Study to Gather Information About the Safety of Oral Anticoagulation Drugs and How Well These Drugs Work in Real World for Patients With Non-valvular Atrial Fibrillation (Irregularly Heart Beats Which is Not Caused by a Heart Valve Problem)

Study Overview
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Brief Summary
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Oral anticoagulant (OAC) treatment with either vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) is essential in patients with atrial fibrillation for the prevention of stroke or systemic embolism (SE) a condition that happens when a blood clot forms elsewhere in the body and travels through the blood stream to plug another vessel. While there are significant number of real-world publications on the use and outcomes of NOACs for stroke prevention, evidence from routine clinical practice on the use and outcomes of reduced doses of NOACs is scarce. By evaluating routine clinical practice data from national registers in Denmark, Finland, Norway and Sweden, researchers want to gather information about the safety and how well reduced doses of NOACs work in patients with irregularly heartbeats which are not caused by a heart valve problem (non-valvular atrial fibrillation, NVAF). As a primary aim of this study, treatment with low doses of NOACs (Xarelto [generic name rivaroxaban], Eliquis [generic name apixaban] or Pradaxa [generic name dabigatran]) will be compared with VKAs (warfarin) in Nordic patients with NVAF to assess the occurrence of stroke and systemic embolism [effectiveness]) and intracranial hemorrhage a type of bleeding that occurs inside the skull [safety]).

Official Title
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Real-world Evidence for Non-valvular Atrial Fibrillation Patients Treated With Oral Anticoagulation in the Nordics

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Drug: Rivaroxaban (Xarelto)
* Drug: Apixaban
* Drug: Dabigatran
* Drug: Warfarin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with a qualifying oral OAC dispensed during the study period A primary diagnosis indicative of atrial fibrillation during the baseline period Exclusion Criteria: Age < 18 years at index date Died on index date A diagnosis of valvular disease, pregnancy, transient cause of atrial fibrillation or venous thromboembolism in the baseline period or on the index date Hip or knee replacement surgery in the 60 days prior to or on the index date A dispensed prescription of heparin or fondaparinux in the 60 days prior to or on the index date A diagnosis of end-stage kidney disease or renal replacement therapy in the baseline period or on the index date More than one dispensed OAC (any dose of rivaroxaban, apixaban, dabigatran, edoxaban, or warfarin) on the index date A dispensed prescription of an OAC (any dose of rivaroxaban, apixaban, dabigatran, edoxaban, or warfarin) during the baseline period

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Reduced dose NOAC<br>Participants with NVAF initiating treatment with reduced doses of individual non-vitamin K antagonist oral anticoagulants (NOACs) | Drug: Rivaroxaban (Xarelto)<br>* NOAC, reduced dose<br>Drug: Apixaban<br>* NOAC, reduced dose<br>Drug: Dabigatran<br>* NOAC, reduced dose<br>|
| Vitamin K antagonists (VKA)<br>Participants with NVAF initiating treatment with vitamin K antagonists (VKA) | Drug: Warfarin<br>* VKA<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with ischemic stroke (IS) or systemic embolism (SE) | Evaluation will be done in participants treated with reduced doses of individual NOACs and with VKA | Retrospective analysis from 2010 - 2018 | 
| Number of participants with intracranial haemorrhage (ICH) | Evaluation will be done in participants treated with reduced doses of individual NOACs and with VKA | Retrospective analysis from 2010 - 2018 |