Hepatitis C Core Antigen test as an alternative for diagnosing HCV infection: mathematical model and cost-effectiveness analysis

Abstract

Background: The cost and complexity of polymerase chain reaction (PCR) testing is a significant barrier for the diagnosis and treatment of patients infected with hepatitis C virus (HCV). We investigated the cost-effectiveness of various testing strategies using antigen as an alternative to PCR. Methods: We developed a mathematical model for HCV to estimate the number of newly diagnosed individuals and cases of different stages of liver disease. We compared the following testing strategies: antibody test followed by PCR in case of positive antibody (baseline strategy); antibody test followed by HCV-antigen test (antibody-antigen); antigen test alone; and PCR test alone. We conducted cost-effectiveness analyses considering the costs of HCV testing (of both infected and uninfected individuals) (A1), liver-related complications (A2) and all costs including HCV treatment (A3). The model was parameterized for the country of Georgia, and several sensitivity analyses were conducted to generalize the findings for different settings. Results: Using the current standard of testing, 89% of infected individuals were detected. Comparatively, antibody-antigen and antigen testing alone detected 86% and 88% of infected individuals, respectively. PCR testing alone detected 91% of the infected individuals with the remaining 9% dying or spontaneously recovering before testing. In analysis A1, antibody-antigen testing was not found to be essentially cheaper compared to the baseline strategy. In analysis A2, strategies using PCR were cheaper than antigen-based strategies. In analysis A3, antibody-antigen testing was the cheapest strategy, followed by the baseline strategy, and PCR testing alone. Conclusion: Antigen testing, either following a positive antibody test or alone, performed almost as well as the current practice of HCV testing. The cost-effectiveness of these strategies strongly depends on the inclusion of treatment costs.