Explaining cost variations in DRGs 'Acute Myocardial Infarction' by severity of illness.

The empirical relationship is analyzed between the severity of illness and costs of medical care for 464 patients classified into DRGs 121-123, Acute Myocardial Infarction (AMI), in the University Hospital, Maastricht. Severity of cardiac and cardiovascular disorders characteristic of acute myocardial infarction is defined and operationalized in a sense that closely resembles the clinical practice of cardiologists. The effect of the severity of illness on DRG cost variations is studied separately for the costs of acute care (such as thrombolytic therapy, cardiac catheterization and percutaneous transluminal coronary angioplasty (PTCA)), length of hospital stay, costs of intensive nursing care at the coronary care unit (CCU) and the costs of ECGs, laboratory tests, echocardiography, exercise tests and drugs. For AMI patients, severity of illness measured by specific clinical criteria is found to give better predictions (higher R2) for costs of medical care than the DRG classification.