ArticleSleep health2021
Changes in sleep duration, timing, and variability during the COVID-19 pandemic: Large-scale Fitbit data from 6 major US cities.
Article in Sleep health, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 62 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
62 citing papers in PubMed, 2 syntheses or guidelines pooled it, 121 citations in OpenAlex.
- Changes in Sleep Duration and Sleep Timing in the General Population from before to during the First COVID-19 Lockdown: A Systematic Review and Meta-Analysis.International journal of environmental research and public health · 2024Pooled it
- Changes in sleep quality and sleep disturbances in the general population from before to during the COVID-19 lockdown: A systematic review and meta-analysis.Frontiers in psychiatry · 2023Pooled it
- Sleep duration, sleep-wake schedules, and social jetlag among corporate employees in Japan: Age- and gender-based comparisons of wearable device data (2019-2022).Preventive medicine reports · 2026Article
- Digital Phenotyping in Health Research: Scoping Review of Methods, Gaps, and Opportunities.Journal of medical Internet research · 2026Article
- Sleep Across the Pandemic in Norwegian University and College Students: A National Repeated Cross-Sectional Analysis (2010-2023).Journal of sleep research · 2026Article
- The All of Us Research Program's wearables dataset.Nature medicine · 2026Article
- Sleepless in Society: Introducing the Concept of Public Sleep.Clocks & sleep · 2026Article
- Assessing Night-to-Night Sleep Variability as a Hallmark of Chronic Insomnia Using Longitudinal, Contactless, Mobile Sleep Monitoring: Prospective Cohort Study.JMIR formative research · 2026Article
- Monitoring sleep duration, timing, and continuity among US youth and adults in NHANES using actigraphy.Sleep health · 2026Article
- Outdoor night light exposure and sleep structure, a panel study using consumer-grade wearables.BMC public health · 2026Article
- Racial Differences in Self-Reported Sleep Continuity Disturbance, Problem Endorsement, and Daytime Dysfunction Among Black and White Non-Hispanic Adults in the United States.Nature and science of sleep · 2026Article
- Sensationalising Sleep: Perspectives and Protocols for Understanding Discourses of Sleep Health in Aotearoa New Zealand.Health promotion journal of Australia : official journal of Australian Association of Health Promotion Professionals · 2025Review
- Big data approaches for novel mechanistic insights on sleep and circadian rhythms: a workshop summary.Sleep · 2025Article
- Effects of a physical activity intervention on sleep among cancer survivors in a randomized controlled trial within the Cancer Prevention Study-3 cohort.Journal of cancer survivorship : research and practice · 2025Article
- Sleep duration and quality trajectories during the early days of the COVID-19 pandemic: a Canadian nationally representative study.BMC public health · 2025Article
- Sleep Alterations in the Population of the Metropolitan Area of Mexico and Their Association with Lifestyle Changes During COVID-19 Confinement.Clocks & sleep · 2025Article
- Patterns of dietary quality, physical activity, and sleep duration among cancer survivors and caregivers.Journal of behavioral medicine · 2025Article
- Longitudinal associations between the COVID-19 pandemic and sleep characteristics in children and parents.Frontiers in public health · 2025Article
- Allowing ad libitum sleep during overnight polysomnography affects Multiple Sleep Latency Test results in patients being assessed for hypersomnolence.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2024Article
- Sleep During the COVID-19 Pandemic: Longitudinal Observational Study Combining Multisensor Data With Questionnaires.JMIR mHealth and uHealth · 2024Observational
2 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 2 institutions in 1 country.
Funding
Abstract
The COVID-19 pandemic has resulted in societal-level changes to sleep and other behavioral patterns. Objective data would allow for a greater understanding of sleep-related changes at the population level. About 163,524 active Fitbit users from 6 major US cities contributed data, representing areas particularly hard-hit by the pandemic (Chicago, Houston, Los Angeles, New York, San Francisco, and Miami). Sleep variables extracted include nightly and weekly mean sleep duration and bedtime, and variability (standard deviation) of sleep duration and bedtime. Deviation from similar timeframes in 2018 and 2019 were examined, as were changes in these sleep metrics during the pandemic, relationships to changes in resting heart rate, and changes during re-opening in May and June. Overall, compared to 2019, mean sleep duration in 2020 was higher among nearly all groups, mean sleep phase shifted later for nearly all groups, and mean sleep duration and bedtime variability decreased for nearly all groups (owing to decreased weekday-weekend differences). Over the course of January to April 2020, mean sleep duration increased, mean bedtime shifted later, and mean sleep duration variability decreased. Changes in observed resting heart rate correlated positively with changes in sleep and negatively with activity levels. In later months (May and June), many of these changes started to drift back to historical norms.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.