Adachi Child Health Impact Of Living Difficulty Research Articles

Impact of COVID-19 pandemic on children overweight in Japan in 2020.

This study aimed to explore the association between the coronavirus disease (COVID-19) pandemic and overweight incidence among preadolescent elementary school children in Japan. A population-based longitudinal study was conducted in Adachi City, Tokyo, Japan, using data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study. The control group (2016-2018) comprised 434 children, and the COVID-19 exposure group (2018-2020) included 3500 children. Overweight was defined as a body mass index (BMI) z-score of 1 SD or more according to the World Health Organization standards. The study design involved comparing BMI z-scores before and after exposure to the pandemic, considering the associated lifestyle changes and potential consequences on physical activity, parental employment status and income. By 6th grade, the prevalence of overweight increased from 17.7% to 19.2% in the control group and 22.5% to 29.5% in the COVID-19 exposure group. Difference-in-differences analysis revealed that children's exposure to COVID-19 significantly increased BMI z-scores (coefficient 0.22, 95% confidence interval (CI) 0.14-0.29) and a higher odds ratio of overweight (odds ratio 2.51, 95% CI 1.12-5.62), even after adjusting for time-varying covariates. The COVID-19 pandemic has been associated with an increased prevalence of overweight among elementary school children in Japan.

Number of siblings and social capital among parents rearing schoolchildren: Results from the A-CHILD study.

Having siblings may foster sociality; however, little is known about whether sibling number determines social capital, the resources obtained through social networks. We examined the association between sibling number and social capital among Japanese parents rearing schoolchildren. We used cross-sectional data from the 2018 and 2019 Adachi Child Health Impact of Living Difficulty (A-CHILD) study, targeting all primary and junior high school students and their parents in Adachi, Tokyo, Japan (n = 8,082). Individual-level social capital was evaluated by assessing caregivers' social cohesion, social support, and group affiliation. All analyses were adjusted for age and sex. An inverse U-shaped association was found between sibling number and social capital. Adults who grew up with 1 or 2, but not ≥3, siblings had greater social support (β = 0.23, 95% confidence interval [CI], 0.06-0.40; β = 0.46, 95% CI, 0.29-0.64, respectively) than those who grew up as an only child after covariate adjustment. Adults who grew up with 2 or 3, but not 1 or ≥4, siblings had greater group affiliation (β = 0.09, 95% CI, 0.03-0.16; β = 0.09, 95% CI, 0.01-0.18, respectively) than those who grew up as an only child after covariate adjustment. Sibling number was not associated with social cohesion. Growing up with 1 to 3 siblings was associated with higher social capital in adulthood than being an only child. Having siblings may provide an opportunity to foster social capital.

Association of maternal pre-pregnancy body mass index with resilience and prosociality of the offspring aged 6-7years old: a population-based cohort study in Japan.

The association between maternal pre-pregnancy obesity and child behavior problems has been widely researched, leaving a gap in understanding the positive aspects of children's mental health. The present study aimed to investigate the association between maternal pre-pregnancy body mass index (BMI) and resilience and prosociality among 6-7year-old children in Japan. A retrospective cohort study was conducted using data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, a population-based study in 2017 and 2019 including all first-grade students in public schools in Adachi, Tokyo, Japan (n = 7328, response rate = 84.7%). Resilience and prosociality were measured by the Children's Resilient Coping Scale and the Strength and Difficulties Questionnaire, respectively. Maternal pre-pregnancy weight and height were reported based on the Mother and Child Health Handbook, and BMI was categorized as underweight (BMI < 18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), and obesity (BMI ≥ 30). Linear regression models were employed to control for covariates. Maternal pre-pregnancy obesity was found to be negatively associated with child resilience (coefficient: -3.29; 95% CI -6.42--0.15), while maternal underweight was negatively associated with child prosociality (coefficient: -0.12; 95% CI -0.24--0.005) compared to mothers of pre-pregnancy normal BMI. Perinatal factors, such as gestational weight gain, gestational age, and birth weight, did not mediate the association. Our findings suggest that maternal pre-pregnancy obesity is linked to decreased resilience and maternal underweight is linked to decreased prosociality in children aged 6-7years. Maintaining an appropriate BMI range before pregnancy may be crucial for enhancing resilience and prosociality of offspring.

Association between skipping breakfast and prediabetes among adolescence in Japan: Results from A-CHILD study.

Adolescents with prediabetes are at high risk of developing type 2 diabetes in later life. It is necessary to identify risk factors for prediabetes in adolescents. This study aimed to examine the association between skipping breakfast and prediabetes among adolescents in Japan. We used the population-based cross-sectional data of eighth grade in junior high school students from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study conducted in Adachi City, Tokyo, Japan, in 2016, 2018, and 2020. Skipping breakfast was assessed using self-reported questionnaires (N=1510). Prediabetes was defined as hemoglobin A1c (HbA1c) levels of 5.6-6.4%. The association between skipping breakfast and prediabetes was evaluated using multivariate logistic regression analysis. Stratified analysis was also performed using BMI, 1 SD or more, or less than 1SD, as overweight was defined as 1SD or more. Students who skipped breakfast were 16.4% (n=248). The prevalence of prediabetes was 3.8% (n=58). Skipping breakfast exhibited a significant association with prediabetes (OR:1.95, 95% CI: 1.03 to 3.69) after adjusting for sex, annual household income, family history of diabetes mellitus, BMI, and survey year. Stratified analysis showed stronger association among students with overweight (BMI ≥1SD) (OR=4.31, 95% CI 1.06-17.58), while non-sigificant among students without overweight (BMI<1SD) (OR=1.62, 95% CI 0.76-3.47). Skipping breakfast in Japanese adolescents, especially those with overweight, was associated with prediabetes. The promotion of avoiding skipping breakfast may help to prevent prediabetes.

Food Categories for Breakfast and Mental Health among Children in Japan: Results from the A-CHILD Study.

There is limited evidence that what children eat for breakfast contributes to their mental health. This study aimed to examine the associations between food categories for breakfast and mental health among children in Japan. A proportion of participants aged 9-10 years in the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in Japan who consumed breakfast daily were included (n = 281). Foods eaten for breakfast were reported by the children each morning for 7 consecutive days, and defined according to the food categories in the Japanese Food Guide Spinning Top. Child mental health was assessed by caregivers using the Strength and Difficulties Questionnaire. The mean intake frequencies per week were six times for grain dishes, two times for milk products, and one time for fruits. Linear regression analysis revealed an inverse association between the frequent intake of grain dishes, whether rice or bread, and problem behaviors after adjustment for potential confounders. However, confectionaries, which mainly consisted of sweet breads or pastries, were not associated with problem behaviors. The intake of non-sweet grain dishes at breakfast may be effective for preventing behavioral problems in children.

School- and community-level protective factors for resilience among chronically maltreated children in Japan.

Few studies have investigated how school- and community-level modifiable factors might enhance resilience, defined as an ability to recover from and cope with adversity, among chronically maltreated pre-adolescent children. This study aims to investigate school and community factors that can increase children's resilience following maltreatment. We used data from the Adachi child health impact of living difficulty (A-CHILD) Study, a population-based prospective longitudinal study starting with first-grade children in all public elementary schools in Adachi City, Tokyo, Japan in 2015. Children who experienced chronic maltreatment while in 1st and 4th grades and whose resilience scores were available at those grades were included in the analysis (N = 789). Crude and multiple regressions were used to examine associations of child-reported school factors (i.e., school social capital, number of friends to consult with) and community factors (i.e., having a non-parental role model and supportive adult, having a third place, which is defined as a place other than home to spend time after school) with parent-reported resilience at 4th grade. These regressions were also performed stratified by sex. School social capital and having a non-parental role model at 4th grade were positively associated with resilience after adjusting covariates, including resilience at 1st grade [coefficient = 3.63, 95% confidence intervals (CI) 2.26-4.99; coefficient = 2.52, 95% CI 0.57-4.38, respectively]. Analysis by sex revealed that having a supportive adult, but not a role model, was associated with resilience among girls (coefficient = 5.50, 95% CI 0.20-10.8). The findings suggest that school and community factors can promote resilience following child maltreatment, and these factors are different between boys and girls.

Association of Adverse Childhood Experiences Including Low Household Income and Peer Isolation With Obesity Among Japanese Adolescents: Results From A-CHILD Study.

BackgroundAdverse childhood experience (ACE) is a major risk factor for obesity in both adults and adolescents. Although, arguably, peer isolation and low household income could be conceived as of ACEs, few studies have included these experiences as ACEs.ObjectivesThis study aims to examine whether ACEs, including peer isolation and low household income, are associated with obesity in adolescents.MethodsWe used pooled data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in 2016 and 2018, which is a school-based cross-sectional study in Adachi City, Tokyo, Japan, N = 6,946, 4th (9–10 years old), 6th (11–12 years old), and 8th (13–14 years old) grades. Among the eight items of ACEs, adolescents assessed one item, including peer isolation, and their caregivers assessed seven other items using questionnaires. The adolescents' body mass index (BMI) was measured in school health checkups and calculated to fit the World Health Organization (WHO) standards. Multinomial logistic regression was applied to investigate the association of the cumulative ACEs and each type of ACE with BMI, in which the study was conducted in 2020.ResultsThe number of ACEs was not associated with overweight or obesity among adolescents after adjusting for covariates. As for each type of ACE, single parenthood and low household income showed a significant independent association with obesity.ConclusionsThe number of ACEs was not associated with overweight or obesity in Japanese adolescents, while single parenthood and low household income showed a significant positive association with obesity. Further longitudinal studies are needed to replicate this association among adolescents.

Association between Children's Engagement in Community Cultural Activities and Their Mental Health during the COVID-19 Pandemic: Results from A-CHILD Study.

Social learning experiences developed through engagement in community cultural activities can affect a child’s development. Few studies have examined how children’s engagement in community activities is related to their mental health. This study aimed to examine associations between children’s participation in community cultural activities and their mental health. We targeted all sixth-grade children in all 69 primary schools in Adachi City, Tokyo, using the Adachi Child Health Impact of Living Difficulty (A-CHILD) study (n = 4391). Parents answered the validated Japanese version of the Strength and Difficulties Questionnaire (SDQ) to assess child mental health, the child’s engagement in community cultural activities. The community activity in which children most frequently participated was local festivals. Participating in local festivals was significantly associated with lower behavioral difficulties (β = −0.49, SE = 0.17, p = 0.005) and higher prosocial behaviors (β = 0.25, SE = 0.07, p < 0.001) after adjusting for demographic variables, family social capital, and parent-child interactions. These results highlight the importance of children’s engagement in community cultural activities for their mental health during the COVID-19 pandemic.

Differential Effects of Multiple Dimensions of Poverty on Child Behavioral Problems: Results from the A-CHILD Study.

The differential effects of low income and material deprivation—in particular, deprivation related to child educational needs—have not been well examined. This study aimed to examine the effects of low income and life-related and child-related deprivation on child behavioral problems. This study used data from first-grade students who participated in the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in 2015, 2017, and 2019 (N = 12,367) in Japan. Material deprivation was divided into life-related deprivation (i.e., lack of items for a living) and child-related deprivation (i.e., lack of children’s books, etc.), and low income was assessed via annual household income. We assessed child behavioral problems and prosocial behavior using the Strengths and Difficulties Questionnaire. One in ten children belonged to low-income families, 15.4% of children experienced life-related deprivation, and 5.4% of children experienced child-related deprivation. While life- and child-related deprivation had significant adverse effects on behavioral problems, they had no association with prosocial behavior. The effects of low income were mediated by parental psychological distress (45.0% of the total effect) and the number of consulting sources (20.8%) on behavioral problems. The effects of life-related and child-related deprivation were mediated by parental psychological distress (29.2–35.0%) and the number of consulting sources (6.4–6.9%) on behavioral problems. Life-related and child-related deprivation, but not low income, are important for child mental health.

Association between Adverse Childhood Experiences and Time Spent Playing Video Games in Adolescents: Results from A-CHILD Study.

Background: Excessive time spent playing video games is associated with adverse health outcomes in adolescents. Although poor child–parent relationship and social relations with peers are considered as possible predictors, little is known as to whether adverse childhood experiences (ACEs) are associated with time spent playing video games. The aim is to examine the association between ACEs and time spent playing video games in adolescents. Methods: We used pooled data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in 2016 and 2018, which is a population-based cross-sectional study in Adachi City, Tokyo, Japan (N = 6799, 4th, 6th, and 8th-grade students). Adolescents answered questionnaires examining the time spent playing video games, per day, on weekdays (“less than 1 h”, “less than 3 h”, and “more than 3 h”) and ACEs (eight types). Results: The results of the ordinal logistic regression analysis showed a positive association between ACE total score and time spent playing video games after adjusting for covariates (1 ACE: OR = 1.28, 95% CI = 1.10–1.48; 2 ACEs: OR = 1.25, 95% CI = 1.06–1.48; 3 + ACEs: OR = 1.44, 95% CI = 1.14–1.82, p for trend < 0.001). Regarding each type of ACE, the experiences of single parenthood, parental history of psychiatric disorders, and peer isolation were independently positively associated with time spent playing video games. Conclusions: Health policy to address ACEs might be important to shorten the time spent playing video games.

Association of Birth Order With Mental Health Problems, Self-Esteem, Resilience, and Happiness Among Children: Results From A-CHILD Study.

Objective: This study aimed to investigate the association of birth order with mental health problems, self-esteem, resilience, and happiness among children aged 9–10 years.Methods: This was a cross-sectional study using data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, which was a population-based study of children in fourth grade in public schools in Adachi City, Tokyo, Japan in 2018 (N = 3,744). Parent-rated Strengths and Difficulties Questionnaire (SDQ) and self-rated resilience, happiness, and self-esteem score were used to assess child mental health. Multiple regression analysis for continuous outcomes and logistic regression for dichotomous outcomes were used to examine the association of birth order with mental health problems, resilience, happiness, and self-esteem. The analysis was controlled for child sex, mother's age, mother's education, caregiver's depressive symptoms, household income, and living with grandparents.Results: Last-borns showed the lowest total difficulties score in the SDQ, while only children showed the highest (p < 0.001). The highest prosocial behaviors score was found among last-borns (p < 0.001). Resilience score was also highest among last-borns, followed by first-borns, middle-borns, and only children. The lowest happiness score was found among middle-borns. Self-esteem score did not differ by sibling types. These associations were similar in the adjusted model and dichotomized outcomes model.Conclusions: Differential impacts of birth order on child mental health, for both positive and negative sides, were found. Further research is warranted to elucidate the mechanism of the association between birth order and the development of behavior problems and the positive aspects such as resilience, happiness, and self-esteem among children.

Association Between Parenting and School Refusal Among Elementary School Children in Japan: Results From A-CHILD Longitudinal Study.

Objective: The aim of this study was to examine the association between parenting, including the parent–child interaction and child maltreatment in the first grade (6–7 years old), and school refusal in the second (7–8 years old) and fourth (9–10 years old) grades among elementary school children in Japan.Methods: Data were from the Adachi Child Health Impact of Living Difficulty (A-CHILD) longitudinal study conducted in 2015, 2016, and 2018 in Adachi City, Tokyo, Japan. A questionnaire was distributed to all the first-grade school children (N = 5,355) in 2015. Of the total 4,291 valid children (response rate: 80.1%), 3,590 and 3,070 children were followed up to the second and fourth grades, respectively. Caregivers responded to the questionnaire on the parent–child interaction and child maltreatment, including neglect, physical abuse, and psychological abuse in the first grade and school refusal in the second and fourth grades. We conducted multiple imputation for missing data. Multivariate logistic regression model was used for this analysis adjusting for child mental health in the first grade and sociodemographic characteristics.Results: Prevalence of school refusal was 1.8% (n = 64) in the second grade and 2% (n = 60) in the fourth grade. We found no association of the parent–child interaction and child maltreatment in the first grade and with school refusal in the second and fourth grades, respectively, after adjusting for covariates.Conclusions: Parenting, such as the parent–child interaction and child maltreatment, may not be associated with school refusal among elementary school children. Further longitudinal research is needed to elucidate other factors, such as peer relationships and school environment, which can affect school refusal.

Association of home cooking with caregiver-child interaction and child mental health: results from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study.

To examine the associations of home cooking with caregiver-child interaction and child mental health in Japan. Cross-sectional data collected in 2018. Frequency of home cooking was assessed by a questionnaire among 4126 caregivers and classified as high (almost every day), medium (4-5 d/week) or low (≤3 d/week). Caregiver-child interaction was evaluated by assessing frequency of talking and playing together (per week). Behaviour problems and prosocial behaviour were assessed by the Strengths and Difficulties Questionnaire, and resilience was assessed using the Children's Resilient Coping Scale. Japan. Children aged 9-10 years and their caregivers in Adachi, Tokyo, Japan. Low and middle frequency of home cooking were associated with lower frequencies of talking about school life, talking about news with the child, talking about television shows with the child and helping with the child's homework. Children with low and/or middle frequency of home cooking had more behaviour problems (low frequency: β = 3·95, 95 % CI 1·30, 6·59 and medium frequency: β = 3·38, 95 % CI 2·07, 4·70), lower prosocial behaviour (low frequency: β = -5·85, 95 % CI -10·04, -1·66) and lower resilience (low frequency: β = -6·56, 95 % CI -9·77, -3·35 and medium frequency: β = -4·11, 95 % CI -5·71, -2·51), compared with children with high frequency of home cooking after adjusting covariates including socio-economic status. These associations were mediated by child's eating behaviours and/or caregiver-child interaction. Creating an environment that encourages caregivers to cook at home may be important for children's mental health.

The Association of Passive Smoking and Dyslipidemia Among Adolescence in Japan: Results From A-CHILD Study.

Passive smoking in childhood has been reported to be associated with dyslipidemia in Western countries. However, this association in Asian countries remains unclear. Further, no study has investigated the sex difference of the association. This study aimed to elucidate the association between passive smoking and dyslipidemia in adolescent boys and girls in Japan. We used a cross-sectional data of junior high school students in the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in Adachi City, Tokyo, Japan in 2016 and 2018. Of the 1431 available students, 1166 students and their parents responded to the survey, including frequency of passive smoking (response rate 81.5%). We assessed dyslipidemia using total cholesterol (TC) levels, low-density lipoprotein cholesterol (LDL-C) levels and high-density lipoprotein cholesterol (HDL-C) levels. The association between passive smoking and dyslipidemia was evaluated by using multivariate regression analyses adjusted for socioeconomic status and lifestyle factors stratified by boys (N = 564) and girls (N = 602). Among boys, HDL-C levels were significantly lower if exposed to passive smoking frequently, compared with those not exposed (β = -3.19; 95% CI, -5.84 to -0.55). However, this trend does not hold true among girls. Passive smoking was not associated with TC levels and LDL-C levels in either boys or girls. We found that exposure to passive smoking was associated with HDL-C level among boys in Japan, but not in girls. Further longitudinal study is needed to confirm the association between passive smoking and dyslipidemia among boys in Japan.

Association Between Serum Lipid Levels, Resilience, and Self-Esteem in Japanese Adolescents: Results From A-CHILD Study.

Previous studies have found that serum lipid levels independently associate with mental health problems in adulthood. However, little is known about the association between serum lipid levels and positive aspects of mental health such as resilience and self-esteem, which develop in adolescence. The aim of this study is to examine the association between serum lipid levels and resilience and self-esteem in Japanese adolescents. Data were pooled data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study in 2016 and 2018, a school-based, cross-sectional study in Adachi City, Tokyo, Japan (N = 1,056, aged 13–14 years). Resilience of the child was assessed by caregivers, and self-esteem was self-identified via questionnaires. Serum lipid levels [total cholesterol, low-density lipoproteins (LDL), and high-density lipoproteins (HDL)] were assessed in school health checkup, in addition to height and weight measurements. Multiple linear regression was applied to investigate the association between standardized serum lipid levels and resilience and self-esteem. LDL showed inverse association with resilience [β = −1.26, 95% confidence interval (CI) = −2.39 to −0.14] after adjusting for child’s BMI, month of birth, sex, absence of parent, household income, caregiver’s mental health, and lifestyle (e.g., habits of eating, physical activity, and sleep). We also found an inverse association of total cholesterol and higher LDL cholesterol with self-esteem (β = −0.58, 95% CI = −0.99 to −0.18; β = −0.42, 95% CI = −0.83 to −0.01, respectively). HDL cholesterol was not associated with resilience and self-esteem. Among Japanese adolescent, total and LDL cholesterol may be biomarkers of resilience and self-esteem.

Adachi Child Health Impact of Living Difficulty (A-CHILD) Study: Research Protocol and Profiles of Participants.

BackgroundThe Adachi Child Health Impact of Living Difficulty (A-CHILD) study has been conducted since 2015 to clarify the associations between socioeconomic factors and child health, as well as to accumulate data for political evaluation of the child-poverty agenda. This paper describes the purpose and research design of the A-CHILD study and the baseline profiles of participants, together with the future framework for implementing this cohort study.MethodsWe have conducted two types of continuous survey: a complete-sample survey started in 2015 as a first wave study to target first-grade children in all public elementary schools in Adachi City, Tokyo, and a biennial fixed grade observation survey started in 2016 in selected elementary and junior high schools. Questionnaires were answered by caregivers of all targeted children and also by the children themselves for those in the fourth grade and higher. The data of A-CHILD also combined information obtained from school health checkups of all school-grade children, as well as the results from blood test and measurement of blood pressure of eight-grade children since 2016.ResultsThe valid responses in the first wave were 4,291 (80.1%). The number of households in “living difficulties”, such as low household income or material deprivation, stood at 1,047 (24.5%).ConclusionsThe A-CHILD study will contribute to the clarification of the impact of poverty on children’s health disparities and paves the way to managing this issue in the community.

The impact of public assistance on child mental health in Japan: results from A-CHILD study.

Public assistance is one option for providing a safety net to protect the health of children, but assistance may also generate feelings of shame that impact self-esteem. This study aims to elucidate the impact of public assistance on child mental health. We used cross-sectional data on 6920 first graders from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study. We found children living in relative poverty had more behavioral problems, low resilience, and were likely to refuse to go to school. After propensity-score matching among low-income households, the likelihood of children refusing to go to school was larger in the families receiving assistance as compared to non-recipients (OR 4.00, 95% CI 0.85-18.84) although there were no significant differences between recipients and non-recipients in low-income households. Our study produced insufficient evidence to indicate that social assistance is associated with child mental health, resilience, or school refusal.

Association of Existence of Third Places and Role Model on Suicide Risk Among Adolescent in Japan: Results From A-CHILD Study.

Objective: Low self-esteem among adolescents can be considered a risk factor for suicidal behavior in adolescents. Thus, the purpose of this study is to investigate the association between the existence of a third place and role model on self-esteem among adolescents in Japan, where low self-esteem is prevalent among adolescents.Methods: We analyzed data from the 2016 Adachi Child Health Impact of Living Difficulty (A-CHILD) study, in which a school-based questionnaire was conducted among children in grades 4, 6, and 8 living in Adachi City, Tokyo (N = 1,609). Children self-rated their own levels of self-esteem. Low self-esteem was defined as lower 10 percentile group. The existence of a third place was defined as a place where children spent time after school other than the home or school campus, and role model was defined as having someone, other than a parent, who they looked up to, and these concepts were assessed via questionnaire.Results: Adolescents without a third place and role model accounted for 10.5 and 6.1%, respectively. We found that children who lacked a third place also showed a significant association with low self-esteem (OR: 1.75, 95% confidence interval (CI): 1.09–2.81), and those who lacked a role model were 3.34 times more likely to have lower self-esteem (95% CI: 1.98–5.62).Conclusion: The existence of a third place and a role model may be important to prevent low self-esteem among adolescents in Japan.

Toothbrushing and School Refusal in Elementary School: A Longitudinal Study.

The aim of this study was to examine the association between toothbrushing frequency and school refusal among elementary school children. We used data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) longitudinal study conducted between 2015 and 2016 in Adachi City, Tokyo, Japan. A questionnaire was distributed to all first-grade children aged 6 to 7 years (N = 3697, follow-up rate: 86.2%). Propensity score (PS) matching was applied to collapse the known covariates on toothbrushing frequency in grade 1 on the association with school refusal in grade 2. Among the followed children, 2.4% showed school refusal in grade 2 (89 children) and 23.5% (870 children) brushed their teeth once or less than once daily in grade 1. After propensity score matching, children with toothbrushing once or less than once daily in grade 1 were 2.25 (95% CI: 1.25–4.05) times more likely to show school refusal in grade 2, compared with those with toothbrushing twice or more a day. Our findings suggest that toothbrushing once or less than once daily is an independent risk factor for school refusal among children. Oral health promotion to recommend toothbrushing more than once a day could prevent school refusal. Further intervention studies investigating the mechanism and causality are warranted.

Prevention of dental caries by eating vegetables at the beginning of a meal in Japanese children

Abstract Backgrounds Dental caries is still a worldwide serious problem among children. Previous studies showed that higher consumption of vegetables prevents dental caries. Eating order habits, such as eating vegetables at the beginning of a meal, called “Vege-first”, may increase the amount of vegetable consumption, and in turn, prevent dental caries. We used cross-sectional data in our previous study to show the association between “Vege-first” and dental caries. However, the causal relationship of “Vege-first” on dental caries is not clear. The aim of this study to investigate the effect of “Vege-first” on dental caries, using cohort data of Japanese elementary students. Methods We used cohort data from 2015 to 2016 by the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, a population-based study of all first- and Second- grade students in Adachi City, Tokyo, Japan. The number of DMFT (decayed, missed due to decay, and filled teeth) in 2016 was used as an outcome. Poisson regression analyses were applied to determine the independent association between keeping the “Vege-first” habit over one year and the number of DMFT in 2016 after controlling for the effects of a child's sex, parental marital status, socioeconomic status, and child's dental caries status in 2015. Results Of 3,164 valid participants, 45.0% had dental caries and 6.3% kept the “Vege-first” habit. Children who kept the “Vege-first” habit had fewer DMFTs in 2016 than children who did not (p &amp;lt; 0.001). After controlled for covariates, children with having a continuous “Vege-first” habit were still significantly and independently decreased the number of DMFT in 2016 (Incidence-rate ratios=0.87 (95% confidential interval [0.75-0.98])). Conclusions This study showed that having the continuous “Vege-first” habit was associated with preventive dental caries even after accounting for socioeconomic status. Health policy introducing the “Vege-first” habit may be effective to prevent pediatric dental caries. Key messages The practice of eating vegetables at the beginning of a meal, called “Vege-first” may increase vegetable consumption and reduce dental caries. The continuous habit of 'Vege-first' was effective in preventing a child’s dental caries even if after accounting for socioeconomic status.