Management of suspected deep venous thrombosis in outpatients by using clinical assessment and D-dimer testing.
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.


METHODS
Prospective cohort study.


METHODS
Three tertiary care hospitals in Canada.


METHODS
445 outpatients with a suspected first episode of deep venous thrombosis.


METHODS
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.


METHODS
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%]).


CONCLUSIONS
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.
Kearon
C
C
McMaster University Clinic, Room 401, Henderson General Hospital, 711 Concession Street; Hamilton, Ontario L8V 1C3, Canada.
Ginsberg
J S
JS
Douketis
J
J
Crowther
M
M
Brill-Edwards
P
P
Weitz
J I
JI
Hirsh
J
J
D000553:Ambulatory Care; D002170:Canada; D004797:Enzyme-Linked Immunosorbent Assay; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006801:Humans; D011446:Prospective Studies; D018570:Risk Assessment; D020246:Venous Thrombosis / Q000175:diagnosis*
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D