目的 从卫生体系角度出发，评价曲妥珠单抗联合化疗对比单纯化疗治疗HER-2阳性晚期胃癌的成本效果。方法 参考1项Ⅲ期临床试验数据（ToGA研究）构建分区生存模型，通过拟合最佳参数来外推生存曲线模拟患者终生，以质量调整生命年（QALY）来计算增量成本-效果比（ICER），通过单因素敏感性分析和概率敏感性分析验证基础分析结果的稳健性。结果 基础分析结果显示：曲妥珠单抗联合化疗较单纯化疗增加0.19 QALY的同时，需增加成本65 352.42元，大于支付意愿阈值（WTP）。单因素敏感性分析显示：对模型最敏感的3个因素为：无进展生存期（PFS）和进展期（PD）的效用值和曲妥珠单抗的成本。概率敏感性分析显示：当WTP＜320 000.00元时，曲妥珠单抗联合化疗组具有经济性的概率低于45.6%。结论 曲妥珠单抗联合化疗方案治疗HER-2阳性晚期胃癌目前不具有经济性。

Objective To evaluate the cost-effectiveness of trastuzumab combined with chemotherapy versus chemotherapy for HER- 2-positive advanced gastric cancer from a health system perspective. Methods A partition survival model was constructed by referring to a phase III clinical trial data (ToGA study). The survival curve was extrapolated by fitting the best parameters to simulate the patient 's life, and the incremental cost-effectiveness ratio (ICER) was calculated by quality-adjusted life years (QALY). The robustness of the basic analysis results was verified by single factor sensitivity analysis and probability sensitivity analysis.Results Basic analysis showed that trastuzumab combined with chemotherapy increased 0.19 QALY compared with chemotherapy alone, and increased the cost by 65 352.42 yuan, which was greater than the willingness to pay threshold (WTP). Univariate sensitivity analysis showed that the three most sensitive factors to the model were progression-free survival (PFS) and progression (PD) and the cost of trastuzumab. Probabilistic sensitivity analysis showed that when WTP was less than 320 000.00 yuan, the probability of economy in trastuzumab combined with chemotherapy group was less than 45.6%. Conclusion Trastuzumab combined with chemotherapy in the treatment of HER-2 positive advanced gastric cancer is not economical.

R979.1