title: 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?
abstract: 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.
  
  
  CONCLUSIONS
  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.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01221805.
authors.affiliation: Department of Vascular Medicine, Grenoble-Alpes University Hospital, Université Grenoble Alpes CNRS / TIMC-IMAG UMR 5525 / Themas, Grenoble, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Pernod
authors.affiliation: Department of Emergency Medicine, Ohio State University, Columbus (Ohio); United States of America.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Caterino
authors.affiliation: Department of Emergency Medicine, Grenoble-Alpes University Hospital, Grenoble, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Maignan
authors.affiliation: Department of Emergency Medicine, University Hospital Dijon, Dijon, France.
authors.forename: Cindy
authors.initials: C
authors.lastname: Tissier
authors.affiliation: Department of Hematology, Hopital Maisonneuve-Rosemont, University of Montreal, Montreal, Canada.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Kassis
authors.affiliation: Pathology and Laboratory Medicine, Medical University South Carolina, Charleston, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Lazarchick
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000639:trends*; D015415:Biomarkers / Q000378:metabolism; D002170:Canada / Q000453:epidemiology; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005060:Europe / Q000453:epidemiology; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D015995:Prevalence; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000453:epidemiology* / Q000378:metabolism; D014057:Tomography, X-Ray Computed / Q000379:methods; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D