The impact of cost displays on primary care physician laboratory test ordering

Physicians are under increased pressure to help control rising health care costs, though they lack information regarding cost implications of patient care decisions.

To evaluate the impact of real-time display of laboratory costs on primary care physician ordering of common laboratory tests in the outpatient setting.

Interrupted time series analysis with a parallel control group.

Two hundred and fifteen primary care physicians (153 intervention and 62 control) using a common electronic health record between April 2010 and November 2011. The setting was an alliance of five multispecialty group practices in Massachusetts.

The average Medicare reimbursement rate for 27 laboratory tests was displayed within an electronic health record at the time of ordering, including 21 lower cost tests (< $40.00) and six higher cost tests (> $40.00).

We compared the change-in-slope of the monthly laboratory ordering rate between intervention and control physicians for 12 months pre-intervention and 6 months post-intervention. We surveyed all intervention and control physicians at 6 months post-intervention to assess attitudes regarding costs and cost displays.

Among 27 laboratory tests, intervention physicians demonstrated a significant decrease in ordering rates compared to control physicians for five (19%) tests. This included a significant relative decrease in ordering rates for four of 21 (19%) lower cost laboratory tests and one of six (17%) higher cost laboratory tests. A majority (81%) of physicians reported that the intervention improved their knowledge of the relative costs of laboratory tests.

Real-time display of cost information in an electronic health record can lead to a modest reduction in ordering of laboratory tests, and is well received. Our study demonstrates that electronic health records can serve as a tool to promote cost transparency and reduce laboratory test use.