Physicians largely ignore CDS implemented to reduce unnecessary imaging

The authors of a new study in Academic Radiology developed a clinical decision support (CDS) algorithm to help physicians reduce overutilized imaging examinations in the emergency department (ED). The physicians, however, consistently disregarded its recommendations, reducing its impact.

The authors, wanting to focus on a commonly overutilized examination, surveyed more than 200 emergency providers and determined CT angiography (CTA) to assess for pulmonary embolism (PE) was the perfect candidate.

“Given the high level of agreement that CTA PE studies are at least moderately overutilized and the availability of widely accepted clinical algorithms to assess for PE, we chose CTA PE studies for this CDS pilot,” wrote Alexander Goehler MD, PhD, of the department of radiology at Brigham and Women’s Hospital in Boston, and colleagues. “This choice was made with the intention to raise awareness of CDS among our hospital staff and to engage local champions to ultimately prepare our institution for the larger roll-out of a mandatory CDS in 2018. We also found that the availability of literature on the use of CDS for PE studies would provide a benchmark.”

The team developed the CDS algorithm using feedback from ED physicians, ED radiologists and a pulmonologist. Once the CDS determined it wanted to recommend an alternative option to a physician ordering a CTA PE study, the physician was allowed to ignore that recommendation, but was asked to explain why. The pilot study lasted from April 1 to Oct. 31, 2015, at the ED of a 1,500-bed tertiary healthcare center.

Overall, 872 CTA PE studies were ordered in the healthcare center’s ED. For 55 percent of those orders, the CDS recommended the order be changed. However, just 1.3 percent of those studies were canceled. Another 2.7 percent were changed to a D-dimer blood test, an alternative to the CTA. Four D-dimer studies were positive, three of them lead to a follow-up CTA PE, and none of those CTA PAs were positive.

A total of 853 CTA PE studies were ultimately conducted in the healthcare center’s ED during the pilot study period, and just 8.2 percent were positive for a PE.

The authors noted that they worked closely with the physicians before the study began and even formed a “rapid response team” to address any concerns. However, physicians still largely ignored the system’s recommendations.

“Despite these efforts, studies that were identified as inappropriate were only changed in 4 percent of cases,” Goehler and colleagues wrote.

Why was adherence so low? The authors suggested that it may have been because trainees and mid-level providers work under the supervision of an attending physician.

“Since the case has been reviewed with the attending, and trainees or midlevel providers are instructed to order the test, it is less likely to change at this point,” the authors wrote. “There are likely also instances in which the study is requested even though the ordering provider expects a negative result but pursued in order to facilitate another aspect of the encounter. For instance, this may be done to expedite discharge when beds are scarce or to assess multiple potential differential diagnoses with a single imaging study, as may be the case in a patient with hypoxia and a known lung neoplasm or metastasis.”

The team also noted that this low adherence is not exactly new for researchers studying CDS.