Optimizing hepatitis C micro-elimination in forensic psychiatric settings: Cost-effectiveness of screening strategies in Korea.

BACKGROUND: Forensic psychiatric facilities in South Korea represent a critical but overlooked venue for hepatitis C virus (HCV) micro-elimination among people who inject drugs. This study evaluated the cost-effectiveness and budget impact of various HCV screening and treatment strategies within this setting. METHODS: We developed a hybrid decision-tree and Markov model to simulate a cohort of admitted patients. Four strategies were compared against the No Screening baseline: Scenario 1 (Universal Screening + Treatment), Scenario 2 (Targeted Screening + Treatment [age ≥40]), and two screening-only variants (Scenarios 3 and 4). The analysis was conducted from a healthcare system perspective over a lifetime horizon. RESULTS: Scenario 1 was a dominant strategy compared to No Screening, reducing liver-related mortality by 76.5% and generating a net lifetime saving of USD 114,562 per cohort. Scenario 2 was also dominant, capturing 94.7% of HCV-positive cases while requiring 28.7% fewer tests. Screening-only strategies provided minimal clinical benefit due to poor linkage-to-care outside the facility. Although Scenario 1 requires a substantial initial investment (USD 332,754 in the first year; USD 973 per individual), the budget impact analysis indicates that this expenditure would be fully offset within 12-14 years through the prevention of advanced liver disease. CONCLUSIONS: Implementing an opt-out "test-and-treat" strategy in forensic psychiatric facilities is highly cost-effective and provides a strategic pathway for HCV elimination. While upfront costs are significant, the long-term clinical and economic returns justify the implementation. Age-targeted screening represents a pragmatic and efficient alternative in resource-constrained settings.