Clinical decision support significantly reduces volume of CT pulmonary angiogram requests

A clinical decision support tool is showing the potential to significantly reduce the volume of CT pulmonary angiogram requests while also cutting healthcare spending on unnecessary imaging.

That’s according to a new analysis from Boston-based researchers, published in the Journal of the American College of Radiology [1]. Emergency department providers have reportedly overused CTPA for the diagnosis of pulmonary embolism, despite low yields. One 2020 study estimated that only about 1% to 5% of all such exams ordered are diagnostic of PE.

Rachel P. Rosovsky, MD, and colleagues developed and evaluated a clinical decision support tool to curb this concern across a 12-hospital community health system. They highlighted a nearly 15% relative decrease in CTPA utilization in the year following implementation, while yield from these exams remained unchanged.

“Although the impetus behind our CDS tool for suspected PE was the global IV contrast media shortage, using an evidence-based prediction tool to reduce the number of CTPAs has the potential to decrease potential harm and costs associated with unnecessary CT imaging, including kidney injury and allergic reactions from IV contrast, as well as radiation exposure,” Rosovsky, a hematologist and clinical investigator at Massachusetts General Hospital, and colleagues wrote in JACR.

Mass General Brigham—which operates nine emergency departments handling over 470,000 ED visits annually—designed the CDS tool over a two-week period. It implemented the system in June 2022 amid the imaging agent shortage at the time.  A multidisciplinary expert panel from the departments of emergency medicine, radiology and hematology, along with an EHR team, was tasked with creating the decision-support system. The research was funded in party by grants from the Gordon and Betty Moore Foundation and the Agency for Healthcare Research and Quality.

“Leveraging a multidisciplinary team to design the CDS tool and embedding it into a systemwide EHR enabled rapid implementation time,” the authors noted. “Enabled through a unified central clinical governance and access to a provider-led repository of vetted medical evidence, the CDS enabled clinicians to risk stratify their patients in real time and in one place.”

For the study, Rosovsky and colleagues compared data from the 12 months leading up to CDS implementation against the one year afterward (June 2022 to May 2023). Across nearly 932,000 visits to participating ED departments, providers performed about 28,000 CTPAs on 25,000 patients. Prior to implementing clinical decision support, Massachusetts providers performed 15,000 CTPAs in a single year across 455,000 visits (for a rate of 3.26%). After adding CDS, the rate dropped to 2.79% or about 13,000 exams across almost 477,000 visits. That amounts to a 14.51% relative decrease in CT pulmonary angiography utilization. CTPA yield remained unchanged at 9.25% before versus 8.92% after adding the support system.

Patients with COVID-19 diagnosis prior to CT had higher probably of acute pulmonary embolism, the authors noted.

“A major confounding factor in our study is the influence of COVID on [venous thrombosis] disease. Moreover, the proximity of the study to COVID may have impacted the prevalence of PE and thus, the rates of PE positivity in the post intervention period,” the authors cautioned. “Although our study demonstrated a decrease in utilization, due to numerous variables involved in cost analysis, this topic was not explored. However, this question can be addressed in future studies.”