WHEN ASKED TO CHOOSE, ARE WE CHOOSING WISELY? UTILIZATON OF AGE-ADJUSTED D-DIMERS IN LOW-PRETEST PROBABILITY OF PULMONARY EMBOLISM: A SINGLE-CENTER RETROSPECTIVE EXPERIENCE

Abstract

SESSION TITLE: Education, Research, and Quality Improvement Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The ABIM Foundation created the Choosing Wisely initiative to encourage physicians to be responsible agents of healthcare resources. The purpose of our study was to investigate the utilization of age-adjusted D-dimers in our academic community hospital via suggested clinical decision-making algorithms based on current evidence-based guidelines. Normal D-dimer in patients with a low to intermediate probability of PE by Well’s score has a very high negative predictive probability of PE obviating the need for computed tomography pulmonary angiograms (CTPA). However, CTPAs are unnecessarily performed in these patients. METHODS: We conducted a single-center retrospective analysis of non-critically ill hospitalized patients to the medical floors who had a D-dimer test performed between January 1st, 2019 through June 30th, 2019. 1601 D-dimer tests were performed during this period. We excluded 1308 patients discharged from the emergency room and/or admitted to the Intensive care unit. 293 patients were initially included. 134 patients who had ventilation-perfusion scans (V/Q) performed were excluded in accordance with exclusion criteria. In the final analysis, 159 patients were included. Well’s score was used to assess the initial pretest probability of PE at admission. Based on the Well’s score the patients were divided into two cohorts. The low pretest probability cohort with a score of <2 and intermediate cohort with a score between 2-6. In each of these cohorts, the age-adjusted D-dimers were used to further divide patients into D-dimer <500 ng/ml and D-dimer ≥500 ng/ml. Categorical outcomes were compared between study groups using Fisher’s exact test. RESULTS: In 159 patients, the mean age was 65.58 ± 14.91; 51.6% (82) were female. 113 had a low probability Well’s score <2 and 46 had an intermediate probability Well’s score of 2-6. The frequency of positive CTPA scans n=13 and negative CTPA scans n=146. An age-adjusted D-dimer <500 ng/ml in the low Well’s score cohort with positive CTPA 0 (0%) and negative CTPA 16 (100%). An age-adjusted D-dimer ≥500 ng/ml in the low Well’s score cohort with positive CTPA 5 (5.15%) and negative CTPA 92 (94.85%). In the intermediate Well’s score cohorts, an age-adjusted D-dimer <500 ng/ml and positive CTPA 1 (100%) and negative CTPA 0 (0%). In the intermediate Well’s score cohort, an age-adjusted D-dimer ≥500 ng/ml and positive CTPA 7(15.56%) and negative CTPA 38 (84.44%). The patient self-pay cost of a CTPA at our center is $242.74. The cumulative cost of positive CTPAs was $3,155.62 and negative CTPAs was $35,440.04. CONCLUSIONS: Despite robust society guidelines our center continues to utilize CTPA in patients with low to intermediate pretest probability. The estimated cost savings would have been 11.23%. CLINICAL IMPLICATIONS: The drawbacks of CTPAs include radiation exposure, risk of contrast-induced nephropathy, and increase in health care expenditure. DISCLOSURES: No relevant relationships by Padmastuti Akella, source=Web Response no disclosure submitted for Nitin Trivedi