Patients at Risk for ThrombosisPhase 3NCT01024452
Randomized Comparison of Warfarin Dosing Quality Between the Hamilton Nomogram and a Commercial Computer System
A Phase 3 study testing DAWN AC and Hamilton Nomogram in people with Patients at Risk for Thrombosis, run by Population Health Research Institute at 1 site in Canada.
Trial summary
Randomized comparison of warfarin dosing quality between the Hamilton nomogram and a commercial computer system. Hypothesis: Mean TTR of patients managed with the commercial computer system is non-inferior to management with the validated Hamilton Nomogram. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Patients at Risk for Thrombosis
- What is being tested?
- DAWN AC and Hamilton Nomogram
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,298 participants
- Where
- 1 siteCanada
- Study dates
- Nov 2009to Aug 2010
- Phase
- Phase 3
- 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
Who may be able to join
- On warfarin maintenance therapy
- INR target range 2-3
- At least 3 historical INRs on maintenance therapy
- At least 1 historical INR in the last 3 months
Who cannot join
- Participation in another study
- On multiple pill strengths
Trial locations and contacts
1 site in 1 country.
About this study
Randomized comparison of warfarin dosing quality between the Hamilton nomogram and a commercial computer system.
Hypothesis: Mean TTR of patients managed with the commercial computer system is non-inferior to management with the validated Hamilton Nomogram.
Read the detailed description
Warfarin has a variable effect and many potential food and drug interactions. To have an optimal therapeutic effect the International Normalized Ratio (INR) needs to be maintained within the therapeutic target range. The time that a patient spends within the therapeutic target range is an intermediate quality indicator for patient outcomes and should be optimized. For this purpose, we use in our anticoagulation clinic the simple two-step Hamilton nomogram, which has been validated by Kim et al. who showed that the nomogram improved INR control for warfarin maintenance compared with expertise-based dosing in our anticoagulation clinic (see references). Computer systems are also known to outperform expertise-based dosing, but no direct comparison of a computer system with a simple nomogram has been assessed. In this single-center randomized controlled clinical trial we will compare the simple two-step Hamilton nomogram with the widely used computerized dosing management system DAWN AC regarding their effect on time in therapeutic range for patients on maintenance dosing with target range 2-3.
- Conditions
- Patients at Risk for Thrombosis
- Being tested
- DAWN AC, Hamilton Nomogram
- Keywords
- anticoagulation, warfarin, computer systems, international normalized ratio, nomograms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DAWN ACDevice
Also called DAWN AC, 4S Information Systems Ltd.
computerized dosing management system for anticoagulation clinics
Hamilton NomogramDevice
Also called Nomogram (algorithm)
simple nomogram for warfarin maintenance dosing
| Study group | Role | What they receive |
|---|---|---|
| DAWN AC | Experimental | Not described Receives: Device: DAWN AC |
| Hamilton Nomogram | Active comparator | Not described Receives: Device: Hamilton Nomogram |
What is being measured
The primary outcome is the main question the study is designed to answer.
TTR: The proportion of time a patient spends in the therapeutic INR range (2-3)
Measured: TTR calculated over the entire study period (6 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2009 (estimated)
- Study startNov 2009
- Primary completionAug 2010
- Study completionAug 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Patients at Risk for 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
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 1,298 participants (actual)
Sponsor and investigators
- Lead sponsor
- Population Health Research Institute
- Sponsor type
- University, hospital or other
- Investigators
- Stuart Connolly, MD, Principal investigator, Director, Division of Cardiology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01024452
- Sponsor's protocol ID
- 09-283
- Status last verified
- Dec 2009
- First submitted
- 1 Dec 2009
- Last updated
- 20 Jul 2011
- Results posted
- No
- Data monitoring committee
- No
Publications
Poller L, Keown M, Ibrahim S, Lowe G, Moia M, Turpie AG, Roberts C, van den Besselaar AM, van der Meer FJ, Tripodi A, Palareti G, Shiach C, Bryan S, Samama M, Burgess-Wilson M, Heagerty A, Maccallum P, Wright D, Jespersen J; European Action on Anticoagulation (EAA). A multicentre randomised assessment of the DAWN AC computer-assisted oral anticoagulant dosage program. Thromb Haemost. 2009 Mar;101(3):487-94.
PubMed 19277410Kim YK, Nieuwlaat R, Connolly SJ, Schulman S, Meijer K, Raju N, Kaatz S, Eikelboom JW. Effect of a simple two-step warfarin dosing algorithm on anticoagulant control as measured by time in therapeutic range: a pilot study. J Thromb Haemost. 2010 Jan;8(1):101-6. doi: 10.1111/j.1538-7836.2009.03652.x. Epub 2009 Oct 14.
PubMed 19840361
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Comparison of Warfarin Dosing Quality Between the Hamilton Nomogram and a Commercial Computer System
- ClinicalTrials.gov ID
- NCT01024452
- Acronym / sponsor ID
- 09-283
- Conditions
- Patients at Risk for Thrombosis
- Keywords
- anticoagulation, warfarin, computer systems, international normalized ratio, nomograms
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 1,298 participants (actual)
- Lead sponsor
- Population Health Research InstituteUniversity, hospital or other
- Study start
- Nov 2009
- Primary completion
- Aug 2010 (actual)
- Study completion
- Aug 2010 (actual)
- First posted
- 2 Dec 2009 (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.
Randomized comparison of warfarin dosing quality between the Hamilton nomogram and a commercial computer system.
Hypothesis: Mean TTR of patients managed with the commercial computer system is non-inferior to management with the validated Hamilton Nomogram.
Detailed description
Warfarin has a variable effect and many potential food and drug interactions. To have an optimal therapeutic effect the International Normalized Ratio (INR) needs to be maintained within the therapeutic target range. The time that a patient spends within the therapeutic target range is an intermediate quality indicator for patient outcomes and should be optimized. For this purpose, we use in our anticoagulation clinic the simple two-step Hamilton nomogram, which has been validated by Kim et al. who showed that the nomogram improved INR control for warfarin maintenance compared with expertise-based dosing in our anticoagulation clinic (see references). Computer systems are also known to outperform expertise-based dosing, but no direct comparison of a computer system with a simple nomogram has been assessed. In this single-center randomized controlled clinical trial we will compare the simple two-step Hamilton nomogram with the widely used computerized dosing management system DAWN AC regarding their effect on time in therapeutic range for patients on maintenance dosing with target range 2-3.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| DAWN AC | Experimental | Device: DAWN AC |
| Hamilton Nomogram | Active comparator | Device: Hamilton Nomogram |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- On warfarin maintenance therapy
- INR target range 2-3
- At least 3 historical INRs on maintenance therapy
- At least 1 historical INR in the last 3 months
Key exclusion criteria (2 listed)
- Participation in another study
- On multiple pill strengths
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DAWN ACAlso: DAWN AC, 4S Information Systems Ltd.computerized dosing management system for anticoagulation clinics | Device | DAWN AC |
| Hamilton NomogramAlso: Nomogram (algorithm)simple nomogram for warfarin maintenance dosing | Device | Hamilton Nomogram |
Primary outcome
TTR: The proportion of time a patient spends in the therapeutic INR range (2-3)
Time frame: TTR calculated over the entire study period (6 months)
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 20 Jul 2011.
- Background: PubMed 19277410Poller L, Keown M, Ibrahim S, Lowe G, Moia M, Turpie AG, Roberts C, van den Besselaar AM, van der Meer FJ, Tripodi A, Palareti G, Shiach C, Bryan S, Samama M, Burgess-Wilson M, Heagerty A, Maccallum P, Wright D, Jespersen J; European Action on Anticoagulation (EAA). A multicentre randomised assessment of the DAWN AC computer-assisted oral anticoagulant dosage program. Thromb Haemost. 2009 Mar;101(3):487-94.
- Background: PubMed 19840361Kim YK, Nieuwlaat R, Connolly SJ, Schulman S, Meijer K, Raju N, Kaatz S, Eikelboom JW. Effect of a simple two-step warfarin dosing algorithm on anticoagulant control as measured by time in therapeutic range: a pilot study. J Thromb Haemost. 2010 Jan;8(1):101-6. doi: 10.1111/j.1538-7836.2009.03652.x. Epub 2009 Oct 14.
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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.
Stuart Connolly, MD principal investigator
Director, Division of Cardiology
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing DAWN AC and Hamilton Nomogram in people with Patients at Risk for Thrombosis, run by Population Health Research Institute at 1 site 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 4 inclusion and 2 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 20 Jul 2011. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
TTR: The proportion of time a patient spends in the therapeutic INR range (2-3) (time frame: TTR calculated over the entire study period (6 months)). 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 NCT01024452, which also lists 2 linked publications.
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 20 Jul 2011; AzTrials last refreshed its copy on 31 Oct 2026.