Incremental Causal Effect for Time to Treatment Initialization

Music City Center 

We consider time to treatment initialization. This can commonly occur in preventive medicine, such as disease screening and vaccination; it can also occur with non-fatal health conditions such as HIV infection without the onset of AIDS; or in tech industry where items wait to be reviewed manually as abusive or not, etc. While traditional causal inference focused on `when to treat' and its effects, including their possible dependence on subject characteristics, we consider the incremental causal effect when the intensity of time to treatment initialization is intervened upon. We provide identification of the incremental causal effect without the commonly required positivity assumption, as well as an estimation framework including the efficient influence function. We illustrate our approach via simulation, and apply it to a real world data set.

positivity

stochastic intervention

inverse probability weighting

efficient influence function