User:Input trust/sandbox

= Occluding event = An occluding event is relevant in time-to-event analyses and is defined as any loss to further follow-up and/or removal of further collected data from analysis without having experienced the event of interest. Occlusion occurs at the point the patient leaves the risk set.

Occlusion represents generally the act preventing observation of or resulting in discarding data. Censoring is a kind of occlusion, including both censoring as the result of the pre-specified end of the study, and censoring which results in discarding data at analysis time that was actually observed and collected in the study. But occlusion need not be handled only through censoring. It could be handled through, for example, a competing risk event, composition, or a (causal) hypothetical method, all of which also result in the analysis not looking further than the occluding event.

Terminality is an objective property of an event which renders further observation physically impossible. If an event is terminal, it is impossible to devise a study that can look beyond it. Indeed there is no meaningful clinical question regarding the treatment effect that manifests after a terminal event. Occlusion, however, is context-specific. It can arise from a decision not to observe further, or even a decision to discard data already observed.