Determinants of hospital charges and costs in acute myocardial infarction: A report from the Myocardial Infarction Cost Study (MICS) Group

This study was designed to investigate hospital costs and charges, and their determinants, in a broad range of patients with acute myocardial infarction at several US medical centers. Data were collected from 16 acute care hospitals. Clinical data were retrieved from the hospital record, and hospital charges from the UB-92. Costs were estimated by multiplying the charge by the overall hospital Medicare cost-to-charge ratio. Determinants of cost were determined by multiple regression. The mean charge and mean cost for the 302 patients included in the study (mean age, 63 ± 13 years; 65% male; thrombolysis in 39%) were $29,517 ± $25,027 and $16,933 ± $14,436, respectively. The only clinical variable available on admission correlating with charge and cost was Killip class. By considering all significant variables, 81% of the variation in hospital costs could be determined. The need for coronary artery bypass surgery had the greatest effect on costs ($31,400 ± $14,300 with surgery, versus $15,100 ± $13,500 without), but length of stay was the most powerful correlate of cost ($9,300 ± $6,100 for lengths of stay of less than 6 days, compared with $32,300 ± $22,800 for stays of 13 or more days). Treatment of acute myocardial infarction may be more expensive than is commonly realized. Although costs varied considerably across institutions, they could not be predicted easily on admission, as most of the variation resulted from the need for coronary surgery or from variations in lengths of stay. Consequently, the cost of treatment for acute myocardial infarction might be reduced by careful selection of patients for revascularization procedures.