ABSTRACT
The time to a certain event is often an important outcome in medical or biological research. For exposure-response analysis, our primary interest is on the impact of exposure on the risk of an event, which can be quantified by using a model to fit time-to-event data. In this chapter we consider situations when the ER relationship is instant, i.e., the exposure level at a certain time only affects the risk at the same time. If the exposure has a cumulative effect, some special modeling techniques may be needed and will be described in a later chapter.
