Table 1.
Characteristics of studies and participants included in the meta-analysis.
| Study | Country/Continent | Participants, n | Age (years) | Female, % | Device | Algorithm | Definition of restriction measures | Observation period | Reference period |
| Azuma et al [45] 2021 | Japan/Asia | 530a | —b | 75.1 | Smartphone (iPhone Health) | Averaged data from 9 weekly averages | Declared emergency (closed schools and “stay at home” recommendation issued) | Feb 24 to Apr 26, 2020 | Feb 24 to Apr 26, 2019 |
| Bird et alc [52] 2021 | UK/Europe | 190 | Range 18-85 | 77.9 | Mobile device (eg, smartwatch) | — | Lockdown | March to May 2020 | Before March 2020 |
| Buoite Stella et al [44] 2021 | Italy/Europe | 197 | — | — | Smart technology devices (eg, smartphone, smart band, and smartwatch) | Weekly average | Lockdown | Mar 23 to Mar 29, 2020 | One week in Jan 2020 |
| Ding et alc [40] 2021 | China/Asia | 301 | — | 76.4 | Smartphone (WeChat) | Averaged data from 14-day data | Lockdown | Mar 11 to Mar 24, 2020 | Dec 28, 2019, to Jan 10, 2020 |
| Dunton et al [37] 2020 | US/North America | 149 | Range 18-74 | — | Smartphone (iPhone Health) | Monthly average | Declared “shelter in place” and “stay at home” orders | Apr 2020 | Feb 2020 |
| Gollwitzer et al [54] 2022 | US/North America | 220 | Mean 35.2 | 41.4 | Smartphone (iPhone Health) | Weekly average | Social distancing | Apr 3 to Apr 9, 2020 | Apr 3 to Apr 9, 2019 |
| He et al [41] 2020 | China/Asia | 339 | Women: mean 37.6; men: mean 36.4 | 53.4 | Smartphone (eg, Exercise Health, Keep) | Average data during the observation period | Semilockdown (assembly was suspended, and curfew and quarantine measures were implemented in some districts) | Jan 27 to Mar 1, 2020 | Dec 23, 2019, to Jan 26, 2020 |
| Henriksen et ald [49] 2021 | Norway/Europe | 113 | Mean 40.6 | 56.2 | Wearable activity trackers (Apple, Fitbit, Garmin, Oura, Polar, Samsung, and Withings), and smartphones (Google Fit and Apple Health) | Monthly average | Lockdown | Mar 13 to Mar 31, 2020 | Mar 2019 |
| Hudgins et al [53] 2021 | US/North America | 80 | Mean 32.2 | — | Wearable activity trackers | Monthly average | Academic break in 2020, during which the university transitioned to remote learning | 30 days after spring break 2020 | 30 days before spring break 2020 |
| Ji et al [42] 2022 | China/Asia | 781 | — | — | — | — | — | — | — |
| Karageorghis et al [38] 2021 | US/North America | 1029 | Mean 40.7 | 76.4 | Electronic devices | Self-reported daily steps based on devices’ records | Declared “stay at home” order | Mar 21 to Apr 7, 2020 | Before Mar 21, 2020 |
| Karageorghis et al [38] 2021 | UK/Europe | 392 | Mean 51.2 | 80.1 |
|
|
National lockdown | After Mar 23, 2020 | Before Mar 23, 2020 |
| Karageorghis et al [38] 2021 | France/Europe | 734 | Mean 37.7 | 76.0 |
|
|
National lockdown | After Mar 16 2020 | Before Mar 16 2020 |
| Karageorghis et al [38] 2021 | Australia/Oceania | 386 | Mean 42.5 | 72.5 |
|
|
Interstate border closurese | After Mar 19, 2020 | Before Mar 19, 2020 |
| Obuchi et al [46] 2021 | Japan/Asia | 2587 | — | 76.7 | Smartphone | Weekly average | Declared emergency (closed schools and issued “stay at home” recommendation) | Apr 21 to Apr 27, 2020 | Apr 30 to May 6, 2019 |
| Ong et alc [20] 2021 | Singapore/Asia | 1824 | Mean 30.9 | 51.6 | Wearable activity tracker (Fitbit) | Averaged data from 3-week data | Lockdown | Apr 7 to Apr 27, 2020 | Jan 2 to Jan 22, 2020 |
| Park et al [50] 2021 | South Korea/Asia | 1163a | Mean 23.7 | 45.6 | Smartphone (iPhone Health) | Monthly average | Level 2.5 (gatherings of more than 50 people indoors and more than 100 people outdoors were prohibited) | Sep 2020 | Jan to Dec 2019 |
| Sañudo et al [51] 2020 | Spain/Europe | 20 | Mean 22.6 | 47 | Xiaomi Mi Band 2 wrist-worn accelerometer | Weekly average | Lockdown | One week, between Mar 24 and Apr 3, 2020 | One week in Feb 2020 |
| Sato et al [47] 2022 | Japan/Asia | 2846 | Mean 45.9 | 59.6 | Accelerometer (Panasonic) | Average data during the observation period | Declared emergency (closed schools and issued “stay at home” recommendation) | Apr 7 to May 13, 2020 | Jan 1 to Feb 29, 2019 |
| Wang et alc [19] 2020 | China/Asia | 3544 | Mean 51.6 | 34.6 | Smartphone (WeChat) | Monthly average | Declared emergency (physical distancing measures were issued) | Jan 22 to Feb 20, 2020 | Feb 2 to Mar 3, 2019 |
| Woodruff et al [39] 2021 | Canada/North America | 121 | Mean 36.2 | 80 | Wearable activity trackers (Apple, Fitbit, Samsung, Garmin) | — | Declared emergency (physical distancing measures were issued) | Based on the date each person began physically distancing/self-isolating | Based on the date each person began physically distancing/self-isolating |
| Yamada et al [48] 2023 | Japan/Asia | 678 | — | — | Wearable activity tracker (EW-NK63) | Monthly average | Declared emergency (closed schools and issued “stay at home” recommendation) | April 2020 | April 2019 |
| Zhu et al [43] 2021 | China/Asia | 1029 | Range 18-76 | 69.1 | Smartphone (WeChat) | Self-reported daily steps based on smartphone’s records | Lockdown | Three months after entering isolated life | Jan 21 to Jan 25, 2020 |
aObservations are reported instead of participants for these studies, because of uncertainty about the number of participants who were double counted (before and after the confinement period).
bNot available.
cData for daily steps were obtained from the authors for these studies.
dOnly 106 of 113 participants provided characteristics in this study.
e“Interstate border closures” means that Australia closed its borders to all noncitizens and nonresidents. This started on March 20, 2020, with no exceptions for Australian citizens, permanent residents, or their immediate families. Furthermore, a lockdown policy started in Australia on March 23, 2020.