Validation of the KDRI in Korean Deceased Donor Kidney Transplantation

Organ donation in Korea in 2018 and an introduction of the Korea national organ donation system

A total of 1,503 solid organs were procured from 449 deceased donors in 2018. Although the number of donors was down by 12.8% from the previous year (8.7 per million population), the number of organs procured per donor increased from 3.29 in 2017 to 3.35 in 2018. While the causes of brain death by cerebrovascular diseases and head trauma from traffic accidents have declined, brain damage from hypoxia has increased slightly. The most prominent change in the decline of organ donations was a decrease in family consent (36.5% in 2018 vs. 42.9% in 2017). The disagreement over organ donations by other family members even extended beyond the next of kin, and the restriction of organ donations in connection with the suspension of end-of-life care partly affected the consent rate, making this a controversial social issue. An accurate analysis regarding the factors causing the decline of familial consent rates is required, and related organizations along with the government should make a unified concerted effort to resolve this issue. To help achieve this goal, this manuscript describes the transplantation process and briefly explains the Korean domestic organ donation system.

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

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.