Rationale and design of a large-scale, app-based study to identify cardiac arrhythmias using a smartwatch: The Apple Heart Study

Figure 1. Study design. Overview of study flow with example tachograms and screenshots. The tachograms are not visualized or provided to the participant, and analyses are run in the background.

Figure 2. Participant study engagement screenshots. Number of days the participant has been in the study and total number of tachograms recorded for that participant as seen within the app on the phone (left) and watch (right).

Figure 3. Cumulative participant enrollment per week based on operational metrics. [1] Study launch with media promotion (Apple press release, App store feature). [2] Waiting room eliminated. All individuals that had been in the waiting room were invited into the study. Enrollment metering ceased. [3] Single recruitment email sent.