Table 2.

Overview of consumer-grade wearable devices employed in the Nouna CHEERS, Burkina Faso, and in the Siaya HDSS, Kenya.

	Garmin vivosmart 5
Features
Steps measurements	Measured continuously, steps identified based on amplitude and periodic pattern Technology: accelerometer
Heart rate measurements	Routinely measured every 10 min Measurement frequency every 1 s (continuous heart rate mode) only in workout session or after 2 min of running Technology: photoplethysmography
Sleep measurements	Four variables calculated: total hours of sleep, sleep stages, sleep movement, and sleep score
Pulse oximeter measurements	Measures blood oxygen level (SpO2) by shining light into the skin and checking how much light is absorbed.
Wear location	Wrist
Data synchronization	Up to 1 month activity tracking, up to 3 weeks activity tracking plus extensive fitness activity use
Battery life	Up to 7 days
In-built sensor	High precision MEMS 3-axis accelerometer Photoplethysmography sensor
Connectivity	Bluetooth low energy