Factors affecting the waiting time of cadaveric kidney transplant candidates in the United States.

OBJECTIVE--To evaluate the relative impact of various factors that could account for differences in waiting time of cadaveric kidney transplant candidates (eg, black and sensitized patients). DESIGN.--A cohort study using multivariate analyses to identify associations between 36 patient, donor, and center factors with waiting time for all US cadaveric kidney transplant candidates listed between October 1, 1987, and June 30, 1990. SETTING--All US kidney transplant centers. PATIENTS--The study included 23,468 cadaveric renal transplant candidates on active waiting status. RESULTS--The patient characteristics most significantly associated with increased waiting time (adjusted for all other variables) were immunologic and included presensitization to HLA antigens, O or B blood type, candidacy for a repeat transplantation, and expression of rare HLA-A or HLA-B antigen phenotypes. Nonimmunologic factors also affected waiting times, which were significantly shorter for patients younger than 15 years vs those aged 15 through 44 years (8.4 vs 12.9 months, respectively; P less than .0001), for those listed at multiple centers vs one center (7.0 vs 13.3 months, respectively; P less than .0001), or for white vs black patients (11.9 vs 15.4 months, respectively; P less than .0001). Local transplant center characteristics associated with a significantly shorter waiting time included a small number of transplantation candidates, a high (greater than 35 per million population) local kidney organ recovery rate, and an approved variance from the Organ Procurement and Transplantation Network allocation algorithm. CONCLUSIONS--The time renal transplant candidates must wait for kidney transplantation is influenced by several factors in addition to those expected due to immunologic reasons of donor incompatibility, the algorithms used for organ distribution, or the effectiveness of local kidney recovery. The impact of these factors should be considered as the current US system for allocating scarce donor organs for kidney transplantation is modified.