D-Dimer Use and Pulmonary Embolism Diagnosis in Emergency Units: Why Is There Such a Difference in Pulmonary Embolism Prevalence between the United States of America and Countries Outside USA?

PLoS One. 2017 Jan 13;12(1):e0169268. doi: 10.1371/journal.pone.0169268. eCollection 2017.


Objective: Although diagnostic guidelines are similar, there is a huge difference in pulmonary embolism (PE) prevalence between the United States of America (US) and countries outside the USA (OUS) in the emergency care setting. In this study, we prospectively analyze patients' characteristics and differences in clinical care that may influence PE prevalence in different countries.

Methods: An international multicenter prospective diagnostic study was conducted in a standard-of-care setting. Consecutive outpatients presenting to the emergency unit and suspected for PE were managed using the Wells score, STA-Liatest® D-Dimers and imaging.

Results: The prevalence of PE in the study was 7.9% in low and moderate risk patients. Among the 1060 patients with low or moderate pre-test probability (PTP), PE prevalence was four times higher in OUS (10.7%) than in the US (2.5%) (P < 0.0001). The mean number of imaging procedures performed for one new PE diagnosis was 3.3 in OUS vs 17 in the US (P < 0.001). Stopping investigation in the case of negative D-dimers (DD combined) with low/moderate PTP was more frequent in OUS (92.7%) than in the US (75.7%) (P < 0.01). Moreover, the use of imaging was much higher in the US (44.4% vs 19.2% in OUS) in the case of moderate PTP combined with negative DD.

Conclusion: Differences between US and OUS PE prevalence in emergency setting might be explained by differences in patients' characteristics and mostly in care patterns. US physicians performed computed tomographic pulmonary angiography more often than in Europe in cases of low/moderate PTP combined with negative DD.

Trial registration: ClinicalTrials.gov NCT01221805.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Angiography / trends*
  • Biomarkers / metabolism
  • Canada / epidemiology
  • Emergency Service, Hospital / statistics & numerical data*
  • Europe / epidemiology
  • Female
  • Fibrin Fibrinogen Degradation Products / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Outpatients
  • Prevalence
  • Prospective Studies
  • Pulmonary Embolism / diagnosis*
  • Pulmonary Embolism / epidemiology*
  • Pulmonary Embolism / metabolism
  • Tomography, X-Ray Computed / methods
  • United States / epidemiology
  • Young Adult


  • Biomarkers
  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D

Associated data

  • ClinicalTrials.gov/NCT01221805

Grant support

This work was supported by Diagnostica Stago. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.