It is known that the number of Chronic Critical İllnes, an iatrogenic condition, increases all over the world. The prevalence of Chronic Critical Illness in Turkey is unknown. The investigators aimed to evaluate the etiology, comorbid conditions, demographic data, prevalence, mortality and costs of these patient in intensive care units in Turkey. In this multi-centered study, The investigators will retrospectively review the last 1 year of patients receiving treatment at the Adult Intensive Care Unit.