title: Accuracy of clinical decision rule, D-dimer and spiral computed tomography in patients with malignancy, previous venous thromboembolism, COPD or heart failure and in older patients with suspected pulmonary embolism.
abstract: BACKGROUND
  The diagnostic work-up of patients with suspected pulmonary embolism (PE) has been optimized and simplified by the use of clinical decision rules (CDR), D-dimer (DD) testing and spiral computed tomography (s-CT). Whether this strategy is equally safe and efficient in specific subgroups of patients is evaluated in this study.
  
  
  METHODS
  A diagnostic strategy including a CDR, DD test and s-CT was evaluated in patients with malignancy, previous venous thromboembolism (VTE), chronic obstructive pulmonary disease or heart failure and in older patients. PE was ruled out by either an unlikely CDR and a normal DD or a s-CT negative for PE. The safety of these tests was assessed by the 3-month incidence rate of symptomatic VTE in those without PE at baseline. The efficiency was evaluated by calculating the numbers needed to test for the different subgroups.
  
  
  RESULTS
  The venous thromboembolic incidence rate after the combination of an unlikely CDR and a normal DD varied from 0% (95% CI: 0-7.9%) in the 482 patients older than 75 years of age to 2% (95% CI: 0.05-10.9%) in the 474 patients with a malignancy. For s-CT these incidences varied from 0.3% to 1.8%. The number needed to test in order to rule out one patient from PE with the studied strategy was highest in cancer patients and in the elderly patients (approximately 10).
  
  
  CONCLUSIONS
  It appears to be safe to rule out PE by either the combination of an unlikely CDR and a normal DD or by a negative s-CT in various subgroups of patients with suspected PE. However, the clinical usefulness of the CDR in combination with the DD as the initial step in the diagnostic process varied among these patient groups.
authors.affiliation: Academic Medical Center, Vascular Medicine, Heibergdreef 9, 1105 AZ Amsterdam, the Netherlands. m.sohne@amc.uva.nl
authors.forename: M
authors.initials: M
authors.lastname: Sohne
authors.forename: M J H A
authors.initials: MJ
authors.lastname: Kruip
authors.forename: M
authors.initials: M
authors.lastname: Nijkeuter
authors.forename: L
authors.initials: L
authors.lastname: Tick
authors.forename: H
authors.initials: H
authors.lastname: Kwakkel
authors.forename: S J M
authors.initials: SJ
authors.lastname: Halkes
authors.forename: M V
authors.initials: MV
authors.lastname: Huisman
authors.forename: H R
authors.initials: HR
authors.lastname: Buller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002303:Cardiac Output, Low / Q000150:complications*; D003657:Decision Making; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D011655:Pulmonary Embolism / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013923:Thromboembolism / Q000150:complications*; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D