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

Phase 3

Completed

• Conditions: Patients at Risk for Thrombosis
• Interventions: Device: DAWN AC; Device: Hamilton Nomogram

• Registration Number: NCT01024452
• Lead Sponsor: Population Health Research Institute

Brief 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.

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 Timeline

• Study Start: 2009-11
• Status Verified: 2009-12
• Study First Submitted: 2009-12-01
• Study First Submitted QC: 2009-12-01
• Study First Posted: 2009-12-02
• Primary Completion: 2010-08
• Study Completion: 2010-08
• Last Update Submitted: 2011-07-19
• Last Update Posted: 2011-07-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 1298

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
DAWN AC	DAWN AC	-
Hamilton Nomogram	Hamilton Nomogram	-

Primary Outcome Measures

Name	Time	Method
TTR: The proportion of time a patient spends in the therapeutic INR range (2-3)	TTR calculated over the entire study period (6 months)

Trial Locations

Locations (1)

Hamilton General Hospital; 🇨🇦 Hamilton, Ontario, Canada