Cost-effectiveness of the GAAD algorithm for hepatocellular carcinoma surveillance of patients with compensated cirrhosis: a model-based analysis using Italian real-world data

Aims: Early detection of hepatocellular carcinoma (HCC) in patients with compensated cirrhosis (CC) is critical for improving prognosis. The GAAD algorithm (gender [biological sex], age, alpha-fetoprotein [AFP], protein induced by vitamin K absence-II [PIVKA-II]) demonstrated good performance for the detection of early-stage HCC. This study aimed to assess the cost-effectiveness of the GAAD algorithm for HCC surveillance in patients with CC in Italy, from the Italian Health Service perspective. Methods: A probabilistic micro-simulation Markov model was adapted to the Italian context to estimate lifetime clinical outcomes and costs of CC patients undergoing bi-annual surveillance with ultrasound (US), US+AFP, GAAD, and US+GAAD. Clinical inputs and utility values were derived from Italian real-world data and published literature. Direct healthcare costs were collected from Italian sources. Costs and outcomes were discounted at an annual 3% rate. Sensitivity analyses were conducted to evaluate the uncertainties in input parameters. Results: In a simulated cohort of 100,000 CC patients, QALYs and costs per patient were 6.53 and €35,524 for US, 6.56 and €35,825 for US+AFP, 6.57 and €35,423 for GAAD, and 6.58 and €35,939 for US+GAAD. Compared to US and US+AFP, GAAD was dominant, while US+GAAD was cost-effective (ICUR of €9,482 and €10,951 per QALY gained, respectively). At a willingness-to-pay threshold of €30,000, GAAD was the most cost-effective strategy. Sensitivity analyses confirmed the robustness of results. Limitations: Assumptions were required to estimate the diagnostic performance of US+GAAD, given the absence of prospective validation data. Some clinical parameters were derived from non-Italian sources, which may limit generalizability. Conclusion: GAAD, alone or combined with US, is a cost-effective strategy for HCC surveillance in CC patients in Italy, improving the detection of early-stage disease. Better performance data for US+GAAD is needed to confirm results.