Correcting for bias due to mismeasured exposure in mediation analysis with a survival outcome
研究了暴露测量误差如何影响Cox回归模型下生存结局的中介效应估计，推导了偏倚公式并开发了多种校准方法，应用于健康专业人员随访研究以评估体重指数在体力活动与心血管疾病风险之间的中介作用。
We investigate the impact of exposure measurement error on assessing mediation with a survival outcome modelled by Cox regression. We first derive the bias formulas of natural indirect and direct effects with a rare outcome and no exposure-mediator interaction. We then develop several calibration approaches to correct for the measurement error-induced bias, and generalize our methods to accommodate a common outcome and an exposure-mediator interaction. We apply the proposed methods to analyse the Health Professionals Follow-up Study (1986-2016) and evaluate the extent to which reduced body mass index mediates the protective effect of physical activity on risk of cardiovascular diseases.