PHWR Public Health Weekly Report

Objectives: The Korea hepatitis B cohort study is a prospective cohort established to analyze the epidemiological characteristics and treatment outcomes of individuals with chronic hepatitis B virus (HBV) infection in the Republic of Korea (ROK). This study aims to provide evidence to support HBV control, prevention strategies, and national policy development.
Methods: Adults aged ≥19 years with chronic hepatitis B were enrolled at five regional medical institutions across ROK. Additional blood samples were collected from participants who consented to biospecimens donation. This prospective observational study did not interfere with routine clinical care. Data on antiviral treatment, treatment continuation, and liver-related outcomes, including hepatocellular carcinoma, were collected.
Results: Between 2015 and 2024, a total of 3,221 participants were enrolled in the study. After excluding 422 individuals who were lost to follow-up, clinical data from 2,799 participants were collected. On average, 4.2 longitudinal blood samples per participant were obtained at 6- to 12-month intervals. The cohort exhibited epidemiological patterns consistent with previously reported trends in the ROK. The use of effective antiviral therapy was associated with better management of chronic hepatitis B.
Conclusions: The continuation of this study will enable systematic and efficient monitoring of the current status and long-term clinical outcomes of patients with chronic hepatitis B. These findings are expected to inform revisions of national clinical practice guidelines and support the development of public health policies in the ROK.

Objectives: This study aims to establish national diagnostic reference levels (DRLs) for coronary angiography (CAG) and interventional procedures in the Republic of Korea (ROK), providing objective standards to optimize patient radiation exposure.
Methods: Data were collected from the second through the fourth quarter of 2024 from 20 certified medical institutions. A total of 1,980 cases involving seven major procedures—including CAG, percutaneous coronary intervention ( PCI), and chronic total occlusion (CTO) procedure were analyzed. Using digital imaging and communications in medicine ( DICOM) radiation dose structured reports (RDSRs) and procedure reports, the dose area product (DAP) and fluoroscopy time (FT) were evaluated. The DRLs were defined as the 75th percentile of the dose distributions.
Results: CTO showed highest values with a DAP of 106.83 Gy‧cm² and an FT of 2,819.00 seconds, reflecting high procedural complexity. In contrast, diagnostic CAG showed the lowest values with a DAP of 18.68 Gy‧cm² and an FT of 440.00 seconds. The DAP and FT for combined CAG+PCI was 63.40 Gy‧cm² and 1,201.50 seconds. Overall, the derived Korean DRLs were generally lower than those reported in major developed countries.
Conclusions: This study presents the first national DRLs for cardiac interventional procedures in the ROK based on multicenter clinical data. These findings provide a foundational baseline for the management of radiation safety and dose optimization in clinical practice.