Association Between Screen Time Trajectory and Early Childhood Development in Children in China

Screen Media Use and Mental Health of Children and Adolescents: A Secondary Analysis of a Randomized Clinical Trial

Importance

Excessive screen media use has been associated with poorer mental health among children and adolescents in several observational studies. However, experimental evidence supporting this hypothesis is lacking.

Objective

To investigate the effects of a 2-week screen media reduction intervention on children's and adolescents' mental health.

Design, Setting, and Participants

This prespecified secondary analysis of a cluster randomized clinical trial with a 2-week follow-up included 89 families (with 181 children and adolescents) from 10 Danish municipalities in the region of Southern Denmark. All study procedures were carried out in the home of the participants. Enrollment began on June 6, 2019, and ended on March 30, 2021. This analysis was conducted between January 1 and November 30, 2023.

Intervention

Families were randomly allocated to a screen media reduction group or a control group. The 2-week screen media reduction intervention was designed to ensure a high level of compliance to the reduction in leisure-time screen media use. Participants allocated to the intervention group had to reduce their leisure-time screen media use to 3 hours per week or less per person and hand over smartphones and tablets.

Main Outcomes and Measures

The main outcome was the between-group mean difference in change in total behavioral difficulties, measured by the Strengths and Difficulties Questionnaire at 2-week follow-up. Results were estimated using mixed-effects tobit regression models. Analyses were carried out as both intention to treat and complete case.

Results

In the sample of 89 families including 181 children and adolescents (intervention group [45 families]: 86 children; mean [SD] age, 8.6 [2.7] years; 42 girls [49%]; control group [44 families]: 95 children; mean [SD] age, 9.5 [2.5] years; 57 girls [60%]), there was a statistically significant between-group mean difference in the total difficulties score, favoring the screen media reduction intervention (-1.67; 95% CI, -2.68 to -0.67; Cohen d, 0.53). The greatest improvements were observed for internalizing symptoms (emotional symptoms and peer problems; between-group mean difference, -1.03; 95% CI, -1.76 to -0.29) and prosocial behavior (between-group mean difference, 0.84; 95% CI, 0.39-1.30).

Conclusions and Relevance

This secondary analysis of a randomized clinical trial found that a short-term reduction in leisure-time screen media use within families positively affected psychological symptoms of children and adolescents, particularly by mitigating internalizing behavioral issues and enhancing prosocial behavior. More research is needed to confirm whether these effects are sustainable in the long term.

Trial Registration

ClinicalTrials.gov Identifier: NCT04098913.

The importance of mother-child interaction on smart device usage and behavior outcomes among toddlers: a longitudinal study

BACKGROUND

In recent years, smart devices have become an integral part of daily life. However, longitudinal studies, particularly those regarding the relationship between toddlers' smart device usage and behavioral outcomes, are limited. Understanding the impact of parent-child interactions on this relationship is crucial for enhancing toddlers' developmental outcomes. Accordingly, this study examined the influence of early screen time and media content exposure on toddlers' behaviors, as well as the positive effects of mother-child interactions on this influence.

METHODS

We used relevant data related to 277 children born between November 2016 and July 2020 and who were part of an ongoing prospective follow-up study conducted across five hospitals in Taipei City, Taiwan. We analyzed (1) data from maternal reports regarding children's behavior by using the Child Behavior Checklist (for ages 11/2-5 years), (2) assessments of mother-child interactions by using the Brigance Parent-Child Interactions Scale, and (3) self-reported parental data covering the first 3 postpartum years. Statistical analyses involved group-based trajectory modeling and multiple linear regression.

RESULTS

A considerable increase in screen time between the ages of 1 and 3 years was associated with less favorable behavioral outcomes at age 3. These outcomes included somatic complaints [adjusted beta coefficient (aβ) = 2.17, 95% confidence interval (CI) = 0.39-3.95, p-value = 0.01], withdrawal (aβ = 2.42, 95% CI = 0.15-4.69, p-value = 0.04), and aggressive behavior (aβ = 6.53, 95% CI = 0.25-12.81, p-value = 0.04). This association was particularly evident among children with lower levels of mother-child interaction. Nevertheless, positive mother-child interactions mitigated most of the adverse effects. Additionally, increased exposure to games and cartoons was associated with poorer behavioral outcomes in all children except for those experiencing positive mother-child interactions.

CONCLUSION

Early mother-child interactions play a crucial role in mitigating the risk of behavioral problems in toddlers who spend prolonged periods looking at screens and who are frequently exposed to game and cartoon content.

A study of the effects of screen exposure on the neuropsychological development in children with autism spectrum disorders based on ScreenQ

PURPOSE

To investigate the relationship between multi-dimensional aspects of screen exposure and autistic symptoms, as well as neuropsychological development in children with ASD.

METHODS

We compared the ScreenQ and Griffiths Development Scales-Chinese Language Edition (GDS-C) of 636 ASD children (40.79 ± 11.45 months) and 43 typically developing (TD) children (42.44 ± 9.61 months). Then, we analyzed the correlations between ScreenQ and Childhood Autism Rating Scale (CARS), and GDS-C. We further used linear regression model to analyze the risk factors associated with high CARS total scores and low development quotients (DQs) in children with ASD.

RESULTS

The CARS of children with ASD was positively correlated with the ScreenQ total scores and "access, frequency, co-viewing" items of ScreenQ. The personal social skills DQ was negatively correlated with the "access, frequency, content, co-viewing and total scores" of ScreenQ. The hearing-speech DQ was negatively correlated with the "frequency, content, co-viewing and total scores" of ScreenQ. The eye-hand coordination DQ was negatively correlated with the "frequency and total scores" of ScreenQ. The performance DQ was negatively correlated with the "frequency" item of ScreenQ.

CONCLUSION

ScreenQ can be used in the study of screen exposure in children with ASD. The higher the ScreenQ scores, the more severe the autistic symptoms tend to be, and the more delayed the development of children with ASD in the domains of personal-social, hearing-speech and eye-hand coordination. In addition, "frequency" has the greatest impact on the domains of personal social skills, hearing-speech, eye-hand coordination and performance of children with ASD.

Association between urinary BTEX metabolites and dyslexic odds among school-aged children

Benzene, toluene, ethylbenzene, and xylene (BTEX) are ubiquitous in the environment, and all of them can cause neurotoxicity. However, the association between BTEX exposure and dyslexia, a disorder with language network-related regions in left hemisphere affected, remains unclear. We aimed to assess the relationship between BTEX exposure and dyslexic odds among school-aged children. A case-control study, including 355 dyslexics and 390 controls from three cities in China, was conducted. Six BTEX metabolites were measured in their urine samples. Logistic regression model was used to explore the association between the BTEX metabolites and the dyslexic odds. Urinary trans,trans-muconic acid (MU: a metabolite of benzene) was significantly associated with an increased dyslexic odds [odds ratio (OR) = 1.23, 95% confidence interval (CI): 1.01, 1.50], and the adjusted OR of the dyslexic odds in the third tertile was 1.72 (95% CI: 1.06, 2.77) compared to that in the lowest tertile regarding urinary MU concentration. Furthermore, the association between urinary MU level and the dyslexic odds was more pronounced among children from low-income families based on stratified analyses. Urinary metabolite levels of toluene, ethylbenzene, and xylene were not found to be associated with the dyslexic odds. In summary, elevated MU concentrations may be associated with an increased dyslexic odds. We should take measures to reduce MU related exposure among children, particularly those with low family income.

Screen Time and Socioemotional and Behavioural Difficulties Among Indigenous Children in Canada: Temps d'écran et difficultés socio-émotionnelles et comportementales chez les enfants autochtones du Canada

OBJECTIVES

To describe screen time levels and determine their association with socioemotional and behavioural difficulties among preschool-aged First Nations, Métis, and Inuit children.

METHOD

Data were taken from the Aboriginal Children's Survey, a nationally representative survey of 2-5-year-old Indigenous children in Canada. Socioemotional and behavioural difficulties were defined using parent/guardian reports on the Strengths and Difficulties Questionnaire. Multiple linear regression analyses were conducted separately for First Nations, Métis, and Inuit participants, and statistically adjusted for child age, child sex, and parent/guardian education. Statistical significance was set at P < 0.002 to adjust for multiple comparisons.

RESULTS

Of these 2-5-year-old children (mean [M] = 3.57 years) 3,085 were First Nations (53.5%), 2,430 Métis (39.2%), and 990 Inuit (7.3%). Screen time exposure was high among First Nations (M = 2 h and 58 min/day, standard deviation [SD] = 1.89), Métis (M = 2 h and 50 min [SD = 1.83]), and Inuit children (M = 3 h and 25 min [SD = 2.20]), with 79.7% exceeding recommended guidelines (>1 h/day). After adjusting for confounders, screen time was associated with more socioemotional and behavioural difficulties among First Nations (total difficulties β = 0.15 [95% CI, 0.12 to 0.19]) and Métis (β = 0.16 [95% CI, 0.12 to 0.20]) but not Inuit children (β = 0.12 [95% CI, 0.01 to 0.23]).

CONCLUSIONS

Screen time exposure is high among Indigenous children in Canada, and is associated with more socioemotional and behavioural difficulties among First Nations and Métis children. Contributing factors could include enduring colonialism that resulted in family dissolution, lack of positive parental role models, and disproportionate socioeconomic disadvantage. Predictors of poor well-being should continue to be identified to develop targets for intervention to optimize the health and development of Indigenous children.

Types of On-Screen Content and Mental Health in Kindergarten Children

Importance

Excessive screen time has been associated with a higher risk for mental health problems, but whether the associations differ by screen content types is unclear.

Objective

To examine the allocation of and longitudinal changes in screen exposure across different content types and to explore their associations with mental health in children aged 3 to 6 years.

Design, Setting, and Participants

This cohort study used 3-wave, lagged generalized estimating equation models to analyze data from the Shanghai Children's Health, Education and Lifestyle Evaluation-Preschool (SCHEDULE-P) study in Shanghai, China. The cohort was a representative sample of kindergarten children. Data were collected between November 2016 and May 2019 when children were aged 3 to 4 years (wave 1), 4 to 5 years (wave 2), and 5 to 6 years (wave 3). Data analysis was performed between June 2022 and May 2023.

Exposure

Screen exposure (total daily time and time with each type of content, including educational programs, entertainment programs, non-child-directed programs, electronic games, and social media) was collected when children were aged 3, 5, and 6 years.

Main Outcomes and Measures

Mental health of children at age 3, 5, and 6 years was reported by parents using the Strengths and Difficulties Questionnaire.

Results

Of the 15 965 children included in the representative sample, 8270 were males (51.7%) and the mean (SD) age at wave 1 was 3.73 (0.30) years. As children developed from ages 3 to 6 years, the proportion of screen exposure to educational programs (≤1 hour per day: 45.0% [95% CI, 43.5%-46.5%] to 26.8% [95% CI, 25.3%-28.3%]) and entertainment programs (≤1 hour per day: 44.4% [95% CI, 42.8%-45.9%] to 32.1% [95% CI, 30.4%-33.9%]) decreased, whereas exposure to social media increased (≤1 hour per day: 1.5% [95% CI, 1.2%-1.9%] to 27.1% [95% CI, 25.5%-28.7%]). The associations between on-screen content and mental health varied. For a given total screen time, a higher proportion of screen exposure to educational programs was associated with a lower risk for mental health problems (adjusted odds ratio [AOR], 0.73; 95% CI, 0.60-0.90), whereas non-child-directed programs were associated with a higher risk for such problems (AOR, 2.82; 95% CI, 1.91-4.18). Regardless of the content, total screen time was consistently associated with mental health problems.

Conclusions and relevance

Results of this study indicated that both total screen time and different types of content were associated with mental health problems in children aged 3 to 6 years. Limiting children's screen time, prioritizing educational programs, and avoiding non-child-directed programs are recommended.

Family Meal Environment Differentially Conditions the Prospective Association between Early Childhood Screen Time and Key Social Relationships in Adolescent Girls

Background: Despite screen time recommendations, children are increasingly spending time on electronic devices, rendering it an important risk factor for subsequent social and developmental outcomes. Sharing meals could offer a way to promote psychosocial development. This study examines the interaction between family meal environment and early childhood screen time on key adolescent social relationships. Methods: Participants are 1455 millennial children (49% boys) from the Quebec Longitudinal Study of Child Development birth cohort. Parents reported on child screen use at ages 2 and 6 years and family meal environment quality at age 6 years. Parents and children reported on parent-child relationships and peer victimization experiences, respectively, at age 13 years. Sex-stratified multiple regression estimated the direct association between screen time trends, family meal environment quality, and their interaction on later social relationship outcomes. Results: For girls, when preschool screen time increased, sharing family meals in high-quality environments was associated with more positive and less conflictual relationships with their mothers, whereas meals shared in low- and moderate-quality environments were associated with fewer instances of victimization by their peers. Non-linear associations were not significant for boys. Conclusion: Capitalizing on family meal environment represents a simple/cost-efficient activity that can compensate for some long-term risks associated with increased screen use, above and beyond pre-existing and concurrent individual and family characteristics. Public health initiatives may benefit from considering family meals as a complementary intervention strategy to screen use guidelines.

Change in screen time and overuse, and their association with psychological well-being among US-wide school-age children during the COVID-19 pandemic: analysis of the National Survey of Children's Health (NSCH) years 2018-21

BACKGROUND

Previous studies on screen use and children's mental health during the Coronavirus Disease 2019 (COVID-19) pandemic focused only on the timeframe during the pandemic, on children between narrow age ranges, only among a subset of children who have previously reported COVID-related severe family economic hardship or worries, or did not distinguish between instructive versus recreational device usage. Thus, in this study, we analyzed trends, specifically related to recreational screen use, and associations with psychological well-being (PWB) in the years before versus during the COVID-19 pandemic, among a wide range of school-aged children, widely across the nation.

METHODS

Using the National Survey of Children's Health (NSCH) years 2018-21, we analyzed a large random sample of school-aged children (6-17 years old) across the US (n = 88,823). We developed PWB issue scores (PWBIS) using self-reported measures relevant to this age group, and constructed regression models to assess the magnitude of the contribution of the pandemic on recreational screen use and PWB.

RESULTS

The prevalence of recreational screen overuse and PWBIS increased significantly during the pandemic, compared to prior years. We also detected a notable effect of the pandemic on increased PWBIS, as well as its interaction term finding that it strengthened the association between screen time and PWBIS (p < 0.01 across all regression models).

CONCLUSIONS

Accordingly, our results demonstrate the importance of the pandemic itself as an independent adverse factor and effect measure modifier for screen overuse and PWB more generally among all school-age children widely across the US. Our study used the most current data available, and future studies to evaluate whether these effects are persistent in the years after the pandemic are important.

Associations between maternal exposure to air pollution during pregnancy and trajectories of infant growth: A birth cohort study

OBJECTIVE

We examined the relationships between infants' growth trajectories and prenatal exposure to air pollution, which is still under-investigated.

METHODS

A birth cohort study was constructed using medical records of pregnant women and infants born between 2015 and 2019 in Foshan, China. Using satellite-based spatial-temporal models, prenatal exposure to air pollutants including particulate matter with an aerodynamic dimension of < 2.5 µm (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) was assessed at each woman's residence. Latent class growth modeling was used to identify trajectories of physical (body length and weight) growth and neurodevelopment, which were repeatedly measured within 1 year after birth. Logistic regression models were used to investigate the associations between prenatal exposure to air pollution and the risks of growth disorders, adjusting for an array of potential confounders.

RESULTS

We identified two growth trajectories for body length [normal: 3829 (93%); retardation: 288 (7%)], three for weight [normal: 2475 (59.6%); retardation: 390 (9.4%); overgrowth: 1287 (31%)], and two for neurodevelopment [normal: 956 (66.1%); retardation: 491 (33.9%)]. For exposure over whole pregnancy, SO2 was associated with an increased risk of body length retardation (OR for per 1 µg/m3 increment: 1.09, 95%CI: 1.01-1.17); PM2.5 (OR: 1.05, 95%CI: 1.03-1.07), SO2 (OR: 1.15, 95%CI: 1.08-1.22), and NO2 (OR: 1.05, 95%CI: 1.03-1.07) were positively associated with neurodevelopmental retardation. Such associations appeared stronger for exposures over the first and second trimesters. No significant associations were detected for weight growth.

CONCLUSIONS

Maternal exposure to air pollution during pregnancy was associated with higher risks of impairments in both physical growth, particularly body length, and neurodevelopment.

Early-initiated childhood reading for pleasure: associations with better cognitive performance, mental well-being and brain structure in young adolescence

BACKGROUND

Childhood is a crucial neurodevelopmental period. We investigated whether childhood reading for pleasure (RfP) was related to young adolescent assessments of cognition, mental health, and brain structure.

METHODS

We conducted a cross-sectional and longitudinal study in a large-scale US national cohort (10 000 + young adolescents), using the well-established linear mixed model and structural equation methods for twin study, longitudinal and mediation analyses. A 2-sample Mendelian randomization (MR) analysis for potential causal inference was also performed. Important factors including socio-economic status were controlled.

RESULTS

Early-initiated long-standing childhood RfP (early RfP) was highly positively correlated with performance on cognitive tests and significantly negatively correlated with mental health problem scores of young adolescents. These participants with higher early RfP scores exhibited moderately larger total brain cortical areas and volumes, with increased regions including the temporal, frontal, insula, supramarginal; left angular, para-hippocampal; right middle-occipital, anterior-cingulate, orbital areas; and subcortical ventral-diencephalon and thalamus. These brain structures were significantly related to their cognitive and mental health scores, and displayed significant mediation effects. Early RfP was longitudinally associated with higher crystallized cognition and lower attention symptoms at follow-up. Approximately 12 h/week of youth regular RfP was cognitively optimal. We further observed a moderately significant heritability of early RfP, with considerable contribution from environments. MR analysis revealed beneficial causal associations of early RfP with adult cognitive performance and left superior temporal structure.

CONCLUSIONS

These findings, for the first time, revealed the important relationships of early RfP with subsequent brain and cognitive development and mental well-being.

Cross-sectional and prospective associations between screen time and childhood neurodevelopment in two Brazilian cohorts born 11 years apart

BACKGROUND

The aim of this study was to investigate the associations between screen time from ages 2 to 4 years and child neurodevelopment at age 4.

METHODS

The participants were from the 2004 (N = 3787) and 2015 (N = 3604) Pelotas (Brazil) birth cohort studies. Childhood neurodevelopment was assessed at age 4 using the Battelle Development Inventory. The time children spent on screen devices was reported by their guardians at ages 2 and 4 years. Linear regression models were used to investigate the association of: (i) time spent on television at ages 2 and 4 years; (ii) time spent on other screens at age 4; and (iii) total screen time at age 4 (television + other screens) with childhood neurodevelopment at age 4.

RESULTS

Average daily screen time among children born in 2004 and those born in 2005 aged 4 years were 3.4 (SD: 2.4) and 4.4 h (SD: 2.9), respectively. Overall, few associations of very small magnitude between screen time and child neurodevelopment were observed. Television time at 2 years of age was statistically associated with lower neurodevelopment at 4 years of age in the 2015 cohort (β = -0.30, 95%CI = -0.55; -0.05). Conversely, television time (β = 0.17, 95%CI = 0.07, 0.26) and total screen time (β = 0.22, 95%CI = 0.13, 0.31) at age 4 were associated with higher neurodevelopment at age 4 in the 2004 cohort.

CONCLUSIONS

The findings of this study suggest that the amount of time spent on screen devices might not be associated with neurodevelopment of children under 5 years of age. The small magnitude and inconsistencies in the direction of associations did not find evidence to support the current guidelines for screen time at this age. Therefore, more studies, especially those with longitudinal data, are important to comprehend the true effect of screen time on neurodevelopment and other health outcomes.

Trajectories of spherical equivalent refraction from grades 1 to 4 in Chinese children

BACKGROUND

The development trajectories of children's SER remain unknown. This study aimed to characterize spherical equivalent refraction (SER) trajectories during grades 1-4 in Chinese children.

METHODS

This prospective cohort study included 1226 first-grade non-myopic children from 12 public primary schools, randomly selected in two districts in Guangzhou, China. From November 2018 to March 2022, four-wave ocular examinations and questionnaire surveys have been completed. The group-based trajectory modeling was used to explore SER trajectories in grades 1-4.

RESULTS

All five trajectories showed an upward trend and rose faster after grade 2. Children in the sharp-developing (n = 44), high-developing (n = 136), and rapid-developing (n = 237) myopia groups developed myopia before grades 2, 3, and 4, respectively. Their SER development speed remained at a relatively high level after myopia, almost consistent with that before myopia. Children in the moderate-developing (n = 418) and low-developing (n = 391) non-myopia groups did not develop myopia before grade 4. Some characteristics in grade 1 were independently associated with SER trajectories, including sex, axial length, number of parents with myopia, residence, academic achievement, and the duration of outdoor activity. Based on the baseline characteristics, we established the model predicting the probability of children belonging to each group.

CONCLUSIONS

Myopia interventions are best started in grade 1 or preschool age. If interventions are not taken in time, the latest intervention window might be in grades 1, 2, and 3 for children with a high probability of belonging to the sharp-developing, high-developing, and rapid-developing myopia groups, respectively. The above probabilities might be predicted using the model we established. Moreover, the interventions for myopic children shouldn't be ignored.

Screen Time and Developmental Performance Among Children at 1-3 Years of Age in the Japan Environment and Children's Study

Importance

It is unclear whether increased television (TV) and DVD viewing in early childhood from age 1 year decreases development or whether poor development increases TV/DVD viewing.

Objective

To investigate the directional association between TV/DVD screen time and performance on developmental screeners in children aged 1 to 3 years.

Design, Setting, and Participants

This longitudinal cohort study analyzed data from 57 980 children and mothers from a national birth cohort, the Japan Environment and Children's Study. Data were collected in collaboration with 15 regional centers across Japan. The mothers were recruited between January 2011 and March 2014. Analyses using random intercept, cross-lagged panel models were performed for children aged 1, 2, and 3 years. Of 100 303 live births, children with missing developmental screening test scores and screen time data, those with congenital diseases or cerebral palsy, and those diagnosed with an autism spectrum disorder were excluded. Statistical analyses were conducted from October 2022 to July 2023.

Exposures

TV and DVD screen time.

Main Outcomes and Measures

Child development at ages 1, 2, and 3 years was assessed via the mother's or guardian's report using the Ages and Stages Questionnaire, third edition.

Results

Of 57 980 included children, 29 418 (50.7%) were male, and the mean (SD) maternal age at delivery was 31.5 (4.9) years. A negative association between screen time and developmental scores was observed. Increased TV/DVD screen times at age 1 and 2 years were associated with lower developmental scores at age 2 and 3 years, respectively (2 years: β = -0.05; 95% CI, -0.06 to -0.04; 3 years: β = -0.08; 95% CI, -0.09 to -0.06). An obverse association was observed from the Ages and Stages Questionnaires, third edition, score in the communication domain at age 1 and 2 years to subsequent screen time (2 years: γ = -0.03; 95% CI, -0.04 to -0.02; 3 years: γ = -0.06; 95% CI, -0.07 to -0.04).

Conclusions and Relevance

In this study, increased TV/DVD screen time from age 1 year negatively affected later development. To reduce the negative consequences of excessive media use, researchers and health care professionals should encourage family media management and recommend social support for parents who tend to rely on the media.

Screen Time at Age 1 Year and Communication and Problem-Solving Developmental Delay at 2 and 4 Years

Importance

Whether some domains of child development are specifically associated with screen time and whether the association continues with age remain unknown.

Objective

To examine the association between screen time exposure among children aged 1 year and 5 domains of developmental delay (communication, gross motor, fine motor, problem-solving, and personal and social skills) at age 2 and 4 years.

Design, Participants, and Setting

This cohort study was conducted under the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Pregnant women at 50 obstetric clinics and hospitals in the Miyagi and Iwate prefectures in Japan were recruited into the study between July 2013 and March 2017. The information was collected prospectively, and 7097 mother-child pairs were included in the analysis. Data analysis was performed on March 20, 2023.

Exposure

Four categories of screen time exposure were identified for children aged 1 year (<1, 1 to <2, 2 to <4, or ≥4 h/d).

Main Outcomes and Measures

Developmental delays in the 5 domains for children aged 2 and 4 years were assessed using the Japanese version of the Ages & Stages Questionnaires, Third Edition. Each domain ranged from 0 to 60 points. Developmental delay was defined if the total score for each domain was less than 2 SDs from its mean score.

Results

Of the 7097 children in this study, 3674 were boys (51.8%) and 3423 were girls (48.2%). With regard to screen time exposure per day, 3440 children (48.5%) had less than 1 hour, 2095 (29.5%) had 1 to less than 2 hours, 1272 (17.9%) had 2 to less than 4 hours, and 290 (4.1%) had 4 or more hours. Children's screen time was associated with a higher risk of developmental delay at age 2 years in the communication (odds ratio [OR], 1.61 [95% CI, 1.23-2.10] for 1 to <2 h/d; 2.04 [1.52-2.74] for 2 to <4 h/d; 4.78 [3.24-7.06] for ≥4 vs <1 h/d), fine motor (1.74 [1.09-2.79] for ≥4 vs <1 h/d), problem-solving (1.40 [1.02-1.92] for 2 to <4 h/d; 2.67 [1.72-4.14] for ≥4 vs <1 h/d), and personal and social skills (2.10 [1.39-3.18] for ≥4 vs <1 h/d) domains. Regarding risk of developmental delay at age 4 years, associations were identified in the communication (OR, 1.64 [95% CI, 1.20-2.25] for 2 to <4 h/d; 2.68 [1.68-4.27] for ≥4 vs <1 h/d) and problem-solving (1.91 [1.17-3.14] for ≥4 vs <1 h/d) domains.

Conclusions and Relevance

In this study, greater screen time for children aged 1 year was associated with developmental delays in communication and problem-solving at ages 2 and 4 years. These findings suggest that domains of developmental delay should be considered separately in future discussions on screen time and child development.

Qualitative study of the association between psychosocial health and physical activity/sleep quality in toddlers

Physical activity and sleep are important factors of mental and physical health in children, with some reports indicating that their effects can persist into adulthood. However, there is limited research on the qualitative aspects of physical activity and sleep in preschool children, particularly in those aged < 3 years. Therefore, to elucidate the association between psychosocial health and physical activity/sleep in early childhood in terms of qualitative aspects, we conducted a retrospective cohort study in 2985 3-year-old children (37.2 ± 0.75 months) in Shanghai, China. An analysis using structural equation modeling indicated that current physical activity had a direct and moderate impact on current psychosocial health evaluated using the Strength and Difficulties Questionnaire. In particular, past physical activity had an indirect and mild effect on current psychosocial health via current physical activity in girls. However, regardless of sex, past sleep quality had slight impact on current psychosocial health, not only indirectly via current sleep quality, but also directly. These findings highlight the importance of considering the qualitative aspects of physical activity and sleep quality as significant factors influencing the current and future psychosocial health of children, even at a very early age (< 3 years).

Shyness and Socio-Emotional Adjustment among Young Chinese Children: The Moderating Role of Screen Time

The primary aim of the present study was to examine the potential moderating role of screen time in the links between shyness and indices of socio-emotional adjustment in young Chinese children. Participants were N = 211 children (112 boys, 99 girls) ages 43-66 months (M = 58.84 months, SD = 5.32) recruited from two public kindergartens in Shanghai, People's Republic of China. Mothers completed assessments of children's shyness and screen time, and both mothers and teachers completed measures of indices of children's socio-emotional functioning (prosocial, internalizing problems, learning problems). Among the results, shyness was positively associated with internalizing problems and negatively associated with prosocial behavior, whereas screen time was positively associated with internalizing problems. However, several significant shyness × screen time interaction effects were observed. The pattern of these results consistently revealed that at higher levels of screen time, links between shyness and indices of socio-emotional difficulties were exacerbated. Results are discussed in terms of the implications of shyness and screen time in early childhood.

The causality of physical activity status and intelligence: A bidirectional Mendelian randomization study

BACKGROUND

Observational studies suggest physical activity (PA) enhances intelligence, while sedentary behavior (SB) poses a risk. However, causality remains unclear.

METHODS

We extracted genetic instruments from large genome-wide association studies summary data and employed an inverse-variance weighted (IVW) approach within a random-effects model as the primary method of Mendelian randomization (MR) analysis to estimate the overall effect of various physical activity statuses on intelligence. To assess IVW stability and MR sensitivity, we also utilized supplementary methods including weighted median, MR-Egger, and MR-PRESSO. Furthermore, multivariable MR analysis was conducted to examine the independent effects of each physical activity trait on intelligence.

RESULTS

The MR primary results indicated that LST was negatively associated with intelligence (β = -0.133, 95%CI: -0.177 to -0.090, p = 1.34×10-9), while SBW (β = 0.261, 95% CI: 0.059 to 0.463, p = 0.011) may have a positive effect on intelligence; however, MVPA and SC did not show significant effects on intelligence. Inverse causality analyses demonstrated intelligence significantly influenced all physical activity states.

CONCLUSIONS

Our study highlights a bidirectional causal relationship between physical activity states and intelligence.

Screen time and childhood attention deficit hyperactivity disorder: a meta-analysis

OBJECTIVES

The association between screen time and attention deficit hyperactivity disorder (ADHD) has been controversial. This study sheds light on the contentious correlation between screen time and ADHD.

CONTENT

Until August 2022, electronic searches of the PubMed, Embase, and Web of Science databases were carried out. The combined effect value odds ratios (OR) and 95 % confidence interval (95 % CI) were calculated for the meta-analysis using Stata 12.0. There were 81,234 children in the nine studies that made up this meta-analysis which included 28,997 children with ADHD and 52,237 healthy controls. When compared with the screen time <2  h/d, the OR (95 % CI) value of screen time and ADHD in the screen time ≥2 h/d group was 1.51 (1.20-1.90).

SUMMARY AND OUTLOOK

Based on the current meta-analysis results, our study found a positive correlation between screen time and the risk of ADHD. Excessive screen exposure may significantly contribute to the development of ADHD in children. Therefore, it is necessary to reduce screen time per day in children to prevent the occurrence of ADHD.

Prenatal anesthetic exposure and offspring neurodevelopmental outcomes—A narrative review

While it is common for pregnant women to take anesthesia during surgery, the effects of prenatal anesthesia exposure (PAE) on the long-term neurodevelopment of the offspring remain to be clarified. Preclinical animal research has shown that in utero anesthetic exposure causes neurotoxicity in newborns, which is mainly characterized by histomorphological changes and altered learning and memory abilities. Regional birth cohort studies that are based on databases are currently the most convenient and popular types of clinical studies. Specialized questionnaires and scales are usually employed in these studies for the screening and diagnosis of neurodevelopmental disorders in the offspring. The time intervals between the intrauterine exposure and the onset of developmental outcomes often vary over several years and accommodate a large number of confounding factors, which have an even greater impact on the neurodevelopment of the offspring than prenatal anesthesia itself. This narrative review summarized the progress in prenatal anesthetic exposure and neurodevelopmental outcomes in the offspring from animal experimental research and clinical studies and provided a brief introduction to assess the neurodevelopment in children and potential confounding factors.

Association between screen time and developmental and behavioral problems among children in the United States: evidence from 2018 to 2020 NSCH

Excessive digital media use has become the common phenomenon among children's lifestyle, and its influences on the plausible accompanying psychological and behavioral problems are gradually investigated. This study aimed to examine the association between screen time and developmental and behavioral problems of children in the United States (US). A secondary analysis based on the data from the 2018 to 2020 National Survey of Children's Health (NSCH) was conducted. Seven types of developmental and behavioral problems and screen time on weekdays of children were collected through parents/caregivers' recall. Logistic regression models were constructed to determine the associations. Overall, 101,350 children aged between 0 and 17 years old were included in this study and 70.3% of preschoolers aged 0-5 years old and 80.2% of children and adolescents aged 6-17 years old had excessive screen time. Excessive screen time was positively associated with behavioral and conduct problem, developmental delay, speech disorder, learning disability, autism spectrum disorders (ASD), and attention deficit hyperactivity disorder (ADHD) and there were significant dose-response relationships. The association between excessive screen time and developmental and behavioral problems was stronger among preschoolers than among children and adolescents. Boys with excessive screen time showed high odds of most types of developmental and behavioral problems. It can be concluded that children with excessive screen time are at high odds of developmental and behavioral problems, especially for preschoolers and boys. Early intervention of digital media use is urgent and essential for children in the US.

Associations of physical activity and screen time with adolescent idiopathic scoliosis

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common type of idiopathic scoliosis, affecting approximately 0.61%-6.15% adolescents worldwide. To date, the results on the relationship between moderate-to-vigorous physical activity (MVPA) and AIS were inconsistent, and the association between screen time (ST) and AIS remained unclear. This study aimed to describe MVPA and ST among adolescents, and to explore the independent and joint associations between PA, ST, and AIS.

METHODS

A frequency-matched case-control study based on the 2021 Chinese School-based Scoliosis Screening Program in Shenzhen city, south China, was conducted. The research involved 494 AIS patients (aged 9-17 years) and 994 sex- and age-matched healthy controls. MVPA and ST were measured using a self-administered questionnaire. Logistic regression models estimated associations between PA, ST, and AIS.

RESULTS

Compared to subjects meeting the recommended 60-min daily of MVPA, adolescents reporting daily MVPA time less than 60 min had 1.76 times higher odds of experiencing AIS (95% CI: 1.32-2.35) and adolescents reporting daily MVPA in inactive status had 2.14 times higher odds of experiencing AIS (95% CI: 1.51-3.03). Moreover, participants reporting ST for 2 hours or more had 3.40 times higher odds of AIS compared with those reporting ST less than 2 hours (95% CI: 2.35-4.93). When compared with the adolescents reporting both ST and MVPA meeting the guidelines recommended times (ST < 2 h and MVPA ≥ 60 min/day), those reporting both ST ≥ 2 h and MVPA in inactive status are 8.84 times more likely to develop AIS (95% CI: 3.99-19.61).

CONCLUSIONS

This study reported that the insufficient MVPA, especially MVPA in inactive status, and excessive ST were risk factors for AIS. Additionally, the joint effects of insufficient MVPA and excessive ST probably increase the risk of AIS.