact on m ean allograft survival than would be expected to occur with national a llograft sharing: 6.07 years with cyclosporine versus 3.79 years witho ut cyclosporine. Conclusions. Expanding national allograft sharing wou ld achieve little improvement in mean allograft survival. The limited benefit and logistical barriers to expansion of allograft sharing shou ld be considered before following recommendations to expand the curren t U.S. allograft-sharing program.