élettartamelemzések

élettartamelemzések refers to survival analysis, a broad area of statistical methods used to analyze the expected duration of time until one or more events happen. These events are often failures or death, but can also be other occurrences like the relapse of a disease, the termination of a contract, or the completion of a project. The primary goal of élettartamelemzések is to understand and quantify the factors that influence these time-to-event outcomes.

Key concepts within élettartamelemzések include the survival function, which describes the probability that an individual will survive beyond a certain time point, and the hazard function, which represents the instantaneous rate of an event occurring at a given time, given survival up to that point. Censoring is a crucial aspect, occurring when the event of interest has not yet happened for some individuals by the end of the observation period, or if they are lost to follow-up. Methods like the Kaplan-Meier estimator are used to estimate the survival function in the presence of censored data. Regression models, such as Cox proportional hazards regression, are employed to investigate the relationship between explanatory variables and the time to event. élettartamelemzések finds wide application in fields such as medicine, engineering, economics, and sociology to assess product reliability, patient prognoses, and economic durations.