Model-based estimation of measures of association for time-to-event outcomes

Table 2 Event times generated according to a Cox-exponential model with a confounder X and an exposure status Z with time-dependent effect

The effect of Z is multiplied by log(t). CGPM was adopted using the Cox proportional hazard regression model with the time dependent effect of Z specified in two ways: (1) with an interaction between Z and log(t), corresponding to the generating model; (2) with and interaction between Z and a restricted cubic spline of time (rcs(t)). PV model was adopted with identity link. Pseudo times were fixed at quantiles 5%, 25%, 50%, 75%, 95% of the failure time distribution. The Z covariate was inserted with an interaction with the baseline risk function modelled with a restricted cubic spline with 3 knots, giving an estimated risk difference varying through follow-up time, RD(t).

ISSN: 1471-2288