陽明交通大學公衛所 Faculty Seminar

時間(Time)：113年9月30日(一) 12:10PM – 13:10PM

地點(Location)：醫學二館221教室

講者(Speaker)：戴以誠老師

講題(Title)：Two-Sample Treatment Effect Estimands under Nonproportional Hazards with Right-Censored Data

摘要(Abstract) : The addendum to ICH E9 provides guidance on enhancing the relevance and interpretability of clinical trial results through the use of estimands, directly addressing scientific questions. Currently, modern causal inference research is shaping the statistical inference framework from model-based methodologies to estimand-based inference procedures. With survival outcome data, the hazard ratio is traditionally considered as the gold standard to quantify the treatment effects. However, the advancements in immunotherapy for clinical oncology challenge the proportional hazards assumption, making the interpretation of hazard ratios questionable. While restricted mean survival time has emerged as an alternative, and other model-based estimation and testing methods have been proposed, there is still no consensus on the best approach to summarize the treatment effect under nonproportional hazards. In this talk, I will discuss the issues associated with nonproportional hazards in treatment effect quantification and introduce a new two-sample treatment effect estimand to assess the relative performance of two groups over time. This model-free estimand does not assume proportional hazards and is clinically interpretable. Our method includes a graphical tool to trace treatment progression and align relative changes in hazard functions, depicting the instantaneous effects of treatments. Additionally, I will briefly introduce my recent works on adapting the proposed method to mixture cure model and covariate-adjusted estimation.