Longitudinal Changes in the Effect of Socioeconomic Status on Graft Survival in Kidney Transplantation

Background: Socioeconomic status is recognized as a factor influencing graft survival (GS) in kidney transplant (KT). We evaluated the longitudinal impact of socioeconomic status on GS. Methods: Adult KT alone performed from 2003-2013 were evaluated using the United Network for Organ Sharing database. The period of post-transplantation was divided into 3 categories; Group1: 1-year survival in all patients, Group2: conditional 5-year survival in 1 year-survivors, Group3: conditional 10-year survival in 5-year survivors. We explored the influence of socioeconomic status on long-term GS in living donor KT (LDKT) and deceased donor KT (DDKT), focusing on two domains: (1) area-level factors, defined by the area deprivation index (ADI); and (2) individual-level factors, including patients’ income, education level. Results: In total, 186,342 adult KT were performed from 2003-2013 (Group1), of which 176,656 recipients survived at 1 year (Group2) and 126,405 recipients survived at 5 years (Group3) post-transplant. In DDKT, the most deprived area (ADI 71-100) was associated with worse GS only in the latest period, compared to the least deprived area (ADI 0-25). In contrast, in LDKT, patients residing in the most deprived areas was linked to poorer GS across all post-transplant periods(Fig.1). Lower education level was associated with worse GS only in the later post-transplant period for both DDKT and LDKT, while employment at the time of transplant was associated with better outcomes throughout (Fig.2). Conclusion: The impact of socioeconomic status on GS changed over time in both DDKT and LDKT. To improve the long-term outcomes, consideration of the education level and areas of residence might be necessary.