Prospective Trial of a Validated Algorithm for Warfarin Dosing

Study Overview
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Brief Summary
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The aim of this study is to perform a randomized trial comparing the use of the algorithm, with dosing of warfarin in standard manual dosage clinical practice, in a high quality anticoagulant setting (PSM). This is done for safety concerns and to ensure good performance of the algorithm when used in a clinical setup. The results from the study are expected to increase our knowledge of efficacy by using the algorithm in clinical practice.

Official Title
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Prospective Trial of a Validated Algorithm for Warfarin Dosing

Conditions
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Anticoagulation

Intervention / Treatment
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* Other: Experimental
* Other: Active Comparator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Participants will be those ≥18 years old, must refer to Trombosecenter Aalborg and have to be educated as PSM patient Have to be treated for at least 1 month and willing to sign informed consent Exclusion Criteria OAT treatment with phenprocoumon Lack of ability to handle the interface on the software used in the study (evaluated by the investigator present at the information meeting) Pregnancy Those with severe co-morbidities (e.g., creatinine > 2.5, hepatic insufficiency, active malignancy, advanced physiological age, noncompliance risk, expected survival <6 months), and physician or patient preference.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: self-managing warfarin<br>self-managing warfarin patients who are educated in dosing warfarin to achieve target INR value | Other: Active Comparator<br>* Participants were (previously) educated in monitoring the INR values and to adjust the warfarin treatment accordingly to achieve a designated target INR range.<br>* Other names: self-managing warfarin;|
| Experimental: algorithm-suggested warfarin dosing<br>algorithm-suggested warfarin dosing, where the participants are provided with a dosage suggestion of their warfarin dosage (calculated dose) to achieve target INR | Other: Experimental<br>* The algorithm is based on a model, which is designed to handle time series of daily warfarin intakes and INR values measured at designated time points. Based on these inputs the model is able to suggest a warfarin maintenance dose to achieve target INR value. Model parameters are initially set to population values and gradually, as data is entered into the model, these parameters become patient specific.<br>* Other names: algorithm-suggested warfarin dosing;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time in therapeutic range | The primary study endpoint, TTR, was calculated according to the Rosendaal method | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Log of the variance growth rate | As a measure of INR variability we used log of the variance growth rate (logVGR) defined by Fihn et al. | 6 months |