Journal for the Measurement of Physical Behaviour
Wrist trackers gave comparable overall activity readings
An observational comparison in 85 British and 117 Chinese adults aged 50 or older found comparable overall movement readings over up to eight days.An observational comparison in 85 British and 117 Chinese adults aged 50 or older found comparable overall movement readings over up to eight days.

Cross-sectional studyBiomarkers
Who was studiedBritish and Chinese older adults, against Axivity AX3 readings
What changedOverall activity readings were equivalent within ±10% between Matrix and Axivity trackers in British and Chinese older adults
The catchChinese participants were monitored for only two nights and one day, reducing robustness