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

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

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01024452
Enrollment
1298
Registered
2009-12-02
Start date
2009-11-30
Completion date
2010-08-31
Last updated
2011-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Patients at Risk for Thrombosis

Keywords

anticoagulation, warfarin, computer systems, international normalized ratio, nomograms

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.

Interventions

DEVICEDAWN AC

computerized dosing management system for anticoagulation clinics

DEVICEHamilton Nomogram

simple nomogram for warfarin maintenance dosing

Sponsors

Population Health Research Institute
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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

Design outcomes

Primary

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

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026