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.

Prevalence and treatment of decreased bone density in renal transplant recipients: a randomized prospective trial of calcitriol versus alendronate.

BACKGROUND: Reduced bone mineral density (BMD) is common in long-term renal transplant recipients and results in a high incidence of fractures. The optimal therapy for these patients is not known. METHODS: Baseline BMD determinations were obtained in 211 long-term adult renal transplant recipients. One hundred and seventeen patients with a reduced BMD (T score < or = -1) were randomly assigned to treatment with alendronate and calcium (n=60) versus calcitriol and calcium (n=57). Of these, 46 and 51 patients, respectively, completed 1 year of treatment. Forty-nine patients who were not eligible or did not consent to the trial were followed prospectively. RESULTS: Reduced baseline BMD (T score < or = -1) was present in 159 (78.7%) of patients at the lumbar spine or femur. There was no significant loss of BMD in the prospectively followed patients during 2.7 years. The average lumbar BMD increased from 0.984+/-0.149 to 1.025+/-0.143 g/cm2 (P<0.001) with alendronate and from 1.014+/-0.15 to 1.034+/-0.146 g/cm2 (P=0.002) with calcitriol. BMD at the femur increased from 0.809+/-0.092 to 0.836+/-0.107 g/cm2 (P<0.001) with alendronate and from 0.830+/-0.144 to 0.857+/-0.125 g/cm2 (P=0.023) with calcitriol. CONCLUSIONS: One year of treatment with alendronate or calcitriol, both with calcium supplementation, resulted in significant increases in BMD at the lumbar spine and femur, with a trend toward alendronate being more effective at the spine (P=0.082). Further studies are needed to determine whether BMDs continue to increase after 1 year and whether there is any additional benefit to combining vitamin D and alendronate. Larger studies are needed to determine whether treatment decreases fracture rates.

Trends in mortality and graft failure for renal transplant patients.

BACKGROUND: Several important advances in general medical management both before and after renal transplantation have occurred over the last 5-15 years, however, few studies have formally examined trends in the outcomes of renal transplantation. We, therefore, aimed to determine the degree to which these advances have resulted in improved outcomes such as survival of patient and graft. METHODS: We analyzed the rates of death and graft failure among the 11,482 Canadians with end-stage renal disease who received a kidney transplant in 1981-98. Patients were followed from the date of transplantation to the date of graft failure, the date of death or the end of the observation period, namely, Dec. 31, 1998, depending on which was the earliest. Rate ratios for mortality and graft failure--ratios of the rate for each calendar period to the rate for the arbitrarily chosen reference period, 1981-85--were estimated with a piece-wise exponential model that adjusted for age, sex, ethnicity, primary renal diagnosis, follow-up time and donor-organ source. RESULTS: The rates and adjusted rate ratios for death and graft failure decreased significantly and steadily over time. Relative to 1981-85, the adjusted mortality rate ratios were 0.70 (95% confidence interval [CI] 0.54-0.89), 0.65 (95% CI 0.52-0.82) and 0.53 (95% CI 0.41-0.67) for 1986-89, 1990-94 and 1995-98 respectively, and the adjusted graft failure rate ratios were 0.68 (95% CI 0.60-0.78), 0.62 (95% CI 0.54-0.70) and 0.51 (95% CI 0.44-0.58) respectively. The decrease was mostly among the cadaveric-organ recipients. Calendar period was as important a predictor of outcome as well-known prognostic factors such as age and primary renal diagnosis. INTERPRETATION: Decreases in mortality rates are probably related to refinements in patient management. Decreases in graft failure rates are probably the result of a combination of improved immunotherapy and better management of nonimmunologic conditions such as hypertension and hyperlipidemia.