Factors affecting mortality during the waiting time for kidney transplantation: A nationwide population-based cohort study using the Korean Network for Organ Sharing (KONOS) database

Abstract

Background: Long waiting time for deceased donor kidney transplant is inevitable due to the scarcity of donor, resulting in highlighting the importance of waiting time care. We analyzed the Korean Network for Organ Sharing (KONOS) database to assess the impact of waiting time on post-transplant survival outcomes and investigate risk factors for mortality by waiting time based on a complete enumeration survey in Korea.

Methods: We analyzed all persons aged over 18 years in deceased donor kidney transplant cases enrolled in the Korean Network for Organ Sharing (KONOS) database from January 2000 to January 2015. The primary end point was all-cause mortality after enrollment.

Results: Of the 24,296 wait-listed subjects on dialysis, 5,255 patients received kidney transplants from deceased donors, with a median waiting time of 4.5 years. Longer waiting times had distinct deleterious effects on overall survival after transplantation. While waiting for a transplant, patients with diabetes were more likely to die before transplantation (HR 1.515, 95% CI 1.388-1.653, p<0.001). Age was another significant risk factor for mortality. Only 56% of people aged 65 years survived after 10 years of waiting, whereas 86% of people aged 35 years survived after 10 years. Moreover, women on the waiting list were more likely to live longer than men on the list.

Conclusions: More attention should be focused on patients with a higher risk of mortality while waiting for a deceased donor kidney transplant, such as patients with diabetes, those of advanced age, and those who are male.

Fig 1. Kaplan-Meier plots comparing overall survival in patients with deceased donor kidney transplants with those who remained dialysis.

The survival curves were compared using the log rank test (p<0.001).

Fig 2

Cumulative probability to undergo deceased donor kidney transplantation on the waiting list according to age quartile (A), gender (B), ABO blood type (C), Rh blood type (D), cause of ESRD (E), and prior kidney transplant experience (F). Abbreviations: Q1, first quartile, age of 18 to 42; Q2, second quartile, age of 43 to 51; Q3, third quartile, age of 52 to 58; Q4, fourth quartile, age of 59 to 96; PKD, polycystic kidney disease; HTN, hypertension; CGN, chronic glomerulonephritis; DM, diabetic mellitus.