Related Experiment Video
Updated: Jun 19, 2026

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Published on: June 2, 2015
Management of suspected deep venous thrombosis in outpatients by using clinical assessment and D-dimer testing
C Kearon1, J S Ginsberg, J Douketis
1McMaster University Clinic, Room 401, Henderson General Hospital, 711 Concession Street; Hamilton, Ontario L8V 1C3, Canada.
Background:
When deep venous thrombosis is suspected, objective testing is required to confirm or refute the diagnosis.
Objective:
To determine whether the combination of a low clinical suspicion and a normal D -dimer result rules out deep venous thrombosis.
Design:
Prospective cohort study.
Setting:
Three tertiary care hospitals in Canada.
Patients:
445 outpatients with a suspected first episode of deep venous thrombosis.
Interventions:
Patients were categorized as having low, moderate, or high pretest probability of thrombosis and underwent whole-blood D -dimer testing. Patients with a low pretest probability and a negative result on the D -dimer test had no further diagnostic testing and received no anticoagulant therapy. Additional diagnostic testing was done in all other patients.
Measurements:
Venous thromboembolic events during 3-month follow-up.
Results:
177 (40%) patients had both a low pretest probability and a negative D -dimer result. One of these patients had deep venous thrombosis during follow-up (negative predictive value, 99.4% [95% CI, 96.9% to 100%]).
Conclusion:
The combination of a low pretest probability of deep venous thrombosis and a negative result on a whole-blood D -dimer test rules out deep venous thrombosis in a large proportion of symptomatic outpatients.
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