Trends in Epidemiologic Characteristics and Clinical Patterns of Vascular Access of Incident Hemodialysis Patients: Nationwide Cohort Study (2006-2019) in Korea

Background: The number of patients with end-stage kidney disease (ESKD) undergoing hemodialysis (HD) was rapidly growing in Korea. Although there was a Korean Renal Dialysis System (KORDS) registry for analyzing HD practice patterns in Korea, the registration rate (63.8% in 2022) wasn't sufficient to represent real-world aspects. Thus, we analyzed HD patients' clinical practice patterns in Korea using National Health Insurance System (NHIS) data. Methods: Subjects were extracted from NHIS data, comprising patients with code V001 for financial support in rare incurable patients (i.e., ESKD) and code O70102 for HD from 2006 to 2019. We examined epidemiological characteristics and practice patterns of vascular access in initiated HD patients. We defined the central venous catheter (CVC) user to the presence of O7012, CVC-related code for the charge of the Health Insurance Service Procedure 6 months before encoding the HD-related code, and the arteriovenous (AV) access user to the presence of AVF-related codes (O2083, O2056, O2081, O2082, O2083, and O2059) 6 months before encoding the HD-related code. Results: Patients initiating HD surged from 4,927 in 2006 to 14,049 in 2019. The proportion of those aged 70-79 and above 80 rose from 10% and 1% in 2006 to 25% and 18% in 2019, respectively. CVC usage increased from 43% in 2006 to 54% in 2019, while AV access rose from 15% to 28%. Especially in the 60-79 age group, AV access users increased significantly (from 5% in 2006 to 15% in 2019). The mean duration after AV access creation before usage increased (from 2.3 months in 2006 to 3.6 months in 2019). Conclusion: The trends in epidemiologic characteristics showed similarities compared to the KORDS registry. However, clinical patterns of vascular access in HD initiation differed. Our report might help represent real-world aspects in ESKD patients who have started HD.