ObjectiveTo cost adult intensive care by determining inputs to production, resource consumption per patient, and total cost per intensive care unit (ICU) stay.DesignProspective cost-accounting analysis of each patient stay in the ICU, over a 1-yr period.SettingAn 11-bed, medical/surgical adult ICU, in a 932-bed urban teaching hospital.PatientsAll patients' admissions to an adult ICU over a 1-yr period, excluding those patients admitted solely for repeat hemodialysis.InterventionsNone.Measurement and Main ResultsDemographic information was collected, including age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II score, primary reason for ICU admission, operative (elective and emergency) and nonoperative status, ICU length of stay, and ICU outcome.Direct patient care costs were accounted to individual patients whose care generated those costs, and indirect patient care costs were averaged over all patients in the ICU on a daily basis. Costs were collected for human (nursing, medical, professional, and support staff) and capital (laboratory, diagnostic imaging, supplies, drugs, and equipment) resources.Cost information was available on 690 patients (43% female, 57% male). Cost/day/patient was $1,508 plus minus 475 (1992 Canadian dollars) and the average cost per ICU stay was $7,520 plus minus 11,606. Median cost/stay for all patients was $2,600. Cost per ICU stay was less than $5,000 in 68% of patients, with an ICU survival rate of 85%. High cost was not a marker for poor survival. There was no relationship between age and cost categories. Across most diagnoses, cost/day/patient was remarkably constant, approximating $1,500/day/patient at existing labor rates.ConclusionsIn order to develop strategies aimed at cost containment, it is first necessary to undertake a thorough examination of cost drivers. This detailed cost-accounting study determined inputs to production, resources consumed by individual patients, and costs incurred during ICU stay.(Crit Care Med 1996; 24:1168-1172)