Public health preventive measures and child health behaviours during COVID-19: a cohort study
Authors: Li Xuedi , Vanderloo Leigh M. , Maguire Jonathon L. , Keown-Stoneman Charles D. G. , Aglipay Mary , Anderson Laura N. , Cost Katherine Tombeau , Charach Alice , Vanderhout Shelley M. , Birken Catherine S. ,   TARGet Kids! Collaboration, Birken Catherine S. , Maguire Jonathon L. , Cohn Ronald , Lau Eddy , Laupacis Andreas , Parkin Patricia C. , Salter Michael , Weir-Seeley Shannon , Anderson Laura N. , Borkhoff Cornelia M. , Keown-Stoneman Charles , Kowal Christine , Mason Dalah , Abdurrahman Murtala , Anderson Kelly , Arbess Gordon , Baker Jillian , Barozzino Tony , Bergeron Sylvie , Bloch Gary , Bonifacio Joey , Bowry Ashna , Calpin Caroline , Campbell Douglas , Cheema Sohail , Cheng Elaine , Chisamore Brian , Constantin Evelyn , Danayan Karoon , Das Paul , Derocher Mary Beth , Do Anh , Doukas Kathleen , Egger Anne , Farber Allison , Freedman Amy , Freeman Sloane , Gazeley Sharon , Guiang Charlie , Ha Dan , Handford Curtis , Hanson Laura , Harrington Leah , Jacobson Sheila , Jagiello Lukasz , Jansz Gwen , Kadar Paul , Kiran Tara , Knowles Holly , Kwok Bruce , Lakhoo Sheila , Lam-Antoniades Margarita , Lau Eddy , Leduc Denis , Leung Fok-Han , Li Alan , Li Patricia , Malach Jessica , Male Roy , Meret Aleks , Mok Elise , Moodie Rosemary , Nash Katherine , Naymark Sharon , Owen James , Peer Michael , Perlmutar Marty , Persaud Navindra , Pinto Andrew , Porepa Michelle , Qi Vikky , Ramji Noor , Raza Danyaal , Rosenthal Alana , Rouleau Katherine , Ruderman Caroline , Saunderson Janet , Schiralli Vanna , Sgro Michael , Shuja Hafiz , Shepherd Susan , Smiltnieks Barbara , Srikanthan Cinntha , Taylor Carolyn , Treherne Stephen , Turner Suzanne , Uddin Fatima , van den Heuvel Meta , Weisdorf Thea , Wong Peter , Yaremko John , Ying Ethel , Young Elizabeth , Zajdman Michael , Bustos Marivic , Flores Pamela Ruth , Jaleel Mateenah , Malhi Tarandeep , Malick Ataat , Mitchell Michelle , Ogwuru Martin , Ong Frank , Rajendran Rejina , Thadani Sharon , Thompson Julia , Thompson Laurie , Aglipay Mary , Bayoumi Imaan , Carsley Sarah , Cost Katherine , Eny Karen , Kinlin Laura , Omand Jessica , Vanderhout Shelley , Vanderloo Leigh , Allen Christopher , Boodhoo Bryan , Juni Peter , Lakhanpal Gurpreet , Lebovic Gerald , Stitt Audra , Kandel Rita , Rodrigues Michelle 
Published: July 2021

Abstract
Objective
The primary objective was to determine the association between public health preventive measures and children’s outdoor time, sleep duration, and screen time during COVID-19.

Methods
A cohort study using repeated measures of exposures and outcomes was conducted in healthy children (0 to 10 years) through The Applied Research Group for Kids (TARGet Kids!) COVID-19 Study of Children and Families in Toronto, Canada, between April 14 and July 15, 2020. Parents were asked to complete questionnaires about adherence to public health measures and children’s health behaviours. The primary exposure was the average number of days that children practiced public health preventive measures per week. The three outcomes were children’s outdoor time, total screen time, and sleep duration during COVID-19. Linear mixed-effects models were fitted using repeated measures of primary exposure and outcomes.

Results
This study included 554 observations from 265 children. The mean age of participants was 5.5 years, 47.5% were female and 71.6% had mothers of European ethnicity. Public health preventive measures were associated with shorter outdoor time (−17.2; 95% CI −22.07, −12.40; p < 0.001) and longer total screen time (11.3; 95% CI 3.88, 18.79; p = 0.003) during COVID-19. The association with outdoor time was stronger in younger children (<5 years), and the associations with total screen time were stronger in females and in older children (≥5 years).

Conclusion
Public health preventive measures during COVID-19 were associated with a negative impact on the health behaviours of Canadian children living in a large metropolitan area.