Dear all, I am using the package mediation in order to perform a parametric mediation analysis on survival data. I have 8 variables: - Mediator - Treat - time (days) - death (event) - X1-X4 (confounding variables) I ran the following code to estimate the causal mediation effects. med.m = lm(Mediator ~ Treat + X1 + X2 + X3 + X4) med.y = survreg(Surv(time, death) ~ Treat + X1 + X2 + X3 + Mediator + X4) med.out <- mediate(med.m, med.y, treat = "Treat", mediator = "Mediator") summary(med.out) Here are the output provided by this script: Causal Mediation Analysis Quasi-Bayesian Confidence Intervals ? ? ? ? ? ? ? ? ? ? ? ? ? ?Estimate 95% CI Lower 95% CI Upper p-value ACME (control)? ? ? ? ? ?-3.68e+02? ? -1.27e+03? ? -3.34e+01? ? 0.01 ACME (treated)? ? ? ? ? ?-1.47e+02? ? -4.46e+02? ? -1.67e+01? ? 0.01 ADE (control)? ? ? ? ? ? -3.76e+03? ? -1.18e+04? ? -5.93e+02? ? 0.00 ADE (treated)? ? ? ? ? ? -3.54e+03? ? -1.14e+04? ? -5.53e+02? ? 0.00 Total Effect? ? ? ? ? ? ?-3.91e+03? ? -1.20e+04? ? -6.79e+02? ? 0.00 Prop. Mediated (control)? 9.56e-02? ? ?1.55e-02? ? ?2.36e-01? ? 0.01 Prop. Mediated (treated)? 3.82e-02? ? ?7.03e-03? ? ?1.49e-01? ? 0.01 ACME (average)? ? ? ? ? ?-2.57e+02? ? -8.36e+02? ? -2.46e+01? ? 0.01 ADE (average)? ? ? ? ? ? -3.65e+03? ? -1.16e+04? ? -5.78e+02? ? 0.00 Prop. Mediated (average)? 6.69e-02? ? ?1.17e-02? ? ?1.90e-01? ? 0.01 Sample Size Used: 713 Simulations: 1000 My problem is that I do not understand how to interpret the value of the estimate obtained for the ACME (control) parameter. I know that when the response variable (Y) is binary, this estimate can be interpreted as the increase in terms of probability of the event for control subjects. What is the good interpretation when the response variable (Y) in the model is a survival object ? Does it indicates here a decrease expressed in number of days (368) ? According to the Prop. Mediated (average) value (i.e last row of the table), can I conclude that about 6.69% of the total effect of Treat on Y is explained by the indirect effect of Mediator ? Thanks for your consideration, Best regards, Kendejan [[alternative HTML version deleted]]