Scientific Publications Database
Article Title: Is the Kidney Donor Risk Index a Useful Tool in Non-US Patients?Authors: Young, Ann; Knoll, Greg A; McArthur, Eric; Dixon, Stephanie N; Garg, Amit X; Lok, Charmaine E; Lam, Ngan N; Kim, S Joseph
Journal: Canadian journal of kidney health and disease Volume 5
Date of Publication:2018
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.CONTEXTE: Aux Etats-Unis, lattribution des reins provenant de donneurs decedes est guidee par lindice Kidney Donor Risk Index (KDRI). La generalisation de cet indice hors des Etats-Unis a toutefois ete peu etudiee.OBJECTIF DE LETUDE: Determiner sil est possible de generaliser lindice KDRI a une cohorte canadienne de receveurs dun rein provenant dun donneur decede.TYPE DETUDE: Il sagit dune etude de cohorte retrospective.CADRE: La province de lOntario, au Canada.SUJETS: Les patients ayant recu un rein provenant dun donneur decede entre le 1er janvier 2005 et le 31 mars 2011.METHODOLOGIE: A laide des donnees administratives provinciales de lOntario (Canada), nous avons analyse une cohorte de receveurs dun rein provenant dun donneur decede. Des modeles des risques proportionnels de Cox et la methode de Kaplan-Meier ont ete employes pour quantifier la relation entre lindice KDRI et le risque de perte du greffon ou de deces du patient. Lindice KDRI a ete modelise de facon continue et par quintiles. On a egalement etudie la validite predictive des modeles employant lindice KDRI concernant les resultats du receveur au-dela dune prediction basee uniquement sur lage du donneur. Le pouvoir discriminant des modeles a ete analyse par la surface sous la courbe a cinq ans post-intervention.RESULTATS: Un total de 1299 receveurs dune greffe de rein provenant dun donneur decede ont ete inclus dans letude. La duree mediane du suivi setablissait a 5,5 ans. Lage moyen des donneurs passait de 27 ans au quintile inferieur a 64 ans au quintile superieur. Le risque relatif corrige (IC 95 %) de perte totale du greffon du Q2 au Q5 (reference = Q1) setablissait respectivement a 1,27 (0,89; 1,80), 1,58 (1,13; 2,22), 1,43 (1,01; 2,02), et 2,15 (1,54; 2,99). Une augmentation du risque relatif a egalement ete observee pour tous les quintiles dans les cas de perte du greffon censuree au deces du patient, mais pas dans les cas de deces du patient dont le greffon etait toujours fonctionnel. Le taux de mortalite toutes causes confondues sest accru dans le quintile superieur seulement. Au sein de cette cohorte, le modele base sur lindice KDRI a mieux predit lissue des patients que le modele base uniquement lage du donneur (p=0,009).LIMITES DE LETUDE: Vu la grande taille des bases de donnees en sante, il est possible que la saisie des covariables soit incomplete.CONCLUSION: Lindice KDRI est generalisable aux patients ontariens et pourrait contribuer a eclairer levaluation des risques plus efficacement quen ne considerant que lage du donneur. La valeur predictive de lindice KDRI hors des Etats-Unis et la necessite de perfectionner le modele justifient des etudes plus approfondies.