RESUMEN
Background: The outbreak of coronavirus disease in 2019 (COVID-19) has had an enormous impact on people’s health, and profoundly changed our lives and society. However, the impact of pandemic-related home confinement on children’s life and their mental health remains unknown. We took advantage of a natural experiment due to the onset of COVID-19 and examined this issue in two consecutive cohorts. Methods: This study compared mental health, family environment and lifestyles of two representative cohorts of young children in Shanghai, China. Both prospective cohorts recruited children at entry to kindergarten. Surveys were conducted at both entry and graduation of kindergarten using the same assessment instruments. Children in the non-exposed cohort experienced a normal period of kindergarten study and graduated in June, 2019; those in the exposed cohort were under confinement for five months and graduated in June, 2020. Findings: Compared with the non-exposed cohort, the exposed cohort had a significant increased percentage of children classified as “at-risk for mental health problems”, with an adjusted absolute risk difference of 3·1% (95% CI, 1·9% to 4·4%) for total difficulties as measured by the Strength and Difficulty Questionnaire. The effect of pandemic related confinement on mental health was larger in children with lower parental education. The exposed cohort had longer media time, sleep duration and a less favorable home environment. Interpretation: The pandemic related confinement negatively affected children's mental health and home environment. Strategies and actions are urgently needed to improve parenting skills and mitigate the negative impact by strengthening the family environment.Funding Statement: National Natural Science Foundation of China, Shanghai Committee of Science and Technology, Shanghai Municipal Health Commission, Shanghai Education CommitteeDeclaration of Interests: We declare no competing interests.Ethics Approval Statement: The study was approved by the Institutional Review Board of the Shanghai Children’s Medical Center, the Shanghai Jiao Tong University School of Medicine (SCMCIRB-K2016022-01)