Clinical trial NCT02038530: The Designer D-dimer Deep Vein Thrombosis Diagnosis (4D) Study
Official title: D-dimer Testing, Tailored to Clinical Pretest Probability, to Minimize Initial and Follow-up Ultrasound Imaging in Suspected Deep Vein Thrombosis: A Management Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Suspected Deep Vein Thrombosis
Keywords: Deep Vein Thrombosis
Lead sponsor: McMaster University
Sponsor class: OTHER
Collaborators: name: Canadian Institutes of Health Research (CIHR)
First posted: 2014-01-16
Enrollment: 1513
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Male and females outpatients with a suspected Deep Vein Thrombosis

Brief summary: This is a cohort study that will assess a new diagnostic management strategy for suspected Deep Vein Thrombosis in outpatients.The new diagnostic strategy is designed to reduce the use of ultrasound testing on the day of presentation, and reduce repeat ultrasound testing a week after an initial normal test.

Detailed description: This is a prospective, multicentre, cohort study that will assess a new diagnostic management strategy for suspected Deep Vein Thrombosis in outpatients. The new diagnostic strategy is designed to reduce the use of ultrasound testing on the day of presentation, and reduce repeat ultrasound testing a week after an initial normal test. Less ultrasound testing will be performed because: i) more patients will have deep vein thrombosis excluded by combinations of Clinical Pretest Probability and D-dimer results on the day of presentation; and, ii) in those who still need an ultrasound, a repeat ultrasound a week after a normal result will only be performed if the D-dimer result is markedly abnormal at initial presentation. The safety of this management strategy will be established by demonstrating a very low rate of proximal Deep Vein Thrombosis or Pulmonary Embolism during 90 days follow-up in patients who had anticoagulant therapy withheld in response to negative diagnostic testing. Diagnostic test utilization will be assessed. All clinical outcomes will be adjudicated by a central independent adjudication committee that will be blind to initial D-dimer measurements and patient management.

Eligibility criteria: Inclusion Criteria:

1) Consecutive outpatients (i.e. non-hospitalized patients) with clinically suspected Deep Vein Thrombosis.

Exclusion Criteria:

1. Age less than 18 years.
2. Treated with full-dose anticoagulation for ≥ 24 hours before D-dimer was measured.
3. D-dimer level known before Clinical Pretest Probability documented.
4. Ultrasound of the leg performed before Clinical Pretest Probability was documented
5. Ultrasound was or will be performed in a patient with low Clinical Pretest Probability and a d-dimer \<1000(or equivalent), or with Moderate Clinical Pretest Probability and a D-dimer \<500 (or equivalent) (e.g. suspected bleeding).
6. Ongoing need for anticoagulant therapy.
7. Suspected Pulmonary Embolism.
8. Superficial venous thrombosis that requires, or may require, anticoagulant therapy.
9. Life expectancy less than 3 months.
10. Previously confirmed episode of Deep Vein Thrombosis.
11. Geographic inaccessibility which precludes follow-up.
12. Known pregnancy.

Primary outcomes:
measure: Confirmed symptomatic proximal Deep Vein Thrombosis
timeFrame: within 90 days
Secondary outcomes:
measure: Clinical Pretest Probability/ D-dimer/ Compression Ultrasound subgroups
timeFrame: within 90 days
measure: Death
timeFrame: within 90 days
Other outcomes:
Locations:
city: Edmonton
country: Canada
facility: University of Alberta Hospital
state: Alberta
city: Halifax
country: Canada
facility: Nova Scotia Cancer Centre
state: Nova Scotia
city: Hamilton
country: Canada
facility: Hamilton Health Sciences - Hamilton General
state: Ontario
city: Hamilton
country: Canada
facility: Hamilton Health Sciences - McMaster
state: Ontario
city: Hamilton
country: Canada
facility: St. Joseph's Healthcare
state: Ontario
city: Hamilton
country: Canada
facility: Juravinski Cancer Hospital
state: Ontario
city: London
country: Canada
facility: London Health Sciences Centre
state: Ontario
city: Ottawa
country: Canada
facility: The Ottawa Hospital Regional Centre
state: Ontario
city: Montreal
country: Canada
facility: The Jewish General Hospital
state: Quebec
city: Sherbrooke
country: Canada
facility: Centre Hospitalier Universitaire de Sherbrooke
state: Quebec
Study officials:
affiliation: ocog
name: Mark Levine, MD
role: STUDY_DIRECTOR
References: