Laboratory costs in the context of disease.

BACKGROUND To determine the contribution of laboratory costs to the overall costs of managing hospital patients with different diseases, we studied the costs of laboratory testing overall and in relation to the other costs incurred during hospitalization. METHODS We used a database developed by the University HealthSystems Consortium containing >1 million patients in 60 University Hospitals with diseases included in 486 diagnosis-related groups (DRGs). Laboratory costs included in the database comprised those associated with testing in the clinical laboratory together with those incurred in point-of-care testing and anatomic pathology but not those involving blood products and their transfusion. RESULTS The mean laboratory costs to manage surgical patients were greater than those to manage medical patients in 19 of the 25 major diagnostic categories. The median laboratory costs for patients with liver transplants exceeded $8000, and the laboratory costs to support other organ transplants were among the highest. The highest proportion of total costs attributable to the laboratory was 18.3% for acute leukemia and kidney and urinary tract signs and symptoms, both in children. Laboratory costs were <1.0% of the total costs for only 15 DRGs. The highest median daily laboratory cost, $416, was attributable to liver transplant patients. Several conditions had median laboratory costs less than $30 per day, in spite of lengths of stay that exceeded 10 days in some cases. CONCLUSIONS Although laboratory costs generally average 6% of the total costs for surgical conditions and 9% of the total costs for medical conditions, there is considerable variability. In general, laboratory costs were relatively poorly correlated with total costs. However, observation of high daily laboratory costs for many DRGs suggests that reducing length of stay would reduce both laboratory and total costs.