Non-collapsibility and Built-in Selection Bias of Hazard Ratio in Randomized Controlled Trials
随机对照试验中风险比的不可折叠性与内生选择偏差
Background: The hazard ratio of the Cox proportional hazards model is widely used in randomized controlled trials to assess treatment effects. However, two properties of the hazard ratio including the non-collapsibility and built-in selection bias need to be further investigated. Methods: We conduct simulations to differentiate the non-collapsibility effect and built-in selection bias from the difference between the marginal and the conditional hazard ratio. Meanwhile, we…