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

BACKGROUND: Physicians are under increased pressure to help control rising health care costs, though they lack information regarding cost implications of patient care decisions. OBJECTIVE: To evaluate the impact of real-time display of laboratory costs on primary care physician ordering of common laboratory tests in the outpatient setting. DESIGN: Interrupted time series analysis with a parallel control group. PARTICIPANTS: 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. INTERVENTION: 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). MAIN MEASURES: 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. KEY RESULTS: 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. CONCLUSIONS: 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.