Suboptimal implementation of diagnostic algorithms and overuse of computed tomography-pulmonary angiography in patients with suspected pulmonary embolism

BACKGROUND Majority of our computed tomography-pulmonary angiography (CTPA) scans report negative findings. We hypothesized that suboptimal reliance on diagnostic algorithms contributes to apparent overuse of this test. METHODS A retrospective review was performed on 2031 CTPA cases in a large hospital system. Investigators retrospectively calculated pretest probability (PTP). Use of CTPA was considered as inappropriate when it was ordered for patients with low PTP without checking D-dimer (DD) or following negative DD. RESULTS Among the 2031 cases, pulmonary embolism (PE) was found in 7.4% (151 cases). About 1784 patients (88%) were considered "PE unlikely" based on Wells score. Out of those patients, 1084 cases (61%) did not have DD test prior to CTPA. In addition, 78 patients with negative DD underwent unnecessary CTPA; none of them had PE. CONCLUSIONS The suboptimal implementation of PTP assessment tools can result in the overuse of CTPA, contributing to ineffective utilization of hospital resources, increased cost, and potential harm to patients.