Suspected Deep Vein Thrombosis4DNCT02038530
The Designer D-dimer Deep Vein Thrombosis Diagnosis (4D) Study
An observational study of Suspected Deep Vein Thrombosis, run by McMaster University at 10 sites in Canada.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Suspected Deep Vein Thrombosis
- How many people
- 1,513 participants
- Where
- 10 sitesCanada
- Study dates
- Feb 2014to 15 Oct 2020
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Male and females outpatients with a suspected Deep Vein Thrombosis
Who may be able to join
- 1) Consecutive outpatients (i.e. non-hospitalized patients) with clinically suspected Deep Vein Thrombosis.
Who cannot join
- Age less than 18 years.
- Treated with full-dose anticoagulation for ≥ 24 hours before D-dimer was measured.
- D-dimer level known before Clinical Pretest Probability documented.
- Ultrasound of the leg performed before Clinical Pretest Probability was documented
- 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).
- Ongoing need for anticoagulant therapy.
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- Suspected Pulmonary Embolism.
- Superficial venous thrombosis that requires, or may require, anticoagulant therapy.
- Life expectancy less than 3 months.
- Previously confirmed episode of Deep Vein Thrombosis.
- Geographic inaccessibility which precludes follow-up.
- Known pregnancy.
Trial locations and contacts
10 sites in 1 country.
10 sites in 1 country
Canada10 sites
University of Alberta Hospital
Edmonton, Alberta, T6G 2B7
Nova Scotia Cancer Centre
Halifax, Nova Scotia, B3H1V7
Hamilton Health Sciences - Hamilton General
Hamilton, Ontario, L8L 2X2
Hamilton Health Sciences - McMaster
Hamilton, Ontario, L8N 3Z5
St. Joseph's Healthcare
Hamilton, Ontario, L8N 4A6
Juravinski Cancer Hospital
Hamilton, Ontario, L8V1C3
London Health Sciences Centre
London, Ontario, N6A 5W9
The Jewish General Hospital
Montreal, Quebec, H3T 1E2
The Ottawa Hospital Regional Centre
Ottawa, Ontario, K1H 8L6
Centre Hospitalier Universitaire de Sherbrooke
Sherbrooke, Quebec, J1G2EB
About this 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
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.
Read the 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.
- Conditions
- Suspected Deep Vein Thrombosis
- Keywords
- Deep Vein Thrombosis
- Medical subject headings
- Venous Thrombosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| No Ultrasound | Low Clinical Pretest Probability and D-dimer < 1000 ug/L; Moderate Clinical Pretest Probability and D-dimer < 500 ug/L | |
| Ultrasound Required | Low Clinical Pretest Probability and D-dimer 1000 - 3000 ug/L; Moderate Clinical Pretest Probability and D-dimer 500 - 3000 ug/L; High Clinical Pretest Probability |
What is being measured
The primary outcome is the main question the study is designed to answer.
Confirmed symptomatic proximal Deep Vein Thrombosis
The primary outcome is confirmed symptomatic proximal Deep Vein Thrombosis (including involvement of the calf vein trifurcation but not isolated more distal Deep Vein Thrombosis; or pulmonary embolism (not including isolated sub-segmental abnormalities on Computed Tomography Pulmonary Angiogram; within 90 days (± 7 days for follow-up assessment) that is not diagnosed by scheduled diagnostic testing (includes events that occur between initial and scheduled follow-up proximal ultrasound examinations).
Measured: within 90 days
Secondary outcomes (2)
Clinical Pretest Probability/ D-dimer/ Compression Ultrasound subgroups
The primary outcome in the following subgroups:
- Low Clinical Pretest Probability and D-dimer <1000 ug/L
- Moderate Clinical Pretest Probability and D-dimer <500 ug/L
- Moderate Clinical Pretest Probability and D-dimer 500 -999 ug/L
- High Clinical Pretest Probability and D-dimer <500 ug/L
- Low Clinical Pretest Probability and D-dimer 1000-2999 ug/L and negative initial ultrasound
- Moderate Clinical Pretest Probability and D-dimer 1000-2999 ug/L and negative initial ultrasound
- High Clinical Pretest Probability and D-dimer 500-1499 ug/L and negative initial ultrasound
Measured: within 90 days
Death
Death within 90 days (± 7 days for follow-up assessment).
Measured: within 90 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jan 2014 (estimated)
- Study startFeb 2014
- Primary completion17 Jun 2020
- Study completion15 Oct 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Suspected Deep Vein ThrombosisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 1,513 participants (actual)
Sponsor and investigators
- Lead sponsor
- McMaster University
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Responsible party
- Sponsor
- Investigators
- Mark Levine, MD, Study director, ocog
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02038530
- Sponsor's protocol ID
- OCOG-2013-4D
- Acronym
- 4D
- Status last verified
- Sep 2021
- First submitted
- 13 Jan 2014
- Last updated
- 28 Sep 2021
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT02038530
- Acronym / sponsor ID
- 4D / OCOG-2013-4D
- Conditions
- Suspected Deep Vein Thrombosis
- Keywords
- Deep Vein Thrombosis
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 1,513 participants (actual)
- Lead sponsor
- McMaster UniversityUniversity, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Study start
- Feb 2014
- Primary completion
- 17 Jun 2020 (actual)
- Study completion
- 15 Oct 2020 (actual)
- First posted
- 16 Jan 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| No Ultrasound | – | –Low Clinical Pretest Probability and D-dimer < 1000 ug/L; Moderate Clinical Pretest Probability and D-dimer < 500 ug/L |
| Ultrasound Required | – | –Low Clinical Pretest Probability and D-dimer 1000 - 3000 ug/L; Moderate Clinical Pretest Probability and D-dimer 500 - 3000 ug/L; High Clinical Pretest Probability |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Male and females outpatients with a suspected Deep Vein Thrombosis
Key inclusion criteria (1 listed)
- 1) Consecutive outpatients (i.e. non-hospitalized patients) with clinically suspected Deep Vein Thrombosis.
Key exclusion criteria (12 listed)
- Age less than 18 years.
- Treated with full-dose anticoagulation for ≥ 24 hours before D-dimer was measured.
- D-dimer level known before Clinical Pretest Probability documented.
- Ultrasound of the leg performed before Clinical Pretest Probability was documented
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Confirmed symptomatic proximal Deep Vein Thrombosis
Time frame: within 90 days
The primary outcome is confirmed symptomatic proximal Deep Vein Thrombosis (including involvement of the calf vein trifurcation but not isolated more distal Deep Vein Thrombosis; or pulmonary embolism (not including isolated sub-segmental abnormalities on Computed Tomography Pulmonary Angiogram; within 90 days (± 7 days for follow-up assessment) that is not diagnosed by scheduled diagnostic testing (includes events that occur between initial and scheduled follow-up proximal ultrasound examinations).
2 secondary outcomes
Clinical Pretest Probability/ D-dimer/ Compression Ultrasound subgroups
Time frame: within 90 days
Death
Time frame: within 90 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2021.
- Related InfoLink provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mark Levine, MD study director
ocog
10 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Suspected Deep Vein Thrombosis, run by McMaster University at 10 sites in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Sep 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 10 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Confirmed symptomatic proximal Deep Vein Thrombosis (time frame: within 90 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2021.