Randomized Comparison of Warfarin Dosing Quality Between the Hamilton Nomogram and a Commercial Computer System

July 19, 2011 updated by: Population Health Research Institute

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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 Type

Interventional

Enrollment (Actual)

1298

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8L 2X2
        • Hamilton General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • Participation in another study
  • On multiple pill strengths

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: DAWN AC
Device: DAWN AC
computerized dosing management system for anticoagulation clinics
Other Names:
  • DAWN AC, 4S Information Systems Ltd.
Active Comparator: Hamilton Nomogram
Device: Hamilton Nomogram
simple nomogram for warfarin maintenance dosing
Other Names:
  • Nomogram (algorithm)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
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)
TTR calculated over the entire study period (6 months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Population Health Research Institute

Investigators

  • Principal Investigator: Stuart Connolly, MD, Director, Division of Cardiology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2009

Primary Completion (Actual)

August 1, 2010

Study Completion (Actual)

August 1, 2010

Study Registration Dates

First Submitted

December 1, 2009

First Submitted That Met QC Criteria

December 1, 2009

First Posted (Estimate)

December 2, 2009

Study Record Updates

Last Update Posted (Estimate)

July 20, 2011

Last Update Submitted That Met QC Criteria

July 19, 2011

Last Verified

December 1, 2009

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 09-283

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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