Variation in Positivity Rates of Computed Tomography Pulmonary Angiograms for the Evaluation of Acute Pulmonary Embolism Among Emergency Department Physicians

Computed tomography pulmonary angiography (CTPA) is an imaging study for which there is substantial evidence for its overuse in the evaluation of acute pulmonary embolism (PE). Prior literature has reported low positive PE rates, but the variability in positive rates among the ordering physicians has not been as well studied. The purpose of this study was to evaluate variation in ordering and positive rates among physicians in an emergency department (ED) within an integrated health care system. This study was based in a single ED that is part of a geographically isolated integrated health care system. We reviewed the patient records for all patients who underwent a CTPA for the evaluation for acute PE in the ED between January 1, 2018, and December 31, 2019. For each CTPA examination, we recorded the ordering ED physician, serum d-dimer value (mcg/mL), if any, and the results of the CTPA. Review of CTPAs over the 2-year period revealed 1380 CTPAs ordered by 23 ED physicians with a range of 25–141 studies per physician (mean of 60 + 31 CTPAs). The overall positive rate for PE was 6.9%. Individual ED physician positivity rates showed wide variability ranging from 0% to 18.4% (mean positive rate 7.6 + 4.4%). The results of this study confirm the need for greater adherence to existing guidelines using clinical decision rules and d-dimer testing when appropriate among all ED physicians but especially those who order a greater number of studies and have low rates for positive PE.