Is the Kidney Donor Risk Index a Useful Tool in Non-US Patients?

Abstract

Background:Deceased donor kidney allocation in the United States is guided by the Kidney Donor Risk Index (KDRI). The generalizability of the KDRI beyond the United States has not been widely studied.Objective:To assess the generalizability of the KDRI in a cohort of non-US (Canadian) deceased donor kidney transplant recipients.Design:Population-based retrospective cohort study.Setting:Ontario, Canada.Patients:Recipients of deceased donor kidneys from January 1, 2005, to March 31, 2011.Methods:Using administrative data, we analyzed a cohort of deceased donor kidney recipients in Ontario, Canada. The Kaplan-Meier method and Cox proportional hazards models were used to assess the relationship between KDRI and the outcomes of graft loss and death. KDRI was modeled continuously and categorically. The ability of models with KDRI to predict recipient outcomes beyond donor age was also explored. Model discrimination was assessed using c-statistics, evaluated at 5 years of follow-up.Results:A total of 1299 consecutive deceased donor kidney transplant recipients were included. The median follow-up was 5.5 years. Mean donor age increased from 27 to 64 years across ascending KDRI quintiles. The adjusted relative hazards (95% confidence interval) for total graft loss from Q2 to Q5 (referent = Q1) were 1.27 (0.89-1.80), 1.58 (1.13-2.22), 1.43 (1.01-2.02), and 2.15 (1.54-2.99), respectively. Increased relative hazards across KDRI quintiles were also observed for death-censored graft loss, but not death with graft function. All-cause mortality was increased for the highest KDRI quintile only. In this cohort, a model with KDRI performed better than a model with donor age alone (P = .009).Limitations:Large health care databases may have precluded the complete capture of covariate data.Conclusions:In conclusion, the KDRI is generalizable to Canadian patients in Ontario and may help inform risk assessment beyond donor age. The performance of KDRI in other non-US settings, and the need for additional model refinement, warrants further study.

Predicting Clinical Outcome in Expanded Criteria Donor Kidney Transplantation: A Retrospective Cohort Study

“…The U.S.-developed KDRI was studied in several Canadian populations, including Ontario, BC, and Alberta. [21][22][23] While generalizable, its predictive role above and beyond a smaller number of variables, and specifically, donor age, is not convincing. Inability to observe an association between KDRI and long-term graft outcomes in our study may be related to insufficient power.…”

Kidney Transplantation in Times of Covid-19: Decision Analysis in the Canadian Context

“…Since its derivation using the US Scientific Registry of Transplant Recipients, KDRI has also been studied in several Canadian populations (ie, Ontario, BC, Alberta, and Quebec). [49][50][51][52][53] Two-way sensitivity analyses with 1000 trials and a 10-year horizon were performed to assess how different combinations of recipient, donor, and pandemic characteristics, including emerging SARS-CoV-2 variants, may impact effectiveness and modify the preferred strategy.…”

Non‐standard criteria donors in pediatric kidney transplantation

“…Although some studies show that KDRI is generalizable to non‐US patients, the model needs some refinement . The model has been validated in adult donors but data show that it has limited applicability for pediatric donors …”

“…15 Although some studies show that KDRI is generalizable to non-US patients, the model needs some refinement. 17 The model has been validated in adult donors but data show that it has limited applicability for pediatric donors. 18 Since its implementation in 2014, the KDPI has been central to the kidney allocation system in the United States, with the goal of improving the utility of organs, while reducing differences in transplant access for specific populations, including children.…”