Centre-specific variation in renal transplant outcomes in Canada.

BACKGROUND: The 'centre effect' has accounted for significant variation in renal allograft outcomes in the United States and Europe. To determine whether similar variation exists in Canada, we analysed mortality and graft failure (GF) rates among Canadian end-stage renal disease patients who received a renal allograft from 1988 to 1997 (n = 5082) across 20 transplant centres.
METHODS: Patients were followed from the date of transplantation to the time of GF and/or death. A Cox proportional hazards model was used to estimate mortality and GF hazard ratios (HRs) adjusted for relevant covariates, including centre volume. Centre-specific HRs were derived by comparing each centre's outcome rates against all others.
RESULTS: Twenty centres were included in the analysis. There was significant centre-specific variation in recipient and transplant characteristics (e.g. age, diabetes mellitus, donor source and centre volume) as well as covariate-adjusted facility-specific outcome rates. Facility-specific HRs for GF (including death with a functioning graft) ranged from 0.51 to 1.77, while mortality HRs (including death beyond GF) showed a similar spread (0.44-1.84). These HRs represent a 3- to 4-fold difference in transplant outcomes among the 20 centres studied. Centres performing less than 200 transplants over the study period were associated with lower graft and patient survival.
CONCLUSIONS: These findings demonstrate significant centre-specific variation in the success of renal transplantation in Canada. Further studies are needed to elucidate the causes of this variation, with the goal of developing strategies to minimize the centre effect and ensure the best possible outcomes for all renal transplant recipients.