BACKGROUND: This study aimed to investigate the difference between cycloplegic and noncycloplegic refraction and evaluate the pseudomyopia prevalence in Chinese preschool children during the outbreak of COVID-19.
METHODS: A cross-sectional study was conducted in the Tongzhou District of Beijing, China. Refractive error was measured under both noncycloplegic and cycloplegic conditions with autorefraction. The difference between noncycloplegic and cycloplegic spherical equivalent refraction (SER) and pseudomyopia prevalence were analyzed. Pseudomyopia was defined as SER ≤-0.50D in precycloplegic assessments and >-0.50D in post-cycloplegic assessments.
RESULTS: Out of the 1487 participants who were enrolled in the study, 1471 individuals (98.92%) between the ages of 3-6 years completed all required procedures. A statistically significant difference in refraction was observed between noncycloplegic and cycloplegic measurements, the median of difference in spherical equivalent refraction (SER) of 0.88D (dioptre)(0.50,1.38). There was a high intraclass correlation (ICC) between these two methods for cylinders (ICC = 0.864; 95% CI, 0.850-0.877). The median DSE for myopia, emmetropia and hyperopia were 0.25D (0.00, 0.38),0.25D (0.06, 0.50) and 1.00D (0.62, 1.38), an hypermetropes showed considerably greater differences than myopes and emmetropes (Kruskal-Wallis test, H = 231.023, P = 0.000). Additionally, girls displayed a greater DSE than boys. Furthermore, when comparing against-the-rule (ATR) and oblique astigmatism, it was found that with-the-rule (WTR) astigmatism had the largest DSE. The study found varying prevalence rates of myopia, emmetropia, and hyperopia with and without cycloplegia, which were 1.90% vs. 10.06%, 11.49% vs. 50.31%, and 86.61% vs. 39.63%, respectively. Additionally, the overall prevalence of pseudomyopia was determined to be 8.29%. Participants with pseudomyopia had a significantly higher mean difference in SER (DSE) compared to non-pseudomyopic participants.
CONCLUSIONS: Cycloplegic refraction is more sensitive than a noncycloplegic one for measuring refractive error in preschool children. Pseudomyopia is prevalent in preschool children during the COVID-19 outbreak period. Our study indicates the possibility that cycloplegic refraction should be performed in preschool children routinely.

Although maternal adverse childhood experiences (ACEs) are known to be related to the emotional and behavioral problems (EBPs) of offspring, few studies have surveyed the intergenerational effects of paternal ACEs. In addition, no study has yet explored the combination and interaction effects of maternal and paternal ACEs on preschool children\'s EBPs in China, and the gender differences in these relationships also remain to be explored. A total of 3,575 preschool children from 12 preschools from Hefei city of Anhui province were included in this study. We used a binomial logistic regression to examine the relationship between maternal ACEs, paternal ACEs and children\'s EBPs. Logistic regression analysis indicated that maternal and paternal ACEs were significantly related to EBPs in children, respectively. The high maternal ACEs + high paternal ACEs group had the greatest association with children\'s EBPs. Interaction analysis results showed that, compared with the reference group (low maternal ACEs×low paternal ACEs), the other group (high maternal ACEs×high paternal ACEs ) were significantly related to children\'s EBPs (OR = 1.84, 95%CI: 1.55-2.19). We found that there were no gender differences in the combination and interaction effects (P>0.05). When fathers and mothers were jointly exposed to high levels of ACEs, children had a higher risk of developing EBPs than when they were exposed independently. Future studies should fully explore the intergenerational health effects of parental ACEs so that references for promoting the physical and mental health of preschool children can be developed.

Black stain (BS) and caries are common oral issues in children worldwide. This study aimed to reveal the prevalence of BS and caries in primary dentition of children in Qingdao, China and evaluate the potential association between them. A total of 672 preschool children aged 3-5 years old from 12 kindergartens in Qingdao, northern China were enrolled in the study. The prevalences of BS and caries were counted, and their distributions across different ages and genders were analyzed. The potential protective role of BS (independent variable) on caries (dependent variable) was analyzed via binary logistic regression analysis. BS was observed in 103 children (15.33%), including 3 severe- (0.45%), 28 moderate- (4.17%), and 72 mild (10.71%) forms. Caries was observed in 374 children (55.65%) and it was positively associated with age. Notably, the prevalence of caries was lower in children with BS than in those without BS (42.72% vs. 58.00%, respectively). Children with BS were less likely to suffer from caries than those without BS. BS in mild or moderate/severe forms was associated with a low risk of caries. In summary, the prevalence of BS in primary dentition in Qingdao, China is at a relatively high level worldwide. BS is a protective factor for caries in primary dentition.

BACKGROUND: Preschool represents the budding and initial stage of bullying behavior, where perpetration of physical bullying predominates as the primary form of bullying. An in-depth understanding of the factors linked to preschool physical bullying behavior is crucial for enabling early prevention and intervention strategies.
OBJECTIVE: The purpose of this study was to examine the relationship between Theory of Mind and physical bullying behavior in 4-6 years old children in kindergarten and the mediating role of peer rejection and gender in this relationship.
METHODS: Data on perpetration of physical bullying and peer rejection were obtained from 310 preschool children (age range = 52-79 months, M = 66.85, SD = 7.04) by the peer nomination method, and their Theory of Mind was measured by the Theory of Mind Development Scale.
RESULTS: The results showed that Theory of Mind negatively predicted perpetration of physical bullying in preschool children and that Theory of Mind was related to perpetration of physical bullying in preschool children only through peer rejection. Boys were also found to have a stronger association between peer rejection and perpetration of physical bullying in preschool children than girls.
CONCLUSIONS: Peer rejection may play a mediating role between Theory of Mind and perpetration of physical bullying in preschool children. In addition, the relationship between peer rejection and perpetration of physical bullying appears to be stronger for boys than for girls. This contributes to our understanding of the relationship between Theory of Mind and perpetration of physical bullying in preschool children and has implications for how bullying prevention and intervention can be tailored to the gender of young children.

In the Chinese cultural context, the collaborative interaction characteristics among three key entities - families, kindergartens, and communities - and the mechanisms of their correlation with preschool children\'s social behavior problems have not been fully understood yet. Based on ecological systems Theory and social support theory, this study aimed to examine the correlation between parent-teacher relationships and preschool children\'s social behavior problems in Chinese kindergartens, as well as the mediating role of parents\' work-family conflict and parenting self-efficacy. Structural equation modeling was used to test the research hypotheses based on a questionnaire survey of 1,784 parents of preschool children. The main findings of this study are as follows: (1) Parents\' perceived positive parent-teacher relationships are negatively correlated with preschool children\'s social problems. (2) Parents\' work-family conflict and parenting self-efficacy mediate the relationship between parent-teacher relationships and preschool children\'s social behavior problems; (3) Parents\' work-family conflict and parenting self-efficacy play a chain mediating role in the influence of the parent-teacher relationship on preschool children\'s social behavior problems. Taken together, the results collectively further elucidate the correlation between parent-teacher relationships and preschool children\'s social behavior problems, while also discussing other relevant factors pertaining to children\'s social behavior problems. Theoretically, this study expands the understanding of how external environmental resources interact with home and family education. Practically, this research indicates that governments, early childhood education institutions, and workplaces need to strengthen their support for family education of preschool children. The findings contribute to promoting a multi-faceted co-operation aimed at enhancing the quality of early childhood education and fostering the social adaptability and holistic development of preschool children.

Promoting appropriate behaviors in early childhood is crucial for children\'s future development. This systematic review aimed to explore the efficacy of social story (SS) intervention in teaching expected behaviors among preschool children. A structured search strategy was applied to five online electronic databases. The references were systematically screened in accordance with the PRISMA statements. Randomized or non-randomized controlled studies, as well as single-subject studies, in which SSs served as a behavioral training approach for children aged 2 to 6 years were included. Information related to study design, characteristics of the participants, target behaviors, and implementation of SS intervention was extracted. A meta-analysis was performed using the random-effects model, where similar outcomes were evaluated by similar intervention across multiple studies. Twenty-one studies were identified for qualitative analysis, while two studies formed the basis of the meta-analysis. SS interventions were employed to teach a variety of behaviors among typically developing children as well as those with various disabilities, such as autism, developmental delay, hearing impairments, attention deficit hyperactivity disorder, or other disabilities. The target behaviors included oral health practices, peer interaction, staying on-task, self-regulation, sleep habits, and controlling aggressive behavior during group activities. The SSs were used either alone or combined with other strategies, such as positive reinforcement, music therapy, role play, group discussion, video self-modeling, immediate practices, or additional audio commentary. Most studies reported improvements in appropriate behaviors and/or reductions in unfavorable behaviors. The meta-analysis indicated that children practiced more toothbrushing steps when using SS interventions compared to conventional oral health instruction (Z = 3.60, MD = 0.66, 95%CI 0.30 to 1.02, p < 0.001). SS interventions have the potential to teach target behaviors, particularly toothbrushing behaviors, among preschool children. More well-designed randomized controlled trials are warranted to determine the efficacy of SS interventions among children with various developmental profiles.

The impact of milk on bone health in rural preschoolers is under-researched. This study, through a clinical trial and a meta-analysis, finds that milk supplementation enhances forearm and calcaneus bone acquisition in children, supporting the benefits of daily milk consumption.
OBJECTIVE: This study evaluated the impact of dairy supplementation on bone acquisition in children\'s limbs through a cluster-randomized controlled trial and a meta-analysis.
METHODS: The trial involved 315 children (4-6 year) from Northwest China, randomized to receive either 390 ml of milk daily (n = 215) or 20-30 g of bread (n = 100) over 12 months. We primarily assessed bone mineral density (BMD) and content (BMC) changes at the limbs, alongside bone-related biomarkers, measured at baseline, the 6th and 12th months. The meta-analysis aggregated BMD or BMC changes in the forearm/legs/calcaneus from published randomized trials involving children aged 3-18 years supplemented with dairy foods (vs. control group).
RESULTS: Of 278 completed the trial, intention-to-treat analysis revealed significant increases in BMD (4.05% and 7.31%) and BMC (4.69% and 7.34%) in the left forearm at the 6th and 12th months in the milk group compared to controls (P < 0.001). The calcaneus showed notable improvements in BMD (2.01%) and BMC (1.87%) at 6 months but not at 12 months. Additionally, milk supplementation was associated with beneficial changes in bone resorption markers, parathyroid hormone (- 12.70%), insulin-like growth factor 1 (6.69%), and the calcium-to-phosphorus ratio (2.22%) (all P < 0.05). The meta-analysis, encompassing 894 children, indicated that dairy supplementation significantly increased BMD (SMD, 0.629; 95%CI: 0.275, 0.983) and BMC (SMD, 0.616; 95%CI: 0.380, 0.851) (P < 0.05) in the arms, but not in the legs (P > 0.05).
CONCLUSIONS: Milk supplementation significantly improves bone health in children\'s forearms, underscoring its potential as a strategic dietary intervention for bone development. Trial registration NCT05074836.

The study aimed to examine the performance on linguistic and cognitive tasks among Chinese preschool children with and without autism spectrum disorder (ASD) and explore the direct and indirect relationships between theory of mind (ToM) and literal and inferential listening comprehension. Forty-nine (N = 49) children with ASD and fifty-two (N = 52) age- and gender-matched typically developing (TD) children participated in the study. All participants were administered tasks evaluating their listening comprehension of literal and inferential statements, ToM, as well as verbal and nonverbal IQ. Results showed that the ASD group performed statistically worse on listening comprehension, ToM abilities, verbal IQ, and nonverbal IQ than their TD peers. Further, we found statistically significant correlations between general ToM performance and overall listening comprehension among Chinese preschool children with and without ASD. More specifically, ToM abilities of children with ASD had an indirect effect on their literal listening comprehension via the mediation of verbal IQ, whereas ToM performance among TD children predicted their literal listening comprehension via the mediation of nonverbal IQ. The major findings were discussed in detail based on the situation model. The research facilitated insights into listening comprehension among Chinese preschool children with and without ASD, providing their caregivers and teachers with viable strategies to improve their listening comprehension.

UNASSIGNED: Pediatric pneumonia presents a significant global health challenge, particularly in low- and middle-income countries. This study aimed to investigate the incidence of pneumonia in preschool children in Urumqi and its association with indoor environmental factors.
UNASSIGNED: This case-control study collected data from December 2018 to December 2019 on 1522 preschool children in Urumqi (779 boys and 743 girls) who were diagnosed with pneumonia by a physician. A control group of children who had never had pneumonia was matched in a 1:1 ratio based on gender, age, and ethnicity. Using questionnaires, data were collected on children\'s general characteristics, passive smoking, types of housing, flooring materials, and indoor dampness, analyzing potential factors associated with the incidence of pediatric pneumonia.
UNASSIGNED: Multivariate analysis revealed that cesarean birth (odds ratio [OR] = 1.27; 95 % confidence interval [95%CI] = 1.08-1.48), being an only child (OR = 1.32; 95%CI = 1.13-1.55), antibiotic treatment during the first year of life (OR = 2.51; 95%CI = 1.98-3.19), passive smoking during the mother\'s pregnancy (OR = 1.62; 95%CI = 1.24-2.13), living in multi-family apartment housing (OR = 1.64; 95%CI = 1.28-2.10) and other types of housing (OR = 1.47; 95%CI = 1.09-1.99), laminate flooring (OR = 1.31; 95%CI = 1.01-1.72), and tile/stone/cement flooring flooring (OR = 1.31; 95%CI = 1.06-1.61), and dampness in dwelling (during first year of mother\'s pregnancy) (OR = 1.30; 95%CI = 1.04-1.63) were risk factors for pediatric pneumonia. The use of fresh air filtration systems in children\'s residences (OR = 0.66; 95%CI = 0.50-0.86) was identified as a protective factor.
UNASSIGNED: This study underscores the importance of indoor environmental factors in the prevention of pediatric pneumonia. Public health strategies should consider these factors to reduce the incidence of pneumonia in children. Future research needs to be conducted over a broader geographical range and consider a more comprehensive range of factors influencing pediatric pneumonia.

The impact of the Coronavirus Disease 2019 (COVID-19) on society is continuous, resulting in negative psychological consequences. Given the vulnerability and sensitivity to the environment among preschool children, their emotional and behavioral problems deserve more attention. The current study aimed to explore the impact of the epidemic on preschool children\'s mental health by determining the pooled prevalence of emotional and behavioral problems amidst the Coronavirus Disease 2019 pandemic and to reveal potential reasons for variations between studies. Published studies were searched in Embase, PubMed, ProQuest, PsycINFO, Web of Science, CNKI, and Wanfang. Based on the inclusion criteria outlined in this study, a total of 10 studies encompassing 38,059 participants were incorporated. Employing a random-effect model for estimating the prevalence of emotional and behavioral problems, the results revealed a pooled prevalence rate of 24.3% (95% CI, 0.15-0.38; I²=99.9%) among preschool children. This rate surpasses the pre-outbreak prevalence observed in different countries, signifying a detrimental influence of the epidemic on the mental well-being of preschoolers. Therefore, mental health care and recovery are essential for the vulnerable group during and after the public health crisis. Specific emotional and behavioral problems among preschool children are expected to be researched in the future to provide more targeted guidance for intervention.