Medical procedures in a hospital will contain a cost component. These cost components is present not only for the medical procedure directly, but also from a variety of other activities performed before and after medical procedures are done. Calculation of the cost of medical procedures should be done when dealing with two equally effective medical procedures. The cost elements of a complex medical procedure that involves the use of an operating room include: Cost of diagnosis, emergency room, laboratory, operating room, pharmaceuticals, radiology, respiratory support, rooms, supplies, therapy, other costs. After all costs for any medical procedure are known, the difference in total hospital costs for medical procedures compared is calculated statistically using analysis of covariance (ANCOVA). In the ANCOVA procedure, the cost calculation from each element above needs to be adjusted to the patient characteristics. Patient characteristics generally taken into account in the costs adjustment include: Patient age, Sex of the patient, Admission status, and Severity of illness..