RESUMEN
Background: Hospitals must have management tools that allow them to fulfil all their requirements with the allocated resources. Aim: To evaluate the number of bed-days according to the discharge diagnosis in a High Complexity Hospital in Chile. Material and Methods: An activity Based Cost (ABC) calculation was used. The stages were gathering of procedures, identification of the resources used, analysis of discharge diagnosis, definition of cost objects, resource cost drivers, cost of procedures, procedures cost drivers and cost of the cost objects that corresponds to bed-day by each medical specialty. Costs were calculated for Medical-Surgical and Intermediate Care units. Results: There were significant differences in costs according to medical specialty when comparing the costs obtained using the Management information system (WinSig) and ABC. Respiratory, Renal and Circulatory-Cardiovascular specialties accounted for the most expensive bed-days. Conclusions: This study identified bed-day costs and provides disaggregated information about the causes of cost differences between medical specialties.