The expense of testing in a teaching hospital: the predominant role of high-cost tests.

We analyzed all 32,206 tests ordered in a random sample of 1,000 patients admitted to a teaching hospital. The analysis examined costs instead of charges, included professional costs in addition to hospital costs, and considered the effect of combining tests that are ordered as a panel (e.g., cardiac enzymes) or as part of a procedure (e.g., bronchoscopy). High-cost tests (costing more than $100) accounted for only 4 percent of the total number of tests ordered, but for nearly 50 percent of total test costs. The pattern varied by clinical service: high-cost tests accounted for 31, 47, and 51 percents of total test costs on the obstetrics, medicine, and surgery services, respectively. It would seem to be efficient to concentrate on the use of high-cost tests in attempting to foster cost-effective use of diagnostic technologies.