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

Population Health Research Institute (PHRI)

Status and phase: Completed; Phase 3

Conditions: Patients at Risk for Thrombosis

Treatments: Device: DAWN AC; Device: Hamilton Nomogram

Study type: Interventional

Funder types: Other

Identifiers

NCT01024452

09-283

Details and patient eligibility

About

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.

Full 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.

Enrollment: 1,298 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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1,298 participants in 2 patient groups

DAWN AC

Experimental group

Treatment:

Device: DAWN AC

Hamilton Nomogram

Active Comparator group

Treatment:

Device: Hamilton Nomogram