In their paper, Liu et al. (2020) pointed out illogical discrepancies between subgroup and overall causal effects for some efficacy measures, in particular the odds and hazard ratios. As the authors show, the culprit is subgroups having prognostic effects within treatment arms. In response to their provocative findings, we found that the odds and hazard ratios are logic respecting when the subgroups are purely predictive, that is, the distribution of the potential outcome for the control treatment is homogeneous across subgroups. We also found that when we redefined the odds and hazards ratio causal estimands in terms of the joint distribution of the potential outcomes, the discrepancies are resolved under specific models in which the potential outcomes are conditionally independent. In response to other discussion points in the paper, we also provide remarks on association versus causation, confounding, statistical computing software, and dichotomania.

中文翻译：

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Yi Liu、Bushi Wang、Miao Yang、Jianan Hui、Heng Xu、Siyoen Kil 和 Jason C. Hsu 对“随机对照试验中二元和事件发生时间结果的正确和逻辑因果推断”的讨论

在他们的论文中，刘等人。(2020) 指出，对于某些疗效指标，特别是优势和风险比，亚组和整体因果效应之间存在不合逻辑的差异。正如作者所展示的，罪魁祸首是在治疗组中具有预后影响的亚组。作为对他们挑衅性发现的回应，我们发现，当亚组是纯预测性的时，优势和风险比是符合逻辑的，也就是说，对照治疗的潜在结果在亚组之间的分布是均匀的。我们还发现，当我们根据潜在结果的联合分布重新定义优势和风险比因果估计时，差异在潜在结果有条件独立的特定模型下得到解决。针对论文中的其他讨论点，