Welcome to the eighteenth episode of AEM Early Access, a FOAMed podcast collaboration between the Academic Emergency Medicine Journal and Brown Emergency Medicine. Each month, we'll give you digital open access to an recent AEM Article or Article in Press, with an author interview podcast and suggested supportive educational materials for EM learners.

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DISCUSSING (OPEN ACCESS THROUGH SEPTEMBER 30, 2018; CLICK ON TITLE TO ACCESS):

Multicenter Evaluation of the YEARS Criteria in Emergency Department Patients Evaluated for Pulmonary Embolism. Christopher Kabrhel MD,MPH  Astrid Van Hylckama Vlieg PhD  Alona Muzikanski MS Adam Singer MD  Gregory J. Fermann MD  Samuel Francis MD  Alex Lim kakeng MD Ann Marie Chang MD  Nicholas Giordano MA  Blair Parry BA.

LISTEN NOW: INTERVIEW WITH LEAD AUTHOR DR. KABRHEL:

ABSTRACT:

Background
It may be possible to safely rule out pulmonary embolism (PE) in patients with low pre‐test probability (PTP) using a higher than standard D‐dimer threshold. The YEARS criteria, which includes three questions from the Wells PE Score to identify low PTP patients and a variable D‐dimer threshold, was recently shown to decrease the need for imaging to rule out PE by 14% in a multicenter study in the Netherlands. However, the YEARS approach has not been studied in the United States.

Methods
Prospective, observational study of consecutive adult patients evaluated for PE in 17 U.S. emergency departments. Prior to diagnostic testing, we collected the YEARS criteria: “Does the patient have clinical signs or symptoms of DVT?”, “Does the patient have hemoptysis?”, “Are alternative diagnoses less likely than PE?” with YEARS (+) being any “yes” response. A negative D‐dimer was <1000 mg/dL for YEARS (‐) patients, and <500 mg/dL for YEARS (+) patients. We calculated test characteristics and used Fisher's exact test to compare proportions of patients who would have been referred for imaging and patients who would have had PE “missed.”.

Results
Of 1789 patients, 84 (4%) had PE, 1134 (63%) were female, 1038 (58%) were White and mean age was 48 years. Using the standard D‐dimer threshold, 940 (53%) would not have had imaging, with 2 (0.2%, 95% CI: 0.02%, 0.60% “missed” PE. Using YEARS adjustment, 1204 (67%, 95% CI: 65%, 69%) would not have been referred for imaging, with 6 (0.5%, 95% CI: 0.18%, 1.1%) “missed” PE, and using “alternative diagnoses less likely than PE” adjustment, 1237 (69%, 95% CI: 67%, 71%) would not have had imaging with 6 (0.49%, 95% CI: 0.18%, 1.05%) “missed” PE. Sensitivity was 97.6% (95% CI: 91.7%‐99.7%) for the standard threshold, and 92.9% (95% CI: 85%‐97%) for both adjusted thresholds. NPV was nearly 100% for all approaches.

Conclusions
D‐dimer adjustment based on pre‐test probability may result in a reduced need for imaging to evaluate possible PE, with some additional “missed” PE but no decrease in NPV.