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

This study has been completed.
Sponsor:
Information provided by:
Population Health Research Institute
ClinicalTrials.gov Identifier:
NCT01024452
First received: December 1, 2009
Last updated: July 19, 2011
Last verified: December 2009
  Purpose

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.


Condition Intervention Phase
Patients at Risk for Thrombosis
Device: DAWN AC
Device: Hamilton Nomogram
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
Official Title: Randomized Comparison of Warfarin Dosing Quality Between the Hamilton Nomogram and a Commercial Computer System

Resource links provided by NLM:


Further study details as provided by Population Health Research Institute:

Primary Outcome Measures:
  • 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) ] [ Designated as safety issue: Yes ]

Enrollment: 1298
Study Start Date: November 2009
Study Completion Date: August 2010
Primary Completion Date: August 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: DAWN AC Device: DAWN AC
computerized dosing management system for anticoagulation clinics
Other Name: DAWN AC, 4S Information Systems Ltd.
Active Comparator: Hamilton Nomogram Device: Hamilton Nomogram
simple nomogram for warfarin maintenance dosing
Other Name: Nomogram (algorithm)

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.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

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
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01024452

Locations
Canada, Ontario
Hamilton General Hospital
Hamilton, Ontario, Canada, L8L 2X2
Sponsors and Collaborators
Population Health Research Institute
Investigators
Principal Investigator: Stuart Connolly, MD Director, Division of Cardiology
  More Information

Publications:
Responsible Party: Dr. S. Connolly, Population Health Research Institute
ClinicalTrials.gov Identifier: NCT01024452     History of Changes
Other Study ID Numbers: 09-283
Study First Received: December 1, 2009
Last Updated: July 19, 2011
Health Authority: Canada: Institutional Review Board

Keywords provided by Population Health Research Institute:
anticoagulation
warfarin
computer systems
international normalized ratio
nomograms

Additional relevant MeSH terms:
Thrombosis
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Warfarin
Anticoagulants
Hematologic Agents
Therapeutic Uses
Pharmacologic Actions

ClinicalTrials.gov processed this record on August 28, 2014