Supplementary Material for: Cost-Effectiveness of <b><i>IL28Β</i></b> Genotype-Guided Protease Inhibitor Triple Therapy versus Standard of Care Treatment in Patients with Hepatitis C Genotypes 2 or 3 Infection

<b><i>Background/Aims:</i></b> Triple therapy [adding protease inhibitors to standard of care (SOC)] dramatically increases treatment response in selected patients with hepatitis C virus (HCV). Interleukin 28B <i>(IL28Β)</i> genotyping helps predict responsiveness in these patients; however, the economic implications of <i>IL28Β</i> genotyping in HCV genotype 2 or 3 infected patients are unknown. Short- and long-term costs and outcomes of SOC therapy were calculated and used to determine the cost-effectiveness thresholds for using triple therapy in HCV genotype 2 or 3 infected patients. <b><i>Methods:</i></b> Costs and outcomes were calculated by conducting cohort simulations on decision trees modeling SOC and triple therapy. Quality-adjusted life expectancies and long-term costs were predicted through Markov modeling. <b><i>Results:</i></b> For triple therapy to be cost-effective, sustained virologic response (SVR) rates must improve (depending on age) by 7.91-11.11 and 9.06-12.8% for HCV genotype 2 and 3 cohorts, respectively. When triple therapy is guided by 2 <i>IL28Β</i> variants, a 2.63-3.72% improvement in SVR is needed for cost-effectiveness, and when guided by only one variant, a 1.4-8.91% improvement is needed. <b><i>Conclusions:</i></b> Markov modeling revealed that modest increases in SVR rates from <i>IL28Β</i>-guided triple therapy can lead to both lower costs and better health outcomes than SOC therapy in the long run.<b><i>背景与目的:</i></b> 三联疗法（在标准治疗方案（standard of care, SOC）基础上加用蛋白酶抑制剂）可显著提升特定丙型肝炎病毒（hepatitis C virus, HCV）感染患者的治疗应答率。白细胞介素28B（Interleukin 28B, IL28Β）基因分型有助于预测此类患者的治疗应答情况，但针对HCV基因型2或3型感染患者开展IL28Β基因分型的经济学意义尚不明确。本研究通过计算标准治疗方案的短期与长期成本及结局，旨在明确针对HCV基因型2或3型感染患者采用三联疗法的成本效益阈值。 <b><i>方法:</i></b> 通过构建标准治疗方案与三联疗法的决策树模型开展队列模拟，以此计算治疗成本与结局。同时借助马尔可夫模型（Markov modeling）预测患者的质量调整生命年与长期治疗成本。 <b><i>结果:</i></b> 若要使三联疗法具备成本效益，针对HCV基因型2型与3型队列患者，其持续病毒学应答（sustained virologic response, SVR）率需分别提升7.91%~11.11%与9.06%~12.8%。当采用2种IL28Β变异体指导三联疗法时，需使SVR率提升2.63%~3.72%方可实现成本效益；若仅采用1种IL28Β变异体指导治疗，则需提升1.4%~8.91%的SVR率。 <b><i>结论:</i></b> 马尔可夫模型分析结果显示，相较于标准治疗方案，经IL28Β基因分型指导的三联疗法若能适度提升SVR率，长期而言可同时降低治疗成本并改善健康结局。