Does A Diagnostic Algorithm Reduce the Overuse of Chest CT Angiography in Suspected Pulmonary Embolism? : A Pre- and Post-Intervention Retrospective Study in a Critical Access Hospital

Abstract

Background: Pulmonary embolism (PE) is a common and potentially fatal disease. Although CTA is a gold standard for diagnosis, it carries risks for patients. We sought to minimize the overutilization of chest CTA by implementing a diagnostic algorithm in the hospital to evaluate the likelihood of PE and determine the need for imaging with CTA. Methods: A retrospective medical chart review was performed for all patients suspicious of PE at Redington-Fairview General Hospital 3 months before and after diagnostic algorithm implementation. Patients who underwent either D-dimer testing or chest CTA were included. Patients were excluded if d-dimer testing was performed for suspected deep vein thrombosis (DVT) alone or chest CTA was performed for other reasons. Patients were divided into 3 categories of probability according to their Wells scores. The algorithms from the American College of Physicians (ACP) were used to determine the next step of management. Results: A total of 414 patients were included in our study, 236 (57%) patients in 2017 and 178 (43%) patients in 2018. The mean age was 51 years (SD=19.17). A total of 168 CTAs were performed and found that 11 patients (15%) had PEs. There was a significant increase in the ordering of D-dimer levels after the diagnostic algorithm had been implemented (80.9% vs 89.3%, p=0.019), particularly in the low probability group. The use of D-dimer increased among patients in the low probability group who met PERC criteria (80.3% vs 97.17%, p=0.001). We observed an 11% reduction in the CTAs ordered in the post-intervention group compared to the pre-intervention group (45.3% vs 34.3%, p=0.023). Conclusion: Our study found that the implementation of a diagnostic algorithm for PE led to a significant reduction in the use of CTA.