The new UK national kidney allocation scheme with maximized “R4-D4” kidney transplants: better patient-to-graft longevity matching may be at the cost of more resources

Pearson, R., Murray, E. , Thomson, P. C., Mark, P. B. , Clancy, M. J. and Asher, J. (2021) The new UK national kidney allocation scheme with maximized “R4-D4” kidney transplants: better patient-to-graft longevity matching may be at the cost of more resources. Experimental and Clinical Transplantation, 19(11), pp. 1133-1141. (doi: 10.6002/ect.2021.0129) (PMID:34812704)

Abstract

Objectives: A new kidney matching scheme for allocation of deceased donor kidneys for transplan­tation was introduced in the United Kingdom in September 2019. Donors and recipients are stratified into quartiles derived from demographic and retrieval indices associated with risk of adverse outcome. We present data on 2 years of transplants, with the aim of understanding the potential impacts of the scheme on patient/transplant outcomes, hospitalization, and resource utilization. Materials and Methods: All deceased donor transplants from 2015 and 2016 were reclassified using the risk quartiles (D1-D4 for donor and R1-R4 for recipient, where 4 is highest risk). Inpatient length of stay, kidney function defined by estimated glomerular rate at 1 year, and patient survival data were collected. Results: Of the 195 deceased donor transplants analyzed, 144 recipients (73.4%) were in the highest risk R4 category, including 55 with R4-D4 combination (28.1%). Recipients in the R4 category had longer index admissions (mean of 12.4 vs 8.1 days for R1-R3; P = .002) and higher subsequent admission rates 90 days posttransplant (185.7 vs 122.7/1000 patient days for R1-R3; P < .001). Kidney transplant function at 1 year was lower for grafts categorized as D4 (mean estimated glomerular filtration rate of 35.7 vs 54.8 mL/min/1.73 m2 for D1-D3; P < .001). However, survival for R4 recipients with D4 kidneys was not significantly different from R4 recipients with D1 to D3 kidneys (4-year patient survival rate with R4-D4 combination was 90.9%). Conclusions: The principles of the allocation scheme in matching graft and patient survival were already largely being observed (matching higher risk deceased donor kidneys to higher risk recipients). However, an increase in D4 proportions in the R4 group may be associated with longer hospitalization posttransplant. Consideration should be given to mitigation strategies to address this. Despite poorer graft function, patient survival appears satisfactory.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Murray, Dr Eleanor and Thomson, Dr Peter and Clancy, Mr Marc and Mark, Professor Patrick and Pearson, Robert
• Authors: Pearson, R., Murray, E., Thomson, P. C., Mark, P. B., Clancy, M. J., and Asher, J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Experimental and Clinical Transplantation
• Publisher: Middle East Society for Organ Transplantation
• ISSN: 1304-0855
• ISSN (Online): 2146-8427
• Published Online: 01 November 2021