In the previous chapters, we focused on dependent variables that were numerical, binary, categorical or counts. For these dependent variables, the timing of the occurrence of the outcome (event) was not a concern. For instance, if outcome of interest is the incidence of diabetes among participants, the diagnosis of diabetes is considered as an event. If a participant is diagnosed with diabetes, we say that an event has occurred; if a participant is not diagnosed, we consider that the event has not occurred. This kind of outcomes can be found in several study designs such as prospective or retrospective cohort studies, longitudinal studies, clinical trial, and experimental studies where time to entry the study and the outcome status is assessed.