Randomized Controlled Feasibility Trial of the Fearon Algorithm to Improve Management of Unstable Warfarin

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

TERMINATED

Clinical Phase

PHASE1/PHASE2

Total Enrollment

42 participants

Study Classification

INTERVENTIONAL

Study Start Date

2014-11-30

Study Completion Date

2017-02-03

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Patients on warfarin but with unstable international normalized ratio (INR) will be recruited to a randomized trial comparing dosing based on an algorithm (Fearon algorithm, named after the mathematician Michael Fearon), which uses historical data to estimate patients' sensitivity to warfarin and to dose changes as well as the lag time until a dose adjustment takes effect, or to the investigators standard management Main outcome is improvement in time in therapeutic range.

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Fearon Algorithm in Warfarin Patient Self-Management

NCT03911661

Atrial Fibrillation Venous Thromboses Heart Valve Diseases

COMPLETED NA

Reinitiation of Anticoagulation After Temporary Withdrawal of Vitamin K Antagonist

NCT01348074

Atrial Fibrillation Venous Thromboembolism Heart Valve Disease +1 more

COMPLETED PHASE2

Simple Warfarin Dosing Algorithm Study

NCT01008215

Warfarin Dosing

COMPLETED NA

Prothrombin Times Outside the Therapeutic Range in Otherwise Stable Patients

NCT00814177

Atrial Fibrillation Venous Thromboembolism Ischemic Stroke +1 more

COMPLETED PHASE2

Does Low Dose Oral Vitamin K Improve International Normalized Ratio (INR) Stability?

NCT00990158

Coagulation Bleeding Thrombosis

COMPLETED PHASE3

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Patients with very variable INRs resulting in a low proportion of time in therapeutic range (TTR) have a higher risk of both bleeding complications and thromboembolic events. A good TTR is generally considered to be over 60% and "excellent TTR" is above 72% of time in range. The investigators will recruit patients with a TTR below 50%.

The Fearon algorithm provides a more thorough understanding of the individual responses to changes in warfarin dose and with a personalized nomogram for dose adjustments and timing of laboratory tests the investigators have an opportunity to improve the TTR and on a larger scale to reduce clinically important adverse events. Before embarking on a large randomized trial with this revised Fearon algorithm-derived nomogram this pilot study with a randomized, open-label design will be performed to demonstrate proof of principle.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Hypoprothrombinemia

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Dosing of warfarin according to the Fearon algorithm or routine during 6 months for patients with unstable INRs

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Fearon algorithm dosing

Warfarin adjustment using the Fearon algorithm

Group Type EXPERIMENTAL

Warfarin adjustment using the Fearon algorithm

Intervention Type OTHER

All available historical data will be used to calculate with the Fearon algorithm the individual sensitivity to warfarin and to dose changes as well as lag time until a dose adjustment reaches full effect. Based on this a personal dosing nomogram will be developed and provided to the investigator and to the patients. This nomogram will be used during 6 month but override is possible if the investigator feels that the suggestion from the nomogram is unsafe.

Standard dosing

Warfarin adjustment using standard dosing

Group Type ACTIVE_COMPARATOR

Warfarin adjustment using standard dosing

Intervention Type OTHER

Patients will receive warfarin dosing instructions from a trained nurse using fixed nomograms and computer-based dosing suggestion.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Warfarin adjustment using the Fearon algorithm

All available historical data will be used to calculate with the Fearon algorithm the individual sensitivity to warfarin and to dose changes as well as lag time until a dose adjustment reaches full effect. Based on this a personal dosing nomogram will be developed and provided to the investigator and to the patients. This nomogram will be used during 6 month but override is possible if the investigator feels that the suggestion from the nomogram is unsafe.

Intervention Type OTHER

Warfarin adjustment using standard dosing

Patients will receive warfarin dosing instructions from a trained nurse using fixed nomograms and computer-based dosing suggestion.

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Patients with mechanical heart valve prosthesis managed for the warfarin therapy by the Thrombosis Service at HHS-General Hospital.
* Treated with warfarin for at least 1 year.
* Therapeutic INR range 2.0-3.0 or 2.5-3.5.
* TTR in the lowest quartile