Identification of risk factors for increased cost, charges, and length of stay for cardiac patients

Background. In this study we explored different risk model options to provi de clinicians with predictions for resource utilization. The hypotheses wer e that predictors of mortality are not predictive of resource consumption, and that there is a correlation between cost estimates derived using a cost -to-charge ratio or a product-line costing approach. Methods. From March 1992 to June 1995, 2,481 University of Colorado Hospita l patients admitted for ischemic heart disease were classified by diagnosis -related group code as having undergone or experienced coronary bypass proc edures (CBP), percutaneous cardiovascular procedures (PCVP), acute myocardi al infarction (AMI), and other cardiac-related discharges (Other). For each diagnosis-related group, Cox proportional hazards models were developed to determine predictors of cost, charges, and length of stay. Results. The diagnosis groups differed in the clinical factors that predict ed resource use. As the two costing methods were highly correlated either a pproach may be used to assess relative resource consumption provided costs are reconciled to audited financial statements. Conclusions. To develop valid prediction models for costs of care, the clin ical risk factors that are traditionally used to predict risk-adjusted mort ality may need to be expanded. (Ann Thorac Surg 2000;70:702-10) (C) 2000 by The Society of Thoracic Surgeons.