A Study to Investigate if Early Atrial Fibrillation (AF) Diagnosis Reduces Risk of Events Like Stroke in the Real-World

Inclusion Criteria:

• Medicare beneficiary either with Original or Medicare advantage

• Authorize electronic access to their healthcare claims data

• Authorize sharing of device sensor, health, and Heartline app data from their iPhoneand Apple Watch (if applicable). This includes Apple Watch and iPhone sensor datathat is not publicly available

• Willing and able to provide informed consent by electronically signing the remotee-consent directly in the Heartline app prior to any study-related activities.Electronically signing the remote e-consent indicates that he/she understands thepurpose of, and activities required for the study and is willing to participate forthe 2-year Active Engagement Phase, with continued passive collection of theirdevice and healthcare claims data for an additional 1 year in the Post-EngagementFollow-Up Phase

• Current resident of the US at the time of eligibility screening, defined byself-reported state of residence within the 50 states or the US or District ofColumbia

• Own an iPhone 6s or later with iOS Version 12.2 or later

Exclusion Criteria:

• Limited life expectancy and/or current diagnosis of terminal cancer

• Unable to confirm meeting inclusion criteria, including ability to consent andparticipate in human participant's research

• Own an Apple Watch Series 0 paired with an iPhone at the time of screeningeligibility (these participants are not eligible for any study cohorts [randomizedor observational])

• Have a confirmed diagnosis of Atrial Fibrillation (AF) at study entry and currentlytaking a direct oral anti-coagulant (DOAC) for less than (<) 30 days, currentlytaking other anti-coagulant medication(s) for AF other than a DOAC, or currently nottaking medication for AF