Evaluation of utilization of laboratory tests in a hospital emergency room.

Visits to a metropolitan teaching hospital emergency room were evaluated for laboratory test utilizaion and quality of care of chart review. Of 630 tests, 197 (32 per cent), clustered in 44 out of 476 (9 per cent) patient visits, were considered unnecessary. The number of tests per visit showed a strong negative correlation with the necessity of tests and with the quality of care. Results suggest the usefulness of identifying a subgroup of patients with excessive tests and implementing measures to alter testing behavior for this subgroup.