title: The emergency department utility of Simplify D-dimer to exclude pulmonary embolism in patients with pleuritic chest pain.
abstract: OBJECTIVE
  Pleuritic chest pain is a common presenting complaint in the emergency department (ED) and a symptom of pulmonary embolism. Patients with pleuritic chest pain would benefit from a simple and rapid way of screening for pulmonary embolism. The aim of this study is to assess the utility of Simplify D-dimer as a rule-out tool for pulmonary embolism in ED patients with pleuritic chest pain.
  
  
  METHODS
  This was a prospective diagnostic study in a large city-center ED. Four hundred twenty-five patients with pleuritic chest pain were prospectively recruited between February 2002 and June 2003. Simplify D-dimer testing was performed on each patient in the ED. All patients followed an independent reference standard diagnostic algorithm for pulmonary embolism. Each patient was followed up clinically for 3 months.
  
  
  RESULTS
  The calculated sensitivity of Simplify D-dimer for pulmonary embolism was 81.8% (95% confidence interval [CI] 61.4% to 92.7%), and specificity was 74.2% (95% CI 69.6% to 78.4%). The negative predictive value was 98.6% (95% CI 96.6% to 99.6%), positive predictive value 15.0% (95% CI 9.1% to 22.7%), negative likelihood ratio 0.25 (95% CI 0.10 to 0.52) and positive likelihood ratio 3.17 (95% CI 2.30 to 3.97). The study cohort pretest probability was 5.3%. A negative Simplify result reduced the posttest probability to 1.3% (95% CI 0.5% to 3.4%).
  
  
  CONCLUSIONS
  The Simplify D-dimer is not sufficiently sensitive to exclude the diagnosis of pulmonary embolism in all patients presenting to the ED with pleuritic chest pain.
authors.affiliation: Emergency Department, Manchester Royal Infirmary, Manchester, United Kingdom. kerstinhogg@hotmail.com
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hogg
authors.forename: Deborah
authors.initials: D
authors.lastname: Dawson
authors.forename: Kevin
authors.initials: K
authors.lastname: Mackway-Jones
mesh_terms: D000328:Adult; D000933:Antifibrinolytic Agents / Q000032:analysis; D002637:Chest Pain / Q000209:etiology*; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004635:Emergency Medicine / Q000295:instrumentation* / Q000379:methods; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D015588:Observer Variation; D010998:Pleurisy / Q000150:complications* / Q000175:diagnosis; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D012015:Reference Standards; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D000933:Antifibrinolytic Agents; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D