ObjectivesEthicists advise that life-sustaining treatment decisions should be made in keeping with patient preferences. Until recently, there has been little systematic study of the impact of patient preferences on the use of various life-sustaining treatments or the consequent cost of hospital care. This prospective study was designed to answer the following questions: a) Do patient treatment preferences about the use of life-sustaining treatment influence the treatments they receive? and b) Do patient treatment preferences influence the total cost of their hospitalization?DesignA prospective, cohort study.SettingA university teaching hospital.PatientsHospitalized patients, at least 50 yrs of age, with short life expectancy due to end-stage heart, lung, or liver disease, metastatic cancer, or lymphoma.InterventionsNone.Measurements and Main ResultsPatients were interviewed to determine their desire for life-sustaining treatment and other characteristics and then were followed for 6 months to determine life-sustaining treatment use and costs during hospitalization.Two hundred forty-four patients were interviewed. Fifty-eight percent of patients expressed a desire for life-sustaining treatments to prolong life for 1 wk. During 245 subsequent hospitalizations, there were 20 episodes of mechanical ventilation, 63 episodes of intensive care, and 66 cancer treatments given. Bivariate and multivariate analyses showed no significant association between patient desire to receive treatment to prolong life and either life-sustaining treatment use (p = .59) or hospital costs (p = .20).ConclusionIn a university teaching hospital setting, there is no systematic evidence that patient preferences determine life-sustaining treatment use or hospital costs.(Crit Care Med 1996; 24:1811-1817)