A nationwide study of regional preference and graft survival of kidney transplantation in South Korea: patterns of centralization in the capital area

Abstract

Purpose: This study aims to investigate regional patterns and graft survival rates in kidney transplantation (KT) within South Korea using the National Health Insurance Service database.

Methods: By analyzing KT data from 2002 to 2017, including patient residency, KT location, and post-KT dialysis information, graft survival was assessed through post-KT dialysis and validated against Ulsan University Hospital and the Korean Organ Transplantation Registry's 2017 report.

Results: Among the 20,978 KTs, 60.5% occurred in the Korean capital, Seoul, whereas 39.5% occurred outside. The overall graft survival rate was 81.5% with a median survival duration of 57 months. Patient survival was 83.8%, with a median survival duration of 61 months. For KTs from 2002 to 2007, the 10-year graft and patient survival rates were 89.1% and 90.3%, respectively. The KT recipients living outside Seoul who underwent the KT within their residential regions had a graft survival rate of 88.3%, and those receiving KTs outside their original region had a graft survival rate of 88.0%. Among Seoul residents who underwent KTs in the city, the graft survival rate was 90.5%. Importantly, hospital location did not significantly affect graft survival rates (P = 0.136).

Conclusion: This study revealed a regional preference for KT in South Korea, particularly in the capital city, likely because of nonresidents. Nevertheless, the graft and patient survival rates showed no significant regional disparities. These findings emphasize the necessity for equitable KT service access across regions in order to optimize patient outcomes.

Keywords: Big data; Graft survival; Kidney transplantation; Survival.

Fig. 1. Cumulative kidney transplantation numbers in major South Korean metropolitan cities (2002–2017).

Fig. 2. Kidney transplantation (KT) numbers in major South Korean metropolitan cities (2002–2017), categorized by hospital region and patient residence (per million population). (A) Kidney transplantations per million population, categorized by hospital region (2002–2017). (B) Kidney transplantations per million population, categorized by patient residence (2002–2017).

Fig. 3. Kaplan-Meier plots for 10-year graft survival after kidney transplantations performed from 2002 to 2007. (A) Ten-year graft survival after kidney transplantations between 2002 and 2007. (B) Ten-year graft survival categorized by residence. (C) Ten-year graft survival for both Seoul and non-Seoul major cities, categorized by residence.