A Cost-Effectiveness Analysis of Gemcitabine plus Cisplatin Versus Gemcitabine Alone for Treatment of Advanced Biliary Tract Cancer in Japan

OBJECTIVES: This study assessed the cost-effectiveness of combination treatment with gemcitabine and cisplatin compared to treatment with gemcitabine alone for advanced biliary tract cancer (BTC) in Japan. METHODS: A monthly transmitted Markov model of three states was constructed based on the Japan BT-22 trial. Transition probabilities among the health states were derived from a trial conducted in Japan and converted to appropriate parameters for our model. The associated cost components, obtained from a receipt-based survey undertaken at the Aichi Medical University Hospital, were those related to inpatient care, outpatient care, and treatment for BTC. Costs for palliative care and treatment of adverse events were obtained from the National Health Insurance price list. We estimated cost-effectiveness per quality-adjusted life year (QALY) at a time horizon of 36 months. An annual discount of 3 % for both cost and outcome was considered. RESULTS: The base case outcomes indicated that combination therapy was less cost-effective than monotherapy when the incremental cost-effectiveness ratio (ICER) was approximately 14 million yen per QALY gained. The deterministic sensitivity analysis of the ICER revealed that the ICER of the base case was robust. A probabilistic analysis conducted with 10,000-time Monte Carlo simulations demonstrated efficacy at the willingness to pay threshold of 6 million yen per QALY gained for approximately 33 % of the population. CONCLUSION: In Japan, combination therapy is less cost-effective than monotherapy for treating advanced BTC, regardless of the statistical significance of the two therapies. Useful information on the cost-effectiveness of chemotherapy is much needed for the treatment of advanced BTC in Japan.