Atrial Fibrillation Data Linkage Non-Interventional Study

Study Overview
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Brief Summary
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The purpose of this study is to understand temporal changes in clinical features and functions, and the relationship with outcomes of atrial fibrillation (AF). AF is a problem with speed or pattern that the heart beats. It is the most common type of arrythmia. The study will use data linkage of a single center patient data and national claims database in Korea. This study does not include an actual patient enrollment process.

Official Title
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Temporal Changes in Clinical Characteristics and Functions, and Their Relationship With Outcomes of Atrial Fibrillation: a Retrospective Study Utilizing Data Linkage of a Signle Center Patient Data and National Claims Database in Korea

Conditions
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Atrial Fibrillation

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients had incident AF diagnosis (International Classification of Diseases 10th Revision [ICD-10]; I48) in an inpatient or outpatient setting at SNUH between 1 Jan 2010 and 31 Dec 2020 Patients aged 18 years or older on the index date Exclusion Criteria: Medical claims indicating a diagnosis code indicative of rheumatic mitral valvular heart disease, mitral valve stenosis, or prosthetic heart valve during 12 months period prior to first AF diagnosis

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Event Rate of Stroke/Systemic embolism (SE) | National Health Insurance Service(NHIS) Claims with the following ICD-10 diagnosis codes as main or all sub-diagnoses whichever came first (i.e., the first occurred event will be used): Ischemic stroke: G45.9, I63, I69.3 Hemorragic stroke: I60, I61, I62, I69.0, I69.1, I69.2 Systemic embolism: I74 Hospitalization and computed tomography (CT) or magnetic resonance imaging (MRI) codes (brain CT or MRI for ischemic stroke and hemorrhagic stroke; any CT or MRI for systemic embolism) were also required for identification. | Up to 12 months after AF diagnosis or after the start date of relevant atrial fibrillation(AF) treatment | 
| Event Rate of Major bleeding | Bleeding requiring hospitalization will be identified using hospital claims which had a bleeding diagnosis code as the first occurred ICD-10 code and will be consisted of intracranial hemorrahge (ICH), gastrointestinal (GI) bleeding, and other bleeding. Main and all sub-diagnosis codes will be used. Particularly, hospitalization and brain CT or MRI codes (as described in variable 'stroke or SE') will be needed to identify ICH. | Up to 12 months after the AF diagnosis or after the start date of relevant AF treatment | 
| All-Cause Mortality Rates | Death will be identified from mortality registration data of Statistics Korea linked to NHIS database | Up to 12 months after the AF diagnosis or after the start date of relevant AF treatment |