Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2025 Apr;34(2):e14235.
doi: 10.1111/jsr.14235. Epub 2024 Jun 14.

Metrology of two wearable sleep trackers against polysomnography in patients with sleep complaints

Justine Frija  1   2   3 , Jimmy Mullaert  4   5 , Laure Abensur Vuillaume  6 , Mathieu Grajoszex  1   7 , Ruben Wanono  1 , Hélène Benzaquen  1 , Fedja Kerzabi  1 , Pierre Alexis Geoffroy  2   3 , Boris Matrot  2 , Théo Trioux  4 , Thomas Penzel  8 , Marie-Pia d'Ortho  1   2   7
Affiliations
Observational Study

Metrology of two wearable sleep trackers against polysomnography in patients with sleep complaints

Justine Frija et al. J Sleep Res. 2025 Apr.

Abstract

Sleep trackers are used widely by patients with sleep complaints, however their metrological validation is often poor and relies on healthy subjects. We assessed the metrological validity of two commercially available sleep trackers (Withings Activité/Fitbit Alta HR) through a prospective observational monocentric study, in adult patients referred for polysomnography (PSG). We compared the total sleep time (TST), REM time, REM latency, nonREM1 + 2 time, nonREM3 time, and wake after sleep onset (WASO). We report absolute and relative errors, Bland-Altman representations, and a contingency table of times spent in sleep stages with respect to PSG. Sixty-five patients were included (final sample size 58 for Withings and 52 for Fitbit). Both devices gave a relatively accurate sleep start time with a median absolute error of 5 (IQR -43; 27) min for Withings and -2.0 (-12.5; 4.2) min for Fitbit but both overestimated TST. Withings tended to underestimate WASO with a median absolute error of -25.0 (-61.5; -8.5) min, while Fitbit tended to overestimate it (median absolute error 10 (-18; 43) min. Withings underestimated light sleep and overestimated deep sleep, while Fitbit overestimated light and REM sleep and underestimated deep sleep. The overall kappas for concordance of each epoch between PSG and devices were low: 0.12 (95%CI 0.117-0.121) for Withings and VPSG indications 0.07 (95%CI 0.067-0.071) for Fitbit, as well as kappas for each VPSG indication 0.07 (95%CI 0.067-0.071). Thus, commercially available sleep trackers are not reliable for sleep architecture in patients with sleep complaints/pathologies and should not replace actigraphy and/or PSG.

Keywords: hypersomnia; insomnia; polysomnography; sleep apnea; sleep trackers.

PubMed Disclaimer

Conflict of interest statement

None of the authors has a conflict of interest to declare.

Figures

FIGURE 1
FIGURE 1
Study flow chart.
FIGURE 2
FIGURE 2
(a) Bland–Altman plots of both devices for Total sleep time (TST), wake after sleep onset (WASO), nonREM1 + 2, nonREM3. (b) Bland–Altman plots of Fitbit Alta HR for REM sleep time and latency. The red line indicates mean error, blue lines indicate 2.5 and 97.5 percentiles of the error distribution, and the black line represents a linear fit. For (a), left panel is for Withings Activite and right panel for Fitbit.
FIGURE 3
FIGURE 3
Comparison of the hypnograms given by VPSG (top), Withings Activité (middle) and Fitbit Alta HR (bottom) for one patient.
See this image and copyright information in PMC

References

    1. Berry, R. B. , Brooks, R. , Gamaldo, C. , Harding, S. , Marcus, C. , & Vaughn, B. (2012). The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications (Vol. 176). American Academy of Sleep Medicine.
    1. Chen, X. , Jin, X. , Zhang, J. , Ho, K. W. , Wei, Y. , & Cheng, H. (2023). Validation of a wearable forehead sleep recorder against polysomnography in sleep staging and desaturation events in a clinical sample. Journal of Clinical Sleep Medicine, 19(4), 711–718. 10.5664/jcsm.10416 - DOI - PMC - PubMed
    1. Chinoy, E. D. , Cuellar, J. A. , Huwa, K. E. , Jameson, J. T. , Watson, C. H. , Bessman, S. C. , Hirsch, D. A. , Cooper, A. D. , Drummond, S. P. A. , & Markwald, R. R. (2021). Performance of seven consumer sleep‐tracking devices compared with polysomnography. Sleep, 44(5) zsaa291, 1–16. 10.1093/sleep/zsaa291 - DOI - PMC - PubMed
    1. Cook, J. D. , Prairie, M. L. , & Plante, D. T. (2018). Ability of the multisensory jawbone UP3 to quantify and classify sleep in patients with suspected central disorders of Hypersomnolence: A comparison against polysomnography and Actigraphy. Journal of Clinical Sleep Medicine, 14(5), 841c848. 10.5664/jcsm.7120 - DOI - PMC - PubMed
    1. Cook, J. D. , Eftekari, S. C. , Dallmann, E. , Sippy, M. , & Plante, D. T. (2019). Ability of the Fitbit Alta HR to quantify and classify sleep in patients with suspected central disorders of hypersomnolence: A comparison against polysomnography. Journal of Sleep Research, 28(4), e12789. 10.1111/jsr.12789 - DOI - PubMed

Publication types

Grants and funding