ABSTRACT
Survival data is a term used for describing data that measure the time to a certain event. In survival analysis, the event may be death, occurrence of disease (or complication), time to an epileptic seizure, time it takes for a patient to respond to a therapy, or time from response until disease relapse (i.e., disease returns). In demography, the event can be entering marriage. The event is a transition from one state to another. Death is a transition from state alive to the state dead. Occurrence of disease is a transition from the state of being healthy to a state of presence of disease. Marriage is the transition of being unmarried to being married. For epileptic seizure, an event is a transition from the seizure-free state to the state of active seizure.
