Effects of physical activity and use of digital devices on visual acuity in children and adolescents during the COVID-19 pandemic: A cross-sectional study.

Purpose: To determine the association between poor visual acuity, the use of digital devices and physical activity (PA) during the COVID-19 pandemic. Methods: A total of 327,646 Chinese children and adolescents were included in the analysis using a cluster random sampling method; this is a case-control study, of those 144,708 children and adolescents with poor visual acuity were included in the case group, while 182,938 who did not have poor visual acuity were included in the control group. A logistic regression model was used to assess the contribution of PA and the use of digital devices to poor visual acuity. Results: A total of 144,708 children and adolescents experienced poor visual acuity during the COVID-19 pandemic; 54.8% were male, and 55.2% live in rural areas. Compared to controls, children and adolescents with poor visual acuity exhibited more time for the use of digital devices (4.51 ± 2.44 vs. 3.79 ± 2.34 for cases and controls, respectively; P < 0.001) and PA (3.07 ± 0.92 vs. 2.85 ± 1.00 for cases and controls, respectively; P < 0.001). During the COVID-19 pandemic, risk factors related to poor visual acuity among children and adolescents included the use of digital devices (OR 1.135; 95% CI 1.132-1.139), and PA (OR 1.269; 95%CI 1.259-1.278). The results of interaction analysis show that for children and adolescents aged 12 to 17, the positive association between the use of digital devices and poor visual acuity decreased. The interaction effect between PA and digital devices is 0.987. Conclusions: Children and adolescents were at risk of poor visual acuity during the COVID-19 pandemic. Extended use of the digital devices increased the risk of poor visual acuity, especially for children aged 6-11 years. But the risk of poor visual acuity among children and adolescents decreases as the time spent on PA increases.

Prevalence and Risk Factors Associated With Self-reported Psychological Distress Among Children and Adolescents During the COVID-19 Pandemic in China.

Importance: Schools have been suspended nationwide in 188 countries, and classes have shifted to home-based distance learning models to control the spread of the coronavirus disease 2019 (COVID-19) pandemic. Additional information is needed to determine mental health status among school-aged children and adolescents during this public health crisis and the risk factors associated with psychological distress during the pandemic. Objective: To assess self-reported psychological distress among school-aged children and adolescents associated with the COVID-19 pandemic. Design, Setting, and Participants: This cross-sectional study using data from a survey on the mental health of school-aged children and adolescents in Guangdong province, China, conducted by using a stratified cluster random sampling method between March 8 to 30, 2020. To estimate outcomes associated with location of districts, only data from students with internet protocol addresses and current addresses in Guangdong were included. Data were analyzed from April 5 to July 20, 2020. Exposure: Home-based distance learning during the COVID-19 pandemic. Main Outcome and Measures: The main outcome was self-reported psychological distress, measured using the total score on the 12-item General Health Questionnaire of 3 or greater. Multivariate logistic regression was used to analyze risk factors associated with mental health status. Odds ratios (ORs) were used to analyze the associations of factors with psychological distress. Results: Among 1 310 600 students who completed the survey, 1 199 320 students (mean [SD] age, 12.04 [3.01] years; 619 144 [51.6%] boys) were included in the final analysis. A total of 126 355 students (10.5%) self-reported psychological distress. Compared with students in primary school, high school students had increased risk of psychological distress (OR, 1.19 [95% CI, 1.15-1.23]). Compared with students who wore a face mask frequently, students who never wore a face mask had increased risk of psychological distress (OR, 2.59 [95% CI, 2.41-2.79]). Additionally, students who spent less than 0.5 hours exercising had increased odds of self-reported psychological distress compared with students who spent more than 1 hour exercising (OR, 1.64 [95% CI, 1.61-1.67]). Conclusions and Relevance: These findings suggest that the prevalence of self-reported psychological distress among students during the COVID-19 pandemic was relatively high. Frequency of wearing a face mask and time spent exercising were factors associated with mental health. Therefore, it may be necessary for governments, schools, and families to pay attention to the mental health of school-aged children and adolescents during the COVID-19 pandemic and take corresponding countermeasures to reduce the impact of the COVID-19 pandemic on students' mental health.