When providers follow CDS guidelines, the odds of an acute PE finding improve significantly

The influence of clinical decision support (CDS) systems in emergency departments (EDs) continues to grow, but what happens when physicians choose to override CDS recommendations? According to a recent study published in Radiology, the odds of an acute pulmonary embolism (PE) finding were much higher when providers followed CDS guidelines than when alerts were overridden.

Lead author Zihao Yan, BS, from the Center for Evidence-Based Imaging at Brigham and Women’s Hospital in Boston, and colleagues wrote that CDS can help improve workflow and improve guideline adherence, but physicians often override CDS recommendations without providing any sort of clinical justification.

“It is not known whether this exercise of clinical judgment in overriding CDS is warranted,” the authors wrote. “We sought to determine the frequency of, and yield after, provider overrides of evidence-based CDS for CT pulmonary angiography in the ED.”

Yan et al. analyzed data from Jan. 1, 2011, to August 31, 2013, at a trauma center ED that sees approximately 60,000 patients per year. The CDS system being used would calculate a Wells score for each patient ranging from 0 to 12.5. For patients with a score greater than 4, the system recommended CT pulmonary angiography; for patients with a score equal to or less than 4, the system recommended D-dimer testing to help rule out PE.

Overall, the authors found that providers did not adhere to CDS recommendations during more than 19 percent of all CT pulmonary angiographic exams. With differences in risk factors taken into account, the odds of an acute PE finding were more than 51 percent lower when providers overrode alerts than when they followed CDS guidelines.

“Our findings suggest that stronger interventions may be needed to further reduce the nearly 20 percent of CT pulmonary angiography requests that override education-only CDS alerts, primarily by ignoring D-dimer testing in patients unlikely to have PE,” the authors wrote. “Further studies are needed to determine what subset of this patient population would benefit from D-dimer testing, which, if providing normal results, would obviate CT pulmonary angiography. Education-only CDS interventions, even if based on validated decision rules, are unlikely to optimize evidence-based decision making if providers can simply ignore CDS alerts and proceed with imaging.”

Yan and colleagues noted that their study did have limitations. For example, results came from a single institution, so the results may not match up with care provided at other institutions throughout the U.S. In addition, some of the patients underwent numerous CT pulmonary angiographic studies, and each repeat exam was considered an independent study.

“Considering the small proportion of repeated studies and the long mean interval between them, we do not believe the inclusion of repeat studies changed our conclusion,” the authors wrote.