Disparities in Acceptance of Deceased Donor Kidneys Between the United States and France and Estimated Effects of Increased US Acceptance

Abstract

Importance: Approximately 3500 donated kidneys are discarded in the United States each year, drawing concern from Medicare and advocacy groups.

Objective: To estimate the effects of more aggressive allograft acceptance practices on the donor pool and allograft survival for the population of US wait-listed kidney transplant candidates.

Design, setting, and participants: A nationwide study using validated registries from the United States and France comprising comprehensive cohorts of deceased donors with organs offered to kidney transplant centers between January 1, 2004, and December 31, 2014. Data were analyzed between September 1, 2018, and April 5, 2019.

Main outcomes and measures: The primary outcome was kidney allograft discard. The secondary outcome was allograft failure after transplantation. We used logistic regression to model organ acceptance and discard practices in both countries. We then quantified using computer simulation models the number of kidneys discarded in the United States that a more aggressive system would have instead used for transplantation. Finally, based on actual survival data, we quantified the additional years of allograft life that a redesigned US system would have saved.

Findings: In the United States, 156 089 kidneys were recovered from deceased donors between 2004 and 2014, of which 128 102 were transplanted, and 27 987 (17.9%) were discarded. In France, among the 29 984 kidneys recovered between 2004 and 2014, 27 252 were transplanted, and 2732 (9.1%, P < .001 vs United States) were discarded. The mean (SD) age of kidneys transplanted in the United States was 36.51 (17.02) years vs 50.91 (17.34) years in France (P < .001). Kidney quality showed little change in the United States over time (mean [SD] kidney donor risk index [KDRI], 1.30 [0.48] in 2004 vs 1.32 [0.46] in 2014), whereas a steadily rising KDRI in France reflected a temporal trend of more aggressive organ use (mean [SD] KDRI, 1.37 [0.47] in 2004 vs 1.74 [0.72] in 2014; P < .001). We applied the French-based allocation model to the population of US deceased donor kidneys and found that 17 435 (62%) of kidneys discarded in the United States would have instead been transplanted under the French system. We further determined that a redesigned system with more aggressive organ acceptance practices would generate an additional 132 445 allograft life-years in the United States over the 10-year observation period.

Conclusions and relevance: Greater acceptance of kidneys from deceased donors who are older and have more comorbidities could provide major survival benefits to the population of US wait-listed patients.

Trial registration: ClinicalTrials.gov identifier: NCT03723668.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Reese reported investigator-initiated grants from Merck and AbbVie to the University of Pennsylvania to support research on transplantation of hepatitis C–infected organs into uninfected recipients, followed by antiviral treatment, investigator-initiated grants from CVS Caremark and Merck to the University of Pennsylvania to support research on medication adherence, consulting with Collaborative Healthcare Research & Data Analytics (COHRDATA) on epidemiology of medications to improve laboratory parameters including potassium among dialysis patients, and position as associate editor for the American Journal of Kidney Diseases. Dr Legendre reported personal fees from Alexion and personal fees from CSL Behring outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Deceased Donor Kidneys Transplanted and Discarded in the United States and France Between 2004 and 2014 and Their Kidney Donor Risk Index (KDRI) Scoresa

Data are based on 156 089 recovered kidneys in the United States, including 128 102 transplanted and 27 987 discarded kidneys, and on 29 984 recovered kidneys in France, including 27 252 transplanted and 2732 discarded kidneys. A, The distribution of KDRI scores for transplanted (blue) and discarded (orange) kidneys in the United States. B, The distribution of the KDRI score for transplanted (blue) and discarded (orange) kidneys in France. Dashed vertical lines correspond to the mean KDRI of transplanted kidneys (dashed blue) and discarded (dashed orange) kidneys. C, The probability of discard in the United States by KDRI; and D, The probability of discard in France by KDRI. The blue curve corresponds to the probability of discard according to the KDRI in the United States (C) and in France (D). aLower KDRI indicates better kidney quality.

Figure 2.. Number of Actually Transplanted and Discarded Kidneys in the United States Contrasted With the Number of Kidneys That Would Have Been Saved and Discarded Using a Redesigned System

The number of actually transplanted and discarded kidneys in the United States between 2004 and 2014 and the kidneys that would have been transplanted and discarded if the French model had been applied in the United States. The blue line shows the number of kidneys that would have been saved in the United States if the French model had been applied. Overall, a total of 17 435 US kidneys would have been saved during the observation period.

Figure 3.. Estimation of the Allograft Life-Years Gained From Reducing Kidney Discard Rates in the United States Through a Redesigned System

KDRI Indicates Kidney Donor Risk Index. The greatest gain in life-years is achieved through reduced discard of the lowest-quality kidneys. A, The life-years saved by decile of the Kidney Donor Risk Index (KDRI) by applying French acceptance-based patterns to the pool of US kidneys. B, The life-years saved overall if organ acceptance patterns in the United States had followed the French acceptance model.