title: Practical diagnostic management of patients with clinically suspected deep vein thrombosis by clinical probability test, compression ultrasonography, and D-dimer test.
abstract: OBJECTIVE
  To evaluate a new noninvasive diagnostic strategy for ruling out deep vein thrombosis consisting of either a combination of low clinical probability and normal ultrasonography or a combination of moderate-to-high clinical probability, normal ultrasonography, and a normal D-dimer test.
  
  
  METHODS
  We studied 811 patients with clinically suspected deep vein thrombosis using a diagnostic management strategy that combined clinical probability, ultrasonography, and measurement of D-dimers. The primary endpoint was venous thromboembolism occurring during a 3-month follow-up.
  
  
  RESULTS
  Of the 280 patients (35%) with a low clinical probability, 30 (11%) had an abnormal initial ultrasonography and were treated. Of the other 250 untreated patients with low clinical probability and a normal ultrasonography, 5 (2%; 95% confidence interval [CI]: 1% to 5%) developed a nonfatal venous thromboembolism during follow-up. Of the 531 patients (65%) with a moderate-to-high clinical probability, 300 (56%) had an abnormal ultrasonography. Of the remaining 231 patients with a normal ultrasonography, 148 had a normal D-dimer test; none of these patients developed deep vein thrombosis during follow-up (0%; 95% CI: 0% to 3%). Of the 83 patients with an abnormal D-dimer test, 77 underwent repeat ultrasonography about 1 week later; none of the 64 patients with a second normal ultrasound developed symptomatic deep vein thrombosis during follow-up (0%; 95% CI: 0% to 6%).
  
  
  CONCLUSIONS
  This management strategy, which combines clinical probability, ultrasonography, and D-dimer measurements, is practical and safe in ruling out deep vein thrombosis in patients with clinically suspected thrombosis and reduces the need for repeat ultrasonography.
authors.affiliation: Department of General Internal Medicine, Meander Medical Center, Amersfoort, The Netherlands. L.Tick@meandermc.nl
authors.forename: Lidwine W
authors.initials: LW
authors.lastname: Tick
authors.forename: Evelien
authors.initials: E
authors.lastname: Ton
authors.forename: Theo
authors.initials: T
authors.lastname: van Voorthuizen
authors.forename: Marcel M C
authors.initials: MM
authors.lastname: Hovens
authors.forename: Ivonne
authors.initials: I
authors.lastname: Leeuwenburgh
authors.forename: Sacha
authors.initials: S
authors.lastname: Lobatto
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Stijnen
authors.forename: Cees
authors.initials: C
authors.lastname: van der Heul
authors.forename: Peter M
authors.initials: PM
authors.lastname: Huisman
authors.forename: Mark H H
authors.initials: MH
authors.lastname: Kramer
authors.forename: Menno V
authors.initials: MV
authors.lastname: Huisman
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010690:Phlebography / Q000379:methods; D011336:Probability; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018608:Ultrasonography, Doppler / Q000379:methods*; D020246:Venous Thrombosis / Q000097:blood* / Q000000981:diagnostic imaging*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D