varaktighetsdata
Varaktighetsdata (duration data) are measurements that record the length of time until an event occurs or until a process ends. They are common in fields such as medicine (time to relapse or death), reliability engineering (time to failure), and social sciences (duration of unemployment). Duration data can be complete, where the exact time-to-event is observed, or censored, where the event has not occurred by the end of the study or is known only to have occurred within an interval. Right-censoring is the most common, but left- and interval-censoring also occur.
Analyses of duration data are primarily conducted through survival analysis or duration models. Nonparametric methods, such
Key concepts include the survival function S(t) = P(T>t), the hazard function h(t), and the cumulative hazard
Software tools widely support duration-data analysis, including the R packages survival and flexsurv, Python lifelines, and