Over-testing is a source of significant health care costs, both in terms of dollars spent and the false positives generated. Clinicians frequently test patients with elevated liver enzymes (a common problem) for Wilson disease (a rare disease) using a ceruloplasmin level.

We performed a prospective pre-post study between October 2013 and November 2014. We deployed a pop-up screen in our provider order entry system to present clinicians with the guidelines for and test characteristics of ceruloplasmin use. Outcomes included rate ratios for test utilization. Indications for inpatient orders were provided by ordering clinicians and reviewed.

Ceruloplasmin was ordered 448 and 219 times in the pre- and postintervention periods, respectively. Rate ratios for orders from gastroenterologists and general internists were 0.49; 95% confidence interval (CI), 0.40-0.59, and 0.31; 95% CI, 0.20-0.50, respectively (P <.0001, for both). Following the intervention, there was an 82% and 40% decrease in orders by internists in the outpatient and inpatient settings, respectively. Tests of confirmation (necessary for positive ceruloplasmins) were more common in the group tested following the intervention, risk ratio 1.80; 95% CI, 1.04-3.08; P = .02. Of the residual ceruloplasmin orders by inpatient internists after the intervention, 75% (18/24) were recommended by hepatology consultants.

The optimal intervention for the reduction of over-testing should include automated changes to the ordering system combined with efforts to change testing culture through education.