Beijing International Center for Mathematical Research, Peking University, 100871 Beijing, China.
Department of Biostatistics, School of Public Health, 48109 Ann Arbor, Michigan, USA.
Biometrics. 2024 Mar 27;80(2). doi: 10.1093/biomtc/ujae032.
Semicompeting risks refer to the phenomenon that the terminal event (such as death) can censor the nonterminal event (such as disease progression) but not vice versa. The treatment effect on the terminal event can be delivered either directly following the treatment or indirectly through the nonterminal event. We consider 2 strategies to decompose the total effect into a direct effect and an indirect effect under the framework of mediation analysis in completely randomized experiments by adjusting the prevalence and hazard of nonterminal events, respectively. They require slightly different assumptions on cross-world quantities to achieve identifiability. We establish asymptotic properties for the estimated counterfactual cumulative incidences and decomposed treatment effects. We illustrate the subtle difference between these 2 decompositions through simulation studies and two real-data applications in the Supplementary Materials.
半竞争风险是指终端事件（如死亡）可以删失非终端事件（如疾病进展），但反之则不然。治疗对终端事件的影响既可以直接在治疗后产生，也可以通过非终端事件间接产生。我们考虑了两种策略，即在完全随机试验的中介分析框架下，通过调整非终端事件的流行率和危害度，将总效应分解为直接效应和间接效应。它们在实现可识别性方面需要略微不同的跨世界量假设。我们建立了估计的反事实累积发生率和分解治疗效果的渐近性质。我们通过模拟研究和补充材料中的两个实际数据应用说明了这两种分解之间的细微差别。
