This study analyzed the effect information sharing through physician profiling would have on emergency physician behavior.

It is a before-and-after audit of laboratory use in a community hospital.

A 9-month control period was followed by a 15-month period in which the physicians'laboratory use was presented and discussed at monthly meetings.

The laboratory use decreased 17.8%, from a mean of 2.36 studies per patient during the control period to 1.94 during the final quarter of the study.

The actual laboratory costs per month decreased 17.7%, from a mean of $32,415 per month to $26,687 per month.

There was only one possible adverse outcome out of 34,320 patients seen.

There were no adverse changes in other quality improvement indicators.

Information sharing can result in a decrease in the number and cost of laboratories studies ordered by emergency physicians without an adverse change in routine quality improvement indicators.