CoaguChek XS in Antiphospholipid Antibody Syndrome (APL) Patients

Study Overview
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Brief Summary
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The purpose of this study is to see if the CoaguChek XS is accurate in measuring International Normalized Ratio (INR) in patients with Antiphospholipid Antibody Syndrome (APL) receiving warfarin therapy.

Detailed Description
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Antiphospholipid Antibody Syndrome (APL) is an autoimmune disease that increases ones risk for blood clots. Therefore, these patients receive anticoagulation therapy with warfarin. Point of care devices such as the CoaguChek XS are often used to monitor International Normalized Ratio (INR) in patients on warfarin. However, the antibodies present in patients with APL may lead to false INR results when using the CoaguChek XS. This study will compare the accuracy of the CoaguChek XS in measuring INR in patients with APL by measuring INR by the CoaguChek XS and a standard lab as a reference point. Patients on warfarin for indications other than APL will be measured by both methods as well to serve as a control group.

Official Title
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Accuracy of CoaguChek XS in Patients With Antiphospholipid Antibody Syndrome

Conditions
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Antiphospholipid Antibody Syndrome

Intervention / Treatment
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* Device: CoaguChek XS
* Procedure: Standard Lab Draw


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-65 years of age anticoagulated with warfarin for at least 1 month Diagnosis of antiphospholipid antibody syndrome for intervention arm Exclusion Criteria: any type of mental disability that would hinder their ability to give informed consent any terminal illness or any other condition that could interfere with study completion, that person will be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CoaguChek XS<br>INR measured by CoaguChek XS in patients with APL at visit 1 and visit 2, in addition to routine measure by standard lab draw | Device: CoaguChek XS<br>* CoaguChek XS will be used to measure INR in patients with APL<br>Procedure: Standard Lab Draw<br>* Patients on warfarin for any indication other than APL will measure INR by venous lab draw<br>|
| Standard Lab Draw<br>INR measured by standard lab draw at visit 1 and visit 2 for non-APL patients, in addition to routine measurement by CoaguChek XS | Device: CoaguChek XS<br>* CoaguChek XS will be used to measure INR in patients with APL<br>Procedure: Standard Lab Draw<br>* Patients on warfarin for any indication other than APL will measure INR by venous lab draw<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| International Normalized Ratio (INR) | Compare INR obtained by CoaguChek XS to INR obtained from venous lab draw. Difference of +/- 0.5 considered significant | Day 1 and Day 60 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anticoagulation, International normalized ratio, Warfarin