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Venous ThromboembolismNCT00788736

Predicting Bleeding Risk on Anticoagulant Therapy for Venous Thromboembolism

An observational study of Venous Thromboembolism, run by Ottawa Hospital Research Institute at 12 sites in 3 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The main objective of the study is to develop or validate a clinical prediction rule for major bleeding in patients on oral anticoagulant therapy who have been safely anticoagulated without bleeding or venous thromboembolism (VTE) recurrence for at least 3 months since diagnosis and are being considered for long-term… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Venous Thromboembolism
How many people
2,537 participants
Where
12 sitesin 3 countries
Study dates
Sep 2008to Oct 2016
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: Outpatients being treated for venous thromboembolism

Who may be able to join

  • >=18 years old
  • provoked or unprovoked venous thromboembolism
  • objectively confirmed venous thromboembolism
  • treated with an oral anticoagulant(vitamin K antagonist or new oral anticoagulant) for at least 3 months with plans to continue long-term
  • if taking a vitamin K antagonist; INR target is between 2.0-3.0
  • if taking a vitamin K antagonist; must have taken it for the last 3 consecutive weeks (minimum)

Who cannot join

  • major bleeding while taking oral anticoagulants
  • active bleeding at study enrollment
  • active cancer - current or at the time of VTE diagnosis
  • unable to provide written informed consent
  • refusal to provide written informed consent

Trial locations and contacts

12 sites in 3 countries.

12 sites in 3 countries

Canada9 sites

  • Queen Elizabeth II Health Sciences Centre

    Halifax, Nova Scotia, B3H 1V7

  • Hamilton General Hospital

    Hamilton, Ontario, L8L 2X2

  • Hamilton Health Sciences

    Hamilton, Ontario, L8V 1C3

  • London Health Sciences Centre

    London, Ontario, N6A 4G5

  • Montreal General Hospital

    Montreal, Quebec, H3G 1A4

  • Sir Mortimer B Davis Jewish General Hospital

    Montreal, Quebec, H3T 1E2

  • St. Mary's Hospital Centre

    Montreal, Quebec, H3T 1M5

  • Hopital du Sacre Coeur de Montreal

    Montreal, Quebec, H4J 1C5

  • Ottawa Hospital Research Institute

    Ottawa, Ontario, K1H 8L6

Other trials in Canada

United States2 sites

  • Lahey Clinic

    Burlington, Massachusetts, MA01805

  • Henry Ford Health System

    Detroit, Michigan, 48202

Other trials in United States

United Kingdom1 site

  • Oxford Haemophilia and Thrombosis Centre, Churchill Hospital

    Oxford, 0X3 7LJ

Other trials in United Kingdom

About this study

Official title: Development and Validation of Clinical Prediction Rules for Bleeding for Patients on Anticoagulant Therapy for Venous Thromboembolism

The main objective of the study is to develop or validate a clinical prediction rule for major bleeding in patients on oral anticoagulant therapy who have been safely anticoagulated without bleeding or venous thromboembolism (VTE) recurrence for at least 3 months since diagnosis and are being considered for long-term oral anticoagulant therapy.

Read the detailed description

Oral anticoagulant therapy for patients who are at risk of developing blood clotting problems is used by between 400,000-600,000 Canadians annually. The use of this drug represents the most common cause of patient adverse medical outcomes due to medical errors. Furthermore, many patients have adverse outcomes using these drugs because physicians are not able to predict which patients are likely to have bleeding outcomes. Much effort has gone into developing ways to predict which patients are at risk of clotting but almost no work has gone into ways of predicting which patients would be at high risk of bleeding. This information is required to balance off the risk-benefits and to enable physicians and patients to understand the risks and benefits of taking these medications. Our study will develop a tool that can be used to predict bleeding risk in patients taking oral anticoagulant therapy. It will enable more informed decision making by both physicians and patients and will result in better control of the use of these drugs. In addition, patients who are at risk for being difficult to accurately dose on oral anticoagulants will be identified through our study.

Keywords
venous thromboembolism, long-term oral anticoagulant therapy, warfarin, bleeding risk, clinical prediction rule, predictors, deep vein thrombosis, pulmonary embolism, vitamin k antagonist, side effect
Medical subject headings
Venous Thromboembolism, Venous Thrombosis, Pulmonary Embolism

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Major bleeding (International Society on Thrombosis and Haemostasis(ISTH) criteria)

    Measured: ongoing for 3-7 years with follow-up phone calls at 6-month intervals

Secondary outcomes (3)

  1. Clinically relevant non-major bleeding (International Society on Thrombosis and Haemostasis(ISTH) criteria)

    Measured: ongoing for 3-7 years with follow-up phone calls at 6-month intervals

  2. recurrent venous thromboembolism

    Measured: ongoing for 3-7 years with follow-up phone calls at 6-month intervals

  3. death (all causes)

    Measured: ongoing for 3-7 years with follow-up phone calls at 6-month intervals

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Nov 2008 (estimated)
  2. Study startSep 2008
  3. Primary completionSep 2016
  4. Study completionOct 2016

Resources

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
2,537 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00788736
Sponsor's protocol ID
OHREB 2008270-01H
Other IDs
MOP130388
Status last verified
Oct 2016
First submitted
10 Nov 2008
Last updated
27 Oct 2016
Results posted
No
Data monitoring committee
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

An observational study of Venous Thromboembolism, run by Ottawa Hospital Research Institute at 12 sites in 3 countries.

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 6 inclusion and 5 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 27 Oct 2016. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 12 sites in Canada, United States, United Kingdom. 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?

Major bleeding (International Society on Thrombosis and Haemostasis(ISTH) criteria) (time frame: ongoing for 3-7 years with follow-up phone calls at 6-month intervals). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00788736.

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 27 Oct 2016; AzTrials last refreshed its copy on 6 Nov 2026.

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