Mycophenolate mofetil is associated with less death with function than azathioprine in cadaveric renal transplantation

Background. A previous study has argued that mycophenolate mofetil (MMF) is associated with a reduced incidence of death with function when compared to azathioprine (AZA) in cadaveric renal transplantation. This study was designed to verify this result because methodological issues bring these findings into question. Methods. The data used in this study was derived from records of renal transplants performed in 1995 and 1996 as recorded in the UNOS Scientific Renal Transplant Registry and supplied by the United States Renal Data System (USRDS). Univariate and multivariate survival analysis was used to compare rates of death with function. Covariate characteristics of the donor, recipient, procedures, early outcomes and the transplant centre were considered. Results. 12 251 recipients of cadaveric renal transplants were identified as having received either MMF or AZA, but not both. The relative risk of death with function calculated by the Kaplan-Meier method was 21% less for MMF patients (P = 0.005). MMF had from 21% (P = 0.008) to 24% (P = 0.001) reductions in relative risk by multivariate methods. Conclusions. The use of MMF is associated with a reduction in the incidence of death with a functioning graft in cadaveric renal transplantation. These results verify previous analyses.