JMIR Publications

ABSTRACT

Background:

It has been shown that consumer wrist worn wearables are able to monitor sleep parameters and thus could be used as an alternative for polysomnography. Following this, wearables gained immense popularity over the past few years. However, their accuracy has been a major concern for years.

Objective:

The objective of this review paper is to appraise the performance of three recent-generation wearable devices (Fitbit Charge 4, Garmin Vivosmart 4 and WHOOP) in determining sleep parameters and sleep stages.

Methods:

A comprehensive database search was done via Pubmed, Google Scholar and Web of Science using relevant keywords such as ‘validity’, ‘accuracy’, ‘assessment’, ‘performance’, ‘polysomnography’ in combination with ‘whoop’, ‘fitbit charge 4’, and/or ‘garmin vivosmart 4’.

Results:

The results of this review suggest that WHOOP presents the least amount of disagreement relative to polysomnography (PSG) and/or Sleep Profiler for Total Sleep Time (TST), Light Sleep (LS) and Deep Sleep (DS), but showed the largest amount of disagreement for REM sleep. The Fitbit Charge 4 and Garmin Vivosmart 4 both showed moderate accuracy in assessing sleep stages and TST compared to PSG. Only Fitbit Charge 4 showed the least amount of disagreement for REM sleep relative to PSG. In addition, the Fitbit Charge 4 showed higher sensitivities for LS, DS and REM sleep compared to the Garmin Vivosmart 4 and WHOOP.

Conclusions:

The findings of this review indicate that the devices with higher relative agreement and sensitivities for multi-state sleep, i.e., Fitbit Charge 4 and WHOOP, seem appropriate to derive suitable estimates of sleep parameters. However, the analyses regarding the multi-state categorisation of sleep indicate that all devices can benefit from further improvement for the assessment of specific sleep stages.