title: Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review.
abstract: OBJECTIVE
  To summarise the evidence supporting the use of rapid d-dimer testing combined with estimation of clinical probability to exclude the diagnosis of deep venous thrombosis among outpatients.
  
  
  METHODS
  Medline (June 1993 to December 2003), the Database of Abstracts and Reviews (DARE), and reference lists of studies in English.
  
  
  METHODS
  We selected 12 studies from among 84 reviewed. The selected studies included more than 5000 patients and used a rapid D-dimer assay and explicit criteria to classify cases as having low, intermediate, or high clinical probability of deep vein thrombosis of the lower extremity among consecutive outpatients.
  
  
  METHODS
  Diagnosis required objective confirmation, and untreated patients had to have at least three months of follow up. The outcome was objectively documented venous thromboembolism. Two authors independently abstracted data by using a data collection form.
  
  
  RESULTS
  When the less sensitive SimpliRED D-dimer assay was used the three month incidence of venous thromboembolism was 0.5% (95% confidence interval 0.07% to 1.1%) among patients with a low clinical probability of deep vein thrombosis and normal D-dimer concentrations. When a highly sensitive D-dimer assay was used, the three month incidence of venous thromboembolism was 0.4% (0.04% to 1.1%) among outpatients with low or moderate clinical probability of deep vein thrombosis and a normal D-dimer concentration.
  
  
  CONCLUSIONS
  The combination of low clinical probability for deep vein thrombosis and a normal result from the SimpliRED D-dimer test safely excludes a diagnosis of acute venous thrombosis A normal result from a highly sensitive D-dimer test effectively rules out deep vein thrombosis among patients classified as having either low or moderate clinical probability of deep vein thrombosis.
authors.affiliation: Division of General Medicine, University of California at Davis, Patient Support Services Building, Suite 2400, Sacramento, California 95817, USA. Tonya.Fancher@ucdmc.ucdavis.edu
authors.forename: Tonya L
authors.initials: TL
authors.lastname: Fancher
authors.forename: Richard H
authors.initials: RH
authors.lastname: White
authors.forename: Richard L
authors.initials: RL
authors.lastname: Kravitz
mesh_terms: D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D