Table 1

Characteristics of included studies

StudyStudy designStudy populationSample sizeMean ageFemale (%)Description of lockdownClassification of lockdownOutcomes of interest assessed
Adibelli and Sümen, 2020, Turkey84Cross-sectionalChildren aged 7–13 years5979.87 years (1.99)55.8%Implemented lockdown, suspended formal education and practised distance educationStrict lockdownSleep quality
Aguilar-Farias et al, 2020, Chile39Cross-sectionalChildren aged 1–5 years31573.10 years (1.38)49.4%All schools closed, work-from-home strategies, all national parks closed, lockdowns and curfews in some districtsStrict lockdownPhysical activity, screen time, sleep duration, sleep quality
Alonso-Martínez et al, 2021, Spain40Cohort (Prospective)Preschoolers aged 4–6 years from schools21Not reported42.9%Mandatory home lockdown; closure of non-essential businesses and schoolsStrict lockdownPhysical activity, sleep duration, sleep quality
AMHSI, 2020, Multicountry70Cohort (Prospective)Healthy volunteers with stay at home for 14 days or more aged 15–18 (subgroup)3078Not reported43.5%Stay-at-home for 14 days or moreStrict lockdownSleep duration
Araby et al, 2021, Egypt80Cross-sectionalSchool children aged 614 years1507Not reported40.9%Total lockdown measuresStrict lockdownSleep quality
Bingham et al, 2021, UK41Cohort (Prospective)Children aged 9–13 years6439.10 years (1.10)49.4%Extreme restrictions on movement, people not allowed to leave their residence except for reasonable excuses such as buying food and medical supplies, people could also go out for a short exercise (60 min) daily, all playgrounds and indoor and outdoor play facilities closed, schools closed for most children except for vulnerable children and children of key workersStrict lockdownPhysical activity
Bronikowska et al, 2021, Poland42Cohort (Prospective)Adolescent Polish youths12715.40 years (0.50)52.0%From 1 to 20 April, children below 18 years were not allowed to leave their home without their guardians, later they could go out maintaining 2 m distance and covering their mouth and nose, sports facilities were closed until 4 MayStrict lockdownPhysical activity
Brzek et al, 2021, Poland43Cohort (Prospective)Children aged 3–5 years1316Not reported55.6%School closure, ban on public gatherings,Strict lockdownPhysical activity, screen time, sleep duration
Cacioppo et al, 2020, France85Cross-sectionalChildren with physical disabilities aged 0–18 years10009.50 years (4.80)46.0%Lockdown in France from 17 March 2020 to 11 May 2020UnclearPhysical activity, sleep quality
Çakıroğlu et al, 2021, Turkey105Cross-sectional (Repeated)Children and adolescents aged 10–18 yearsBefore: 581
During: 410
Not reportedBefore: 43.9%
During: 56.3%
Temporary closure of all educational institutions, sports centres, cultural venues, and entertainment centres; curfew imposed for children below 20 years as of 4 April 2020; work from home policies enacted by many private and public institutions, including schoolsVery strict lockdownScreen time (digital gaming)
Cardy et al, 2021, Canada86Cross-sectionalCanadian children with autism spectrum disorder (ASD) aged 19 years and youngerASD: 127ASD: 11.70 years (4.06)ASD: 78.0%School closure, prolonged exposure to the pandemic response (2- to 3-months)UnclearScreen time
Carrillo-Diaz et al, 2021, Spain87Cross-sectional (for physical activity and media use)Adolescents aged 11–17 years who attended appointments at private clinics (dental wear)21314.00 years (1.90)54.5%Obligatory total lockdown from 16 March to 4 MayStrict lockdownPhysical activity, media use
Censi et al, 2021, Italy44Cross-sectionalItalian children aged 2–11 years1027Not reported46.0%Rigorous isolation measures and confinement at home enforced by the Italian government through the decree from the second week of March 2020 until 18 MayStrict lockdownPhysical activity, screen time
Cellini et al, 2021, Italy71Cross-sectionalChildren 6–10 years2997.96 years (1.36)46.5%National lockdown; all schools and nonessential businesses closed; people not allowed to leave their homes unless for an essential reason, remote workStrict lockdownSleep duration, bedtime, rise time, sleep quality
Cerasuolo et al, 2021, Italy77Cross-sectionalItalian toddlers (0–3 years) and preschoolers (4–5 years)112 (Toddlers = 61, Preschoolers = 51)3.09 years (1.88)41.7%Nationwide lockdown with severe control measures such as home confinement, movement restrictions, smart remote working, and temporary closure of non-essential businesses and schools; people allowed to leave their residence only for demonstrated necessities, such as health issues, basic needs and workStrict lockdownBedtime, rise time, sleep quality
Chaffee et al, 2021, USA45Cohort (Prospective)Students in grades 9 or 10Baseline: 1423
Follow-up: 1006
Not reportedFollow up: 62.0%Statewide stay-at-home order in California declared on March 19, 2020Strict lockdownPhysical activity
Chakraborty et al, 2021, India69Cross-sectionalChildren and adolescents aged 3–15 years6458.30 years (3.50)48.4%Nationwide lockdown from 25 March 2020, initially for 21 days and extended many times with some relaxations; during the lockdown, all schools, shopping malls, local markets, workplaces and public transports completely shut down except for emergency services such as hospitals, petrol pumps, groceries, etc.Strict lockdownScreen time (Media use)
Chambonniere et al, 2021, France46Cross-sectionalFrench children and adolescents aged 6–17 years6491Not reported57.6%National lockdown from 14 March 2020, for 55 days, complete closure of all primary and secondary schools shifting all the teaching activities to virtual modeStrict lockdownPhysical activity, screen time
Cheng et al, 2021, Malaysia88Cross-sectionalChildren and adolescents with type 1 (T1DM) and type 2 diabetes mellitus (T2DM) aged less than 18 years123 (T1DM = 93, T2DM =3 0)T1DM: 11.08 years (3.47)
T2DM: 13.81 years (2.03)
Total: 56.1%
T1DM: 52.7%
T2DM: 66.7%
18 March 2020 to 3 May 2020: Total nationwide lockdown (known as Movement Control Order) forcing the closure of schools and all non-essential businesses and restricting outdoor sports, leisure activities, and travel between states and districts; followed by partial lockdown with the gradual lifting of restrictions in phases (4 May to 9 June: Conditional Movement Control Order and 10 June 2020 to 31 March 2021: Recovery Movement Control); travel restriction and schools closure remained throughoutStrict lockdownPhysical activity, screen time, sleep duration
Clarke et al, 2021, UK47QualitativePreschool aged children (3–5 years)20 parentsNot reported16 mothers, 4 fathers‘Stay at home’ order allowing people to leave the house only to buy essential supplies, attend medical appointments, or exercise once a day; schools and nurseries closed except for vulnerable or ‘keyworker’ children; non-essential businesses closedStrict lockdownPhysical activity, screen time, sleep quality
DiGiorgio et al, 2020, Italy78Cross-sectionalChildren aged 2–5 years2454.00 years43.7%National lockdown; temporary closure of schools and non-essential businesses, movement restriction, work from homeStrict lockdownBedtime, wake time, sleep quality
Di Giorgio et al, 2021, Italy89Cross-sectionalChildren with Fragile X-Syndrome, aged 2–16 years539.71 years (4.14)15.1%Total lockdown: home confinement, movement restriction, smart remote work and temporary closure of non-essential businesses and schoolsStrict lockdownPhysical activity, sleep duration, sleep quality
Dondi et al, 2021, Italy81Cross-sectionalChildren aged ≤18 years, including children with disabilities, ASD, chronic diseases and specific learning disabilities6210Not reportedNot reportedTotal lockdown from 11 March 2020 to 18 May 2020, during the first wave of COVID-19 pandemicStrict lockdownSleep quality
Esentürk, 2020, Turkey90QualitativeChildren with ASD aged 9–16 years1012.10 years50.0%Reduction of public transport, closure of all schools, cancellation of arts and sports events, mandatory quarantine for the people who traveled from abroad, closure of public places such as cafes/cinemas/the mall, curfews for the citizens over 65, under 20 and those with chronic illnessesVery strict lockdownPhysical activity
Eyler et al, 2021, USA62QualitativeParents of children aged 5–12 yearsIn 16 interviews, 16 parents reported on 23 childrenNot reported56.5% (Children)COVID-19 stay-at-home ordersStrict lockdownPhysical activity, screen time
Eyler et al, 2021, USA48Cross-sectionalChildren aged 5–12 years2458.10 years48.6%Compulsory stay-at-home orders issued by 42 states and territories from 1 March 2020 to 31 May 2020; school closure; physical education and after-school sports programmes halted or limited to virtual options; other extracurricular, community-based opportunities for physical activity halted; outdoor spaces such as parks and playgrounds also closedStrict lockdownPhysical activity
Garcia et al, 2021, USA91Cohort (Prospective)Adolescents with ASD aged 14–19 years916.87 years (1.36)11.1%Most people in the US forced to remain in quarantine for several weeks to months, resulting in a complete disruption of daily routines for most school-aged children and adolescentsStrict lockdownPhysical activity, screen time, sleep duration
Guo et al, 2021, China49Cross-sectionalChinese students in primary, secondary and high schools10 461Not reported49.9%Home confinement, school closures, social distance measures, restriction on group activities, team sports or playgrounds, home confinementStrict lockdownPhysical activity, screen time, sleep duration
Kaditis et al, 2021, Multi-country75Cross-sectionalChildren aged less than 18 years845Not reported45.8%Governments and local authorities urged their citizens to remain at home, implementation of strict social distancing rules, closure of enterprises and schoolsStrict lockdownBedtime, wake time, sleep duration
Kahn and Gradisar, 2021, USA72Cohort (Prospective)Infants 6–18 months old610 (2019 Cohort: 293, 2020 COVID-19 Cohort: 317)2019: 11.8 months (3.5)
2020: 11.9 months (3.7)
2019: 51.5%
2020: 49.8%
Stay-at-home orders imposed in the USA (Los Angeles and San Francisco: 19 March, Chicago: 21 March, New York: 22 March, and Dallas and Houston: 2 April)Strict lockdownNighttime sleep duration, morning rise time
Kołota and Glabska, 2021, Poland63Cross-sectionalAdolescents aged 10–16 years1334Not reported53.3%Primary schools closed, and lessons shifted to online mode since 12 March 2020 and was continuing at the time of the survey (June 2020), during that period, people were advised to limit personal contact and not leave their homes until necessary, wearing a face mask in public places made mandatory on 16 April 2020Strict lockdownPhysical activity, screen time
Lavigne-Cerván et al, 2021, Spain82Cross-sectionalChildren and adolescents aged from 6–18 years102810.34 years (3.64)46.6%State of alarm declared; educational institutions and many workplaces closed; entire population forced to stay indoorsStrict lockdownSleep quality
Li et al, 2021, China73Cohort (Perspective)Teenagers aged 14–19 years102015.87 years (0.74)58.9%Social isolation policy, people forced to remain homebound, national school closures and study online for nearly three monthsStrict lockdownSleep duration, sleep quality
Lim et al, 2020, Singapore50Cross-sectionalChildren aged between 3 and 16 years593Median: 8.00 years, IQR: 6.00–11.00)Not reportedNational lockdown (called ‘Circuit Breaker’)- closure of all non-essential services and workplaces, including schools, stores, and recreational facilities; online learningStrict lockdownPhysical activity, screen time, sleep duration, bedtime, wake time, sleep quality
Liu et al, 2020, China74Cross-sectional (Repeated)Preschoolers aged 4–6 yearsBefore COVID-19: 1619
During COVID-19: 436
Before COVID-19: 5.03 years
During COVID-19: 5.01 years
Before COVID-19: 49.5%
During COVID-19: 51.1%
Nationwide school closure; all citizens, including children required to stay indoorsStrict lockdownSleep duration, bedtime, wake time, sleep quality
Lokhandwala et al, 2021, USA76Cohort (Perspective)Children aged 36–70 months1656.4 months (10.8)18.8%Shutdown of schools and non-essential businesses as part of the state of Massachusetts’s stay-at-home advisoryStrict lockdownSleep duration, wake-up time
López-Bueno et al, 2020, Spain3Cross-sectionalChildren and adolescents aged 3–16 years8609.60 years (3.90)49.2%Strict confinement (minors not allowed to go out except for medical reasons, those aged 15 and over could go out once a day for shopping or taking a dog for a short walk, maintaining a social distance of 1.5 mVery strict lockdownPhysical activity, screen time, sleep duration
Luijten et al, 2021, Netherlands83Cross-sectional (Repeated)Dutch children and adolescents aged 8–18 yearsBefore lockdown: 2401
During lockdown: 844
Before lockdown: 13.10 (3.14)
During lockdown: 13.40 (2.80)
Before lockdown: 49.7%
During lockdown: 52.6%
12 March 2020—people asked to stay inside and work from home as much as possible and to follow social distancing (1.5 m), all large events canceled; partial lockdown implemented on March 15— closure of all schools and child care facilities (except for children of essential care workers), as well as sports and leisure facilities, bars, and restaurants; children still allowed to play outside; May 11—primary schools partially reopened, and on June 2 secondary schools followedStrict lockdownSleep quality
Łuszczki et al, 2021, Poland51Cross-sectional (Repeated)Polish children and adolescents aged 6–15 years1016
(Before lockdown: 376
During lockdown: 641)
Before: 10.51 years (2.13)
During: 10.79 years (2.02)
Before lockdown: 50.3%
During lockdown: 51.9%
March 10–12: cancellation of mass events and closure of all educational institutions and offices; measures further tightened on 25 March, limiting religious gatherings and forbidding non-essential travelStrict lockdownPhysical activity, media use, sleep duration and quality
Masi et al, 2021, Australia92Cross-sectionalChildren with neurodevelopmental disability aged 2 to 17 years3029.70 years33.1%At the time of the study, state governments had started easing restrictions, with further easing imminent in most statesMild lockdownPhysical activity, media use, sleep quality
Medrano et al, 2021, Spain52Cohort (Prospective)Schoolers aged 8 to 16 yearsBefore lockdown: 291
During lockdown: 113
Before lockdown: 12.10 years (2.90)
During lockdown: 12.00 years (2.60)
Before lockdown: 47.8%
During lockdown: 48.7%
One of the strictest alarm state, schools closed, mandatory home confinement for childrenStrict lockdownPhysical activity, screen time, sleep duration
Minuto et al, 2021, Italy93Cohort (Retrospective)Young T1D patients aged 6–39 years (outcomes available for sub-groups)Total: 202
6–18 years: 107
Total: 18.30 years (6.43)Total: 47.0%Started with the first emergency measures such as suspension of schools, sports activities, and meetings, followed by a national quarantine from March 9, 2020, restricting movement except for necessityStrict lockdownPhysical activity
Mitra et al, 2020, Canada53Cross-sectionalChildren and youth aged 5–17 years1472
(5–11 years: 693, 12-17 years:779)
Children: 8.12 years (2.04)
Youth: 14.85 years (1.68)
47.0%Physical distancing rules (two or more meters), social gatherings prohibited, team sports canceled, playgrounds and parks closed, most public schools closedStrict lockdownPhysical activity, screen time, sleep duration, sleep quality
Monteiro et al, 2021, Portugal106Cross-sectionalChildren aged 6 months to 6 years and 12 months19342.9 months (20.6)44.0%Schools closed and shifted to online learning; outings limited to essential activities such as buying food, going to the pharmacy, and running and bike riding for a short distance when sone alone; children allowed to play outdoor for short periodsStrict lockdownScreen time
Moore et al, 2020, Canada27Cross-sectionalChildren and youth aged 5-17 years1472
(5-11 years: 53%, 12-17 years: 47%)
Children: 8.12 years (2.04)
Youth: 14.85 years (1.68)
47.0%Physical distancing rules (two or more meters); limited community and social gatherings, sport, and playground and park use; most schools closed, and classroom lessons replaced by homeschooling and online learningModerate lockdownPhysical activity, screen time, sleep duration, sleep quality
Morgül et al, 2020, UK54Cross-sectionalChildren aged 5 to 11 years9277.45 years (2.04)45.5%Lockdown started on 23rd March, 2020; nationwide school closure except for children of key workersModerate lockdownPhysical activity, screen time, sleep duration
Munasinghe et al, 2020, Australia55Cohort (Prospective)Young people aged 13-19 years582Median: 17.00 years (Interquartile range: 16.00-18.00)79.9%Physical distancing policies implemented, people requested to stay at their homes wherever possible and limit their travel to obtain essential goods and services; school closuresMild lockdownPhysical activity, screen time, sleep duration
Nathan et al, 2021, Australia20Cross-sectionalChildren aged 5 to 9 years from Western Australia1576.90 years (1.70)45.9%State of emergency declared; indoor sporting facilities and playgrounds closed; people told to stay at home except for buying food and necessities, seeking medical care, work, study, and exercise complying with public gathering requirementsMild lockdownPhysical activity, screen time, sleep duration
Ng et al, 2020, Ireland9Cross-sectionalIrish adolescents aged 12-18 years1214Not reported72.0%Social distancing rules, closure of schools, online schooling from home, club training canceled, going outdoors not allowed apart from one walk a dayStrict lockdownPhysical activity
Oflu et al, 2021, Turkey107Cross-sectionalHealthy children aged 3–10 years applying to the pediatrics clinics for outpatient care2536.30 years (1.40)47.0%Schools and nurseries closed; curfew implemented for those under the age of 20Very strict lockdownScreen time
Okely et al, 2021, Multi-country26Cohort (Prospective)Children aged 3 and 4 years948Before COVID-19: 4.40 years (0.60)
During COVID-19: 5.20 years (0.60)
49.0%41% of the participants faced high (Early Childhood Education and Care (ECEC) services closed, people not allowed to go out in public to exercise), 46% moderate (ECECs closed, advised to limit time outside), and 13% low levels of restrictions (pre-schools open or available to children of essential workers, allowed to go out in public for exercise).Strict lockdownPhysical activity, screen time, sleep duration and quality
Ozturk Eyimaya and Yalçin Irmak, 2021, Turkey68Cross-sectionalChildren studying in grades 1-8, aged 6-13 years11159.03 years (1.95)53.4%All schools closed and shifted to remote education, temporary lockdown on children and young people under the age of 20Very strict lockdownScreen time
Pietrobelli et al, 2020, Italy94Cohort (Prospective)Children and adolescents with obesity aged 6-18 years4113.00 years (3.10)46.3%Three weeks’ national lockdown, mandatory home confinementStrict lockdownPhysical activity, screen time, sleep duration
Pombo et al, 2021, Portugal56Cross-sectionalChildren aged 13 years2159Not reported48.3%March 16: Nationwide closure of schools, companies, and non-essential public services; March 18: state of emergency declared – movement restrictions on the entire population, all non-essential businesses closed except supermarkets, pharmacies, and gas stations, and only take-aways allowed from restaurantsStrict lockdownPhysical activity, screen time
Ramos Socarras et al, 2021, Canada79Cross-sectionalAdolescents and young adults aged 12 to 25 years (outcomes available for sub-groups)Total 498 (12-14 years: 108, 15-17 years: 141)Total sample: 18.17 years (3.72)76.3% (12-14 years: 74.6%, 15-17 years: 79.8%)March 13, 2020: state of emergency and the lockdown declared with severe restrictions in the first month, including the closure of schools, public places (casinos, gyms, bars, public pools, arenas, ski centres, theaters, etc), and non-essential businesses such as restaurants, daycare, shopping centres, hair salon, and prohibition of gatherings and travel between different regions; restrictions made more flexible from the beginning of May 2020Strict lockdownSleep duration, sleep quality
Ruíz-Roso et al, 2020, Multi-country57Cross-sectionalAdolescents aged 10 years to 19 years and 11 months726Not reported59.6%Lockdown in Italy, Spain, Colombia, and Brazil; no national lockdown in Chile, but mandatory quarantine in some communitiesStrict lockdownPhysical activity
et al, 2021, Brazil58Cross-sectionalChildren aged less than 13 years816Not reported49.4%Social isolation, face-to-face school activity fully suspended, long period of movement restriction without any organised physical activity or possibility to play outdoorsStrict lockdownPhysical activity, screen time, sleep duration
Saxena et al, 2021, India108Cohort (Prospective)School children aged 9-14 years1237Baseline: 11.88 years (1.01)40.9%School closureUnclearScreen time
Schmidt et al, 2020, Germany19Cohort (Prospective)4-to 17-year-olds1711Before lockdown: 10.36 years (4.04)
During lockdown: 11.34 years (4.06)
49.8%Schools, sports clubs, gyms, and recreational facilities closed; physical distancing measures implemented; playing outdoors allowed if done alone or with family membersModerate lockdownPhysical activity, screen time
Sciberras et al, 2020, Australia95Cross-sectionalChildren with ADHD aged 5-17 years21310.59 years (3.10)23.6%Citizens required to stay at home except for essential reasonsModerate lockdownPhysical activity, screen time
Serra, 2021, Italy67Cohort (Perspective)Italian children and adolescents aged 6 to 18 years18414.84 years (2.73)71.7%During the second wave of the pandemic, the country divided into red, orange, and yellow zones based on the scenario of epidemiological risk; in areas with increased risk of COVID-19 spread, people’s movement and economic and social activities more limited; intermittent school lessons in physical presence for children of infant schools, primary schools and some lower secondary schools and only online lessons for other lower secondary school children and high school adolescentsModerate lockdownScreen time
ten Velde et al, 2021, Netherlands64Cohort (Retrospective)Cohort A: children aged 4 to 18 yearsCohort A: 10210.50 years (3.60)57.6%Nationwide shutdown of schools, sports clubs, bars, and restaurantsStrict lockdownPhysical activity, screen time
Cohort B: primary school children (7-12 years)Cohort B: 13110.20 years (0.90)56.5%
Tornaghi et al, 2020, Italy65Cross-sectionalItalian youngsters aged 15-18 years from North-western Lombardy high schools1259 (Before and during lockdown)Not reported76.9%Initially limited and then suspended nonessential movement, except activities practised within a 200 m home-block area maintaining a distance of at least 1 mStrict lockdownPhysical activity
Tso et al, 2020, Hong Kong109Cross-sectionalChildren aged 2-12 years292026.50 years (2.84)48.6%All schools closedUnclearScreen time
Tulchin-Francis et al, 2021, USA59Cross-sectionalChildren aged 3 to 18 years1310Not reported51.3%government-mandated activity restriction, including social distancing and stay-at-home ordersStrict lockdownPhysical activity
Türkoğlu et al, 2020, Turkey96Cross-sectionalChildren and adolescents aged 4-17 years diagnosed with ASD467.89 years17.4%Schools closed, individuals <20 under home confinementVery strict lockdownSleep quality
Werling et al, 2021, Switzerland97Cross-sectionalPatients referred for attention deficit hyperactivity disorder aged 10 to 18 years126Not reported25.4%March 16, 2020: complete lockdown resulting in school closure and homeschooling; first easing of restrictions starting from April 26 with first schools reopened on May 11 and most students returned to classes in June 2020, at least part-timeModerate lockdownScreen time
Werling et al, 2021, Switzerland98Cross-sectionalChildren and adolescents with psychiatric disorders aged 10 to 18 years47713.96 years (2.29)41.9%March 16, 2020: complete lockdown resulting in school closure and homeschooling; schools gradually reopened after May 11, 2020, but many students did not return to onsite class before the second week of June, often with reduced onsite hours, and in some cases, not at all before the summer vacationModerate lockdownScreen time
Yang et al, 2020, China66Cross-sectionalHigh school students (sub-group)2824 (High school students)17.50 years (1.20)76.0%COVID-19 lockdown from 24 January to 23 FebruaryUnclearPhysical activity, screen time, sleep duration
Zenic et al, 2020, Croatia60Cohort (Prospective)Adolescents attending high school82316.50 years (2.10)Not reportedSchools closed; extensive social distancing measures implemented, including a ban on public gatherings and closure of nonessential services such as restaurants, shopping centres, sports and recreational facilities, and places of worshipStrict lockdownPhysical activity
Zengin et al, 2021, Turkey61Cross-sectionalChildren aged 9 to 12 years attending primary schools30910.30 years (1.20)47.9%Complete closure of schools (distance learning) and a partial or full-time curfew for children under the age of 20Very strict lockdownPhysical activity, sleep duration and quality
  • ADHD, Attention deficit hyperactivity disorder; ASD, Autism spectrum disorder.