Effect of maternal fish oil supplementation during lactation on socioemotional wellbeing and physical activity in 13-year-old children: A randomized clinical trial

Early dietary long-chain n-3PUFA (n-3LCPUFA) may affect brain development. We investigated if fish oil supplementation of lactating mothers affected socioemotional wellbeing in adolescents in a potentially gender-specific manner. At age 13, we invited 92 children of mothers who completed a randomized trial with 1.5 g/d n-3 LCPUFA or olive oil during the first 4 months of lactation and 48 children of mothers with a high habitual fish intake. Children and parents answered validated questionnaires regarding socioemotional wellbeing and physical activity was monitored by ActiGraph for 7 days. Participation rate was 71%. Univariate correlations between children's and parents' ratings on the individual scales were moderate-strong, but correlations across questionnaires indicated that parents might base their ratings on proxy markers. We found no group differences in self-rated socioemotional outcomes or physical activity. Although the study was small, it was the first follow-up on effects of perinatal n-3LCPUFA supply on socioemotional wellbeing in adolescence.

Maternal exposure to psychosocial job strain during pregnancy and behavioral problems in the 11-year-old children: a Danish cohort study

Maternal psychosocial stress may impact child neurodevelopment, but little is known regarding psychosocial job strain. We hypothesized high psychosocial job strain during pregnancy was associated with behavioural problems in the 11-year-old children. Mothers in the Danish National Birth Cohort (1996-2002) were included if they worked, provided information on job strain [Karasek's model: high job strain (often job demand/seldom job control) and passive (seldom or sometimes job demands/seldom job control)] during early pregnancy. At the 11-year follow-up, children (N = 30,592), mothers (N = 30,993), and teachers (N = 12,810) responded to the Strength and Difficulties Questionnaire (SDQ), a screening tool for child behaviour. Scores for hyperactivity, conduct, emotional and peer problems were dichotomised [80% (no) vs. 20% (yes)] according to Danish norms (yes/no). Maternal job strain was not associated with behavioural problems with teachers as informants. When assessed by child or mother, high maternal job strain increased risk of child behavioural problems, but risks were more pronounced for mothers in passive jobs [maternal assessment of total difficulties/odds ratio (95% confidence interval): high strain-girls: 1.16 (0.97-1.40); boys: 1.24 (1.02-1.50). Passive girls: 1.43 (1.21-1.68); boys: 1.25 (1.05-1.49)]. This is one of the first studies on this topic. The different types of maternal job strain were partly associated with child behavioural problems at 11 years; more so if mothers worked in passive rather than the hypothesized high strain jobs. Findings showing dependency on informant could not only indicate unmeasured confounding or rater's bias, but also selection in the smaller numbers of teacher informants or different environments of interaction with the children.

Effects of oily fish intake on cognitive and socioemotional function in healthy 8-9-year-old children: the FiSK Junior randomized trial

BACKGROUND

Long-chain n-3 PUFAs (n-3 LCPUFAs) accrete in the brain during childhood and affect brain development. Randomized trials in children show inconsistent effects of n-3 LCPUFAs on cognitive and socioemotional function, and few have investigated effects of fish per se.

OBJECTIVES

We aimed to investigate the effects of oily fish consumption on overall and domain-specific cognitive and socioemotional scores and explore sex differences.

METHODS

Healthy 8-9-y-old children (n = 199) were randomly allocated to receive ∼300 g/wk oily fish or poultry (control) for 12 ± 2 wk. At baseline and endpoint, we assessed attention, processing speed, executive functions, memory, emotions, and behavior with a large battery of tests and questionnaires and analyzed erythrocyte fatty acid composition.

RESULTS

One hundred and ninety-seven (99%) children completed the trial. Children in the fish group consumed 375 (25th-75th percentile: 325-426) g/wk oily fish resulting in 2.3 (95% CI: 1.9, 2.6) fatty acid percentage points higher erythrocyte n-3 LCPUFA than in the poultry group. The overall cognitive performance score tended to improve by 0.17 (95% CI: -0.01, 0.35) points in children who received fish compared with poultry, supported by n-3 LCPUFA dose dependency. This was driven mainly by fewer errors [-1.9 (95% CI: -3.4, -0.3)] in an attention task and improved cognitive flexibility measured as faster reaction time [-51 ms (95% CI: -94, -7 ms)] in a complex relative to a simple task ("mixing cost"). The fish intervention furthermore reduced parent-rated Strength and Difficulties Questionnaire total difficulties by -0.89 (95% CI: -1.60, -0.18) points mainly due to a -0.63 (95% CI: -1.11, -0.16) points reduction in internalizing problems that was reflected in tendency to a decrease in the overall socioemotional problems score of -0.13 (95% CI: -0.26, 0.01) points. The overall effects were similar in boys and girls.

CONCLUSIONS

Oily fish dose-dependently improved cognitive function, especially attention and cognitive flexibility, and reduced socioemotional problems. The results support the importance of n-3 LCPUFAs for optimal brain function and fish intake recommendations in children.The trial was registered at www.clinicaltrials.gov as NCT02809508.

Effects of early childhood otitis media and ventilation tubes on psychosocial wellbeing - A prospective cohort study within the Danish National Birth Cohort

BACKGROUND

Otitis Media (OM) is one of the most common infections among children in developed countries and may result in temporary conductive hearing loss (HL) if accompanied by middle ear effusion (MEE). Ventilation tube insertion (VTI) is recommended as treatment for recurrent acute OM or chronic MEE with HL. HL may lead to impaired development of psychosocial skills. However, evidence for the developmental consequences of OM and the effect of VTI is inconsistent. The objectives of this study were to investigate 1) whether OM in early childhood is associated with long-term consequences of psychosocial development and 2) if VTI prevents the possible negative consequences of OM.

METHODS

This study examined prospectively collected data from 52.877 children registered in the Danish National Birth Cohort (DNBC). Information about previous OM-episodes and VTI was obtained through systematic follow-up interviews at seven years, and The Strength and Difficulties Questionnaire (SDQ) containing questions about psychological wellbeing was completed. Five groups were defined based on OM-exposure and the presence of VTI. Baseline characteristics were analysed, and comparison of mean SDQ-scores for the five exposure groups was conducted. Means were adjusted for à priori defined confounding factors.

RESULTS

Data from 52,877 children in the DNBC showed an association between OM and poorer SDQ-scores. VTI was associated with an additional increase, i.e. worsening, of the SDQ-score for boys, and only a slight beneficial effect on the girls' outcome. The groups differed in their baseline characteristics in e.g. maternal education, socio-economic status, breastfeeding, and prematurity.

CONCLUSION

Significant associations between parent-reported OM in early childhood and later psychosocial health difficulties were found. VTI did not resolve this association.

Translation and psychometric validation of a Danish version of the medication-related quality of life scale

Background Generic and disease specific health-related quality of life scales have been found to be non-responsive to changes in medications in polypharmacy patients. The Taiwanese medication-related quality of life (MRQoL) scale aims to measure the effect of medication use on patients' quality of life. Objective To evaluate the psychometric properties of the Danish translation of MRQoL in a population of patients with polypharmacy. Setting Polypharmacy patients waiting for services at a community pharmacy or hospital in Denmark. Method The original MRQoL included 14 items. It was forward-translated into Danish and backward-translated into Chinese according to a modified translation protocol proposed by Sousa and Rojjanasrirrat et al. The translation was pre-tested, adjusted, and administered to polypharmacy patients. The factor structure was examined using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Internal consistency reliability was evaluated, and criterion validity assessed using the beliefs about medicines questionnaire (BMQ) and SF-12v2. Known-group validity was carried out on age, number of medicines and setting. Main outcome measure Validity of the Danish version of the MRQoL-scale. Results 164 patients completed the questionnaire. EFA of all 14 items resulted in a two-factor structure, accounting for 72.8% of the total variance. The two factors were named "Energy/Concentration" (7 items) and "Feelings/Social" (7 items). Items correlating over 0.80 were removed leaving 11 items (Model 1). This model was further reduced to 8 items (Model 2) based on Cronbach's alpha. CFA confirmed the two-factor structure of both models. Model 2 fitted data without having to define covariations between error terms. Both factors showed high internal consistency reliability (Cronbachs' alpha 0.901-0.932). Ceiling effects were detected for both factors. Criterion validity was demonstrated via its significant correlations with SF-12vs2 subscales (Spearman's rho 0.340-0.353) and BMQ Concern (Spearman's rho - 0.451 to - 0.347). There was a statistically significant difference in relation to total scores of the MRQoL for age and number of drugs taken, indicating known-group validity. Conclusion The Danish translation of the MRQoL instrument showed measurement properties indicating a well-defined two-factor structure with high internal reliability, concurrent criterion validity, and known group validity. However, challenges remain with ceiling effects and efforts should be put into further development of the instrument.

The Strengths and Difficulties Questionnaire and standardized academic tests: Reliability across respondent type and age

Exploiting nation-wide data from the Danish National Birth Cohort, we show that children’s emotional and behavioral problems measured by the Strengths and Difficulties Questionnaire (SDQ) are closely related to their performance in standardized academic tests for reading and mathematics in sixth grade. The relationship is remarkably linear across the entire distribution for both the total difficulties score and subscale scores of the SDQ; higher scores on the SDQ (more problems) are related to worse performance in academic tests. We assess the similarity across respondent type; parent (child age 7 and 11), teacher (child age 11) and self-reported scores (child age 11), and find that teacher and parent reported scores have very similar slopes in the SDQ–test score relationship, while the child reported SDQ in relation to the academic test performance has a flatter slope.

Danish norms for the Strengths and Difficulties Questionnaire

INTRODUCTION

The Strengths and Difficulties Ques-tion-naire (SDQ) is a brief well-validated psychometric instrument for assessment of developmental, behavioural and emo-tional problems in children and adolescents. Versions of the questionnaire covering the 2-17-year age range are an-swered by parents and by pedagogues or teachers. Also, a self-report version can be used from the age of 11 years. The SDQ is well-accepted by informants and is increasingly preferred both internationally and in Denmark for research and evaluation purposes. The questionnaire is also well-suited for clinical use, especially in the primary sector. However, no comprehensive set of Danish norms has been available before this study.

METHODS

Data from an extensive survey in a Danish municipality was used to generate national norms for SDQ scores. These norms were compared with British and Nordic population data.

RESULTS

Across informants, threshold values show some variation with age and often differ between sexes. Therefore, norms are provided both with and without gender stratification. Similarities as well as differences were found between the Danish norms and materials from other countries. The differences may, to some extent, be attributable to methodological issues.

CONCLUSION

We expect that the availability of Danish SDQ norms will further stimulate the use of the instrument.

FUNDING

TrygFonden provided financial support for the development of Danish SDQ norms.

TRIAL REGISTRATION

not relevant.

Exploring correlations between neuropsychological measures and domain-specific consistency in associations with n-3 LCPUFA status in 8-9 year-old boys and girls

Long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) have in some studies been associated with cognitive and socioemotional outcomes in children, but results are inconsistent possibly due to the use of different tests and potential gender-specific effects. The objective of this cross-sectional study was to explore overall patterns in neuropsychological scores as well as correlations between scores within specific domains, and to examine potential gender differences and consistency in associations with n-3 LCPUFA status. In 199 Danish 8–9 year-old children, we performed a large battery of tests and questionnaires on attention, processing speed, executive functions, memory, and socioemotional traits, and measured erythrocyte fatty acid composition. Principal component analyses (PCA) showed that most of the variation in both cognitive performance and socioemotional traits was explained by overall performance, followed by speed-accuracy trade off and externalizing vs. internalizing problems, respectively. Boys had higher speed, lower attention and higher externalizing problem scores than girls. Measures of performance within both processing speed and attention domains correlated moderately, whereas no correlations were found for measures of executive functions apart from some weak correlations for impulsivity. Parent-rated scores for both externalizing and internalizing problems correlated strongly, whereas correlations with child-rated scores were weak. Scores within specific domains did not consistently associate with n-3 LCPUFA, except for processing speed measures which all pointed to faster processing with increased n-3 LCPUFA status. Gender differences in the associations were observed for attention and impulsivity. Child- but not parent-rated internalizing and social problems tended to associate directly with n-3 LCPUFA, supported by increased internalizing problems measured by the PCA component. In conclusion, measures of speed and attention seem to represent these domains in general, whereas single measures of more complex cognitive functions should be interpreted with caution. One approach could be to use multiple tests and create multivariate scores to guide interpretations. Furthermore, the results indicate a need to consider both parent- and child-rated socioemotional scores and gender differences in neuropsychological functions e.g. in investigations of n-3 LCPUFA effects.

Parental socioeconomic position and risk of ADHD in offspring: a cohort study of 9648 individuals in Denmark 1976-2013

The strength of the association between parental socioeconomic position (SEP) and risk of attention-deficit/hyperactivity disorder (ADHD) in offspring is found to vary substantially, perhaps due to the negligence of possible changes in parental life course SEP. The present study investigated the association between parental SEP in adulthood and risk of ADHD diagnosis in offspring and whether parental childhood SEP modified this association. The study population included 9648 live-born singletons followed in the Psychiatric Central Register from birth in 1976-1996 until 2013. Cox regression was used to estimate hazard ratios for ADHD diagnosis according to parental SEP in adulthood. The results showed that low parental SEP in adulthood was associated with higher risk of ADHD diagnosis in offspring, also after adjustment for possible confounders. Thus, offspring of parents with low SEP in adulthood had 4.52 (95% CI 2.81-7.26) times higher hazard of ADHD diagnosis compared with offspring of parents with high SEP in adulthood. Further, parental childhood SEP was found to modify the observed association. Thus, offspring of parents with downward social mobility from childhood to adulthood and offspring of parents with stable low SEP experienced the highest risk of ADHD diagnosis, followed by offspring of parents with upward social mobility, compared with offspring of parents with stable high SEP. The results suggest that it is important to take into account the possibility of social mobility as changes in parental life course SEP from childhood to adulthood seem to influence the risk of ADHD diagnosis in offspring.

Association of Education Outside the Classroom and Pupils' Psychosocial Well-Being: Results From a School Year Implementation

BACKGROUND

Education Outside the Classroom (EOtC) is a teaching method that is gaining traction, aiming to promote learning and well-being. However, research on the association between EOtC and well-being is limited.

METHODS

This quasi-experimental trial involved pupils (9-13 years) from 16 Danish public schools which implemented EOtC in some classes. Pupils (N = 511) from 27 classes were regularly exposed to EOtC (2-7 hours per week), and pupils (N = 120) from 7 parallel comparison classes were much less exposed (less than 2 hours per week). The pupils' psychosocial well-being was measured at the beginning and end of the school year using the Strengths and Difficulties Questionnaire. The results were compared between the groups.

RESULTS

Pupils regularly exposed to EOtC showed the greatest improvement in prosocial behavior. Negative associations were seen between EOtC and hyperactivity-inattention and peer problems in pupils of low socioeconomic status (SES). The observed improvements were smaller when the EOtC was spread over a larger number of sessions. Results were independent of sex.

CONCLUSIONS

Regular exposure to EOtC was found to promote social well-being, especially for pupils of low SES, and was most beneficial when concentrated in fewer, longer sessions.

Mental health among children of mothers with multiple sclerosis: A Danish cohort and register-based study

BACKGROUND

Multiple sclerosis is associated with an increased risk of developing physical, cognitive, and mental health problems. Current studies have demonstrated variating outcomes of parental multiple sclerosis mental health problems and their children's mental health development.

OBJECTIVE

The purpose of this study was to investigate whether maternal multiple sclerosis is associated with the mental health status of their child.

METHODS

Data from the Danish National Birth Cohort (DNBC) were merged with information from the Danish Multiple Sclerosis Registry. Two proxies, total difficulties score and prediction of any psychiatric diagnosis based on the strengths and difficulties questionnaire, were used to measure the mental health status of the children. The two groups were compared using Mann-Whitney and logistic regression analyses.

RESULTS

For the total difficulties score the control and exposed group consisted of respectively n = 42,016 and n = 40, and for the prediction of any psychiatric diagnosis respectively n = 16,829 and n = 17. We found no statistically significant association between maternal multiple sclerosis and mental health status on neither of the proxies.

CONCLUSION

Maternal multiple sclerosis did not show any association with the mental health status of their children at age eleven. On the contrary, other studies conclude that there is an association between maternal multiple sclerosis and the child's mental health status, one especially mediated by the maternal mental health status.

Mental health interventions among older adults: A systematic review

BACKGROUND

The aim of the present study was to conduct a systematic review to identify documented mental health promotion interventions developed and tested among population-based older adults.

METHODS

A systematic review based on PRISMA guidelines. The literature was searched in PsycINFO and PubMed between June and September 2016. The Effective Public Health Practice Project tool was used to assess the quality of the included study.

RESULTS

In total 53 randomized controlled trial studies qualified for the systematic review. Across studies, three types of common conceptual themes emerged for interventions, including: 1) individual characteristics; 2) content and structure of the interventions; and 3) implementation of the interventions.

CONCLUSIONS

No specific interventions could be recommended on the aforementioned basis. We conclude that a number of factors are of central importance for an intervention to have the desired effect. If these factors are considered, mental health can be successfully promoted among older adults.

Psychometric properties of the Danish student well-being questionnaire assessed in >250,000 student responders

BACKGROUND

Well-being is considered a prerequisite for learning. The Danish Ministry of Education initiated the development of a new 40-item student well-being questionnaire in 2014 to monitor well-being among all Danish public school students on a yearly basis. The aim of this study was to investigate the basic psychometric properties of this questionnaire.

METHODS

We used the data from the 2015 Danish student well-being survey for 268,357 students in grades 4-9 (about 85% of the study population). Descriptive statistics, exploratory factor analyses, confirmatory factor analyses and Cronbach's α reliability measures were used in the analyses.

RESULTS

The factor analyses did not unambiguously support one particular factor structure. However, based on the basic descriptive statistics, exploratory factor analyses, confirmatory factor analyses, the semantics of the individual items and Cronbach's α, we propose a four-factor structure including 27 of the 40 items originally proposed. The four scales measure school connectedness, learning self-efficacy, learning environment and classroom management. Two bullying items and two psychosomatic items should be considered separately, leaving 31 items in the questionnaire.

CONCLUSIONS

The proposed four-factor structure addresses central aspects of well-being, which, if used constructively, may support public schools' work to increase levels of student well-being.

Maternal Caffeine Consumption during Pregnancy and Behavioral Disorders in 11-Year-Old Offspring: A Danish National Birth Cohort Study

OBJECTIVE

To examine the association between maternal caffeine consumption from coffee and tea during pregnancy and offspring behavioral disorders.

STUDY DESIGN

We studied 47 491 children enrolled in the Danish National Birth Cohort between 1996 and 2002. Data on maternal coffee and tea consumption was collected at 15 and 30 weeks of gestation. When the child was 11 years old, the Strength and Difficulties Questionnaire was filled in by children, parents, and teachers. We estimated risk ratios (RRs) for offspring behavioral disorders.

RESULTS

At 15 weeks of gestation 3% and 4% of the pregnant women consumed ≥8 cups/d of coffee or tea, respectively. Maternal coffee consumption ≥8 cups/d at 15 weeks of gestation was associated with increased risk of hyperactivity-inattention disorder (RR 1.47; 95% CI 1.18-1.83), conduct-oppositional disorders (RR 1.22; 95% CI 1.01-1.48), and any psychiatric disorder (RR 1.23; 95% CI 1.08-1.40). Maternal tea consumption ≥8 cups/d at 15 weeks of gestation was associated with increased risk of anxiety-depressive disorders (RR 1.28; 95% CI 1.09-1.52) and any psychiatric disorder (RR 1.24; 95% CI 1.11-1.40). An increased risk of hyperactivity-inattention disorder was observed with increasing daily caffeine consumption at 15 weeks of gestation.

CONCLUSION

High maternal caffeine consumption from coffee and tea at 15 weeks of gestation was associated with behavioral disorders in 11-year-old offspring. We hypothesize that caffeine exposure may affect the fetal brain and program for behavioral disorders later in life. The fetal brain seems to be more sensitive to caffeine exposure at 15 weeks of pregnancy compared with 30 weeks of gestation.

Early childhood otitis media and later school performance - A prospective cohort study of associations

INTRODUCTION

Otitis media (OM) is a common disease in childhood and hearing loss (HL) is the most common complication. Prolonged HL may lead to language delay and cognitive difficulties. However, the consequences of HL due to OM are not fully understood. The aim of this study was to determine the possible association between number of OM episodes in childhood and self-rated school performance controlling for potential confounders.

METHODS

Prospectively gathered systematic interview data on OM episodes in early childhood and school performance at 11 years of age were obtained from The Danish National Birth Cohort, involving >100,000 individual pregnancies and their offspring. We defined four exposure groups (0, 1-3, 4-6 and ≥7 OM episodes) and assessed general school performance, mathematics and literacy. Possible confounders were recognized à priori and associations were determined using proportional odds regression.

RESULTS

Out of 94,745 successful pregnancies, 35,946 children without malformations and their parents completed a questionnaire at age 11 years. No associations were observed between number of OM episodes and school performance, even in children with ≥7 OM episodes.

CONCLUSION

This national birth-cohort study did not support the hypothesis that the number of OM episodes in childhood is associated with reduced self-reported school performance in children at 11 years of age.

Life Span Studies of ADHD-Conceptual Challenges and Predictors of Persistence and Outcome

There is a renewed interest in better conceptualizing trajectories of attention-deficit/hyperactivity disorder (ADHD) from childhood to adulthood, driven by an increased recognition of long-term impairment and potential persistence beyond childhood and adolescence. This review addresses the following major issues relevant to the course of ADHD in light of current evidence from longitudinal studies: (1) conceptual and methodological issues related to measurement of persistence of ADHD, (2) estimates of persistence rate from childhood to adulthood and its predictors, (3) long-term negative outcomes of childhood ADHD and their early predictors, and (4) the recently proposed new adult-onset ADHD. Estimates of persistence vary widely in the literature, and diagnostic criteria, sample characteristics, and information source are the most important factors explaining variability among studies. Evidence indicates that ADHD severity, comorbid conduct disorder and major depressive disorder, and treatment for ADHD are the main predictors of ADHD persistence from childhood to adulthood. Comorbid conduct disorder and ADHD severity in childhood are the most important predictors of adverse outcomes in adulthood among children with ADHD. Three recent population studies suggested the existence of a significant proportion of individuals who report onset of ADHD symptoms and impairments after childhood. Finally, we highlight areas for improvement to increase our understanding of ADHD across the life span.

Risk Factors of Early Otitis Media in the Danish National Birth Cohort

OBJECTIVE

To assess risk factors of otitis media (OM) in six-months-old children.

METHOD

The sample consisted of 69,105 mothers and their children from the Danish National Birth Cohort. The women were interviewed twice during pregnancy and again 6 months after birth. The outcome "one or more" maternal reported episodes of OM at age six months. In total 37 factors were assessed, covering prenatal, maternal, perinatal and postnatal factors.

RESULTS

At age six months 5.3% (95% CI 5.1-5.5) of the children had experienced one or more episodes of OM. From the regression analysis, 11 variables were associated with a risk of OM. When a Bonferroni correction was introduced, gender, prematurity, parity, maternal age, maternal self-estimated health, taking penicillin during pregnancy, and terminating breastfeeding before age six months, was associated with a risk of early OM. The adjusted ORs of OM for boys versus girls was 1.30 (95% CI 1.18-1.44). The OR having one sibling versus no siblings was 3.0 (95% CI 2.64-3.41). If the woman had been taking penicillin during pregnancy, the OR was 1.35 (95% CI 1.15-1.58). Children born before 38th gestational week had an increased OR for early OM of 1.49 (95% CI 1.21-1.82). Children of young women had an increased OR of early OM compared to children of older women. Additionally, children of women who rated their own health low compared to those rating their health as high, had an increased OR of 1.38 (95% CI 1.10-1.74). Finally, children being breastfeed less than 6 months, had an increased OR of 1.42 (95% CI 1.28-1.58) compared to children being breastfeed beyond 6 months.

CONCLUSION

These findings indicate that prenatal factors are of less importance regarding early OM before the age of six months. Postnatal risk factors seem to pose the main risk of early OM.

Associations between childhood hearing loss and behavioural and academic difficulties: A Danish cohort study

OBJECTIVE

Negative associations between hearing loss (HL) and behavioural and academic difficulties have been reported. However, most studies are based on small clinical samples. The aim of the present study was to investigate such associations using data from a large-scale non-clinical Danish birth cohort controlling for a large number of relevant confounding factors.

METHODS

The study applied data from the Aarhus Birth Cohort's 10-12-year-old follow-up (N = 7599). Associations between parent-reported HL on the one hand, and parent- and teacher-reported behavioural difficulties measured by the Strengths and Difficulties Questionnaire (SDQ) and parent-reported academic difficulties on the other hand, were investigated.

RESULTS

After controlling for relevant confounding factors, significant associations were observed between parent-reported HL and parent- and teacher-reported Externalising scores, and academic difficulties.

CONCLUSIONS

Childhood HL is associated with behavioural and academic difficulties. Parent reported HL in a non-clinical cohort is indicative for academic and behavioural difficulties.

Effects of oily fish intake on cardiovascular risk markers, cognitive function, and behavior in school-aged children: study protocol for a randomized controlled trial

BACKGROUND

Most children in Western populations do not meet recommendations for fish consumption. Oily fish is an important source of n-3 long-chain polyunsaturated fatty acids (LCPUFA), which reduce blood pressure and plasma triacylglycerol in adults and may affect cognitive development and behavior. However, to our knowledge, the potential effects of oily fish on cardiometabolic health, cognitive function, and behavior in children have not been investigated. The aim of the FiSK Junior study is to investigate the effects of oily fish consumption on cardiovascular risk markers, cognitive function, and behavior in healthy children.

METHODS/DESIGN

We are conducting a randomized controlled trial with 8- to 9-year-old Danish children, comparing the effect of consuming 300 g/week of oily fish with poultry (control) for 12 weeks between August 2016 and June 2017. The primary outcomes are blood pressure and fasting plasma triacylglycerol, which will be measured at baseline and endpoint. In addition, we will assess erythrocyte fatty acid composition (compliance), heart rate, plasma cholesterol, markers of glucose homeostasis, growth and body composition, dietary intake, and physical activity and sleep. We will also examine effects on cognitive function (attention, memory, and executive functions) by using standardized tests, behavior and emotions by administering parent-rated questionnaires and child interviews, and we will measure physiological stress response and cortisol levels. We need 150 children to complete the trial to detect a between-groups difference of 2.7 mmHg in diastolic blood pressure and 0.13 mmol/L in plasma triacylglycerol; thus, we aim to recruit 200 children. All outcomes will be analyzed in completer analysis supplemented with sensitivity analyses for the primary outcomes, and attention will be given to potential sex and genotype specificity.

DISCUSSION

The results of the FiSK Junior study are expected to fill important gaps in the current knowledge about the importance of dietary fish and n-3 LCPUFA for children's health and development, and may be used when setting dietary recommendations.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02809508 . Registered on 22 June 2016.

Associations between otitis media and child behavioural and learning difficulties: Results from a Danish cohort

OBJECTIVES

Findings from studies investigating early childhood episodes of otitis media (OM) and developmental outcomes are inconclusive. This may in part be because large-scale prospective studies controlling for relevant confounding factors are sparse. The present study investigates associations between OM in early childhood and later behavioural and learning difficulties controlling for relevant confounding factors.

METHODS

The study applied data from the Aarhus Birth Cohort's 10-12-year-old follow-up (N=7578). Associations between retrospective parent-reported OM (no OM; 1-3 episodes of OM with/without tympanostomy tubes; 4+ OM episodes without tympanostomy tubes and; 4+ OM episodes with tympanostomy tubes) one the one hand, and parent- and teacher-reported scores on the Strengths and Difficulties Questionnaire (SDQ) and parent-reported academic difficulties on the other hand, were investigated. The following variables were controlled for: parental educational level, maternal and paternal school problems, parental post-natal smoking, breastfeeding, and age at which the child started walking. All analyses were stratified by gender.

RESULTS

Large differences in background characteristics were observed for the group of children with 4+ OM episodes with tympanostomy tubes compared to the no OM group. After controlling for relevant confounders, negative associations were consistently observed for the group of children with 4+ episodes of OM with tympanostomy tubes compared to the group of children without OM. This was particularly so for girls.

CONCLUSION

The findings suggest an association between 4+ episodes of early OM with tympanostomy tubes and behavioural and learning difficulties later in childhood. The large inter-group differences, i.e. impact of residual and unmeasured confounding factors, may in part explain the observed associations and underline the need to include these in future studies.

Psychometric Properties of the Strengths and Difficulties Questionnaire and Mental Health Problems Among Children With Hearing Loss

More knowledge is needed about the characteristics of mental health problems among deaf or hard of hearing (D/HH) children. This study investigates the factor structure of one of the most widely used screening tools, the Strengths and Difficulties Questionnaire (SDQ), and the prevalence of mental health problems among D/HH children. Our data were derived from two independent samples of D/HH children, one from 2007 of children (N = 334) in bilingual/bicultural educational programs and another from 2014 of children (N = 233) in mostly mainstream oral educational programs with cochlear implants. Teacher-SDQs were collected for the 2007 sample and parent-SDQs for the 2014 sample. The factor structure of the SDQ was examined from both Exploratory Factor Analytic (EFA) and Confirmatory Factor Analytic (CFA) perspectives and internal consistency was examined. Mean problem scores were presented. The five-factor structure of the SDQ was overall found for both the 2007 and the 2014 samples using EFA. However, problems with the Conduct scale and the reversed items loading onto the Prosocial scale were observed. The five-factor model was superior to a one- and a two-factor model from a CFA perspective in both samples. Better internal consistency was observed for the 2007 sample rated by teachers. Both samples showed higher mean scores on all SDQ problem subscales compared to a cohort of Danish children without hearing loss. The five-factor structure of the SDQ is recommended to be used among D/HH children.

Is alcohol binge drinking in early and late pregnancy associated with behavioural and emotional development at age 7 years?

The purpose of this study was to investigate associations of maternal binge drinking in early and late pregnancy with child behavioural and emotional development at age seven. It was hypothesised that late exposure is associated with more negative outcomes than early exposure. Differences were expected on the continuous outcome measures, but not on above cutoff scale scores. Data were derived from the Danish National Birth Cohort. Three exposure groups were defined according to binge drinking from three interviews regarding binge episodes in early, middle and late pregnancy. A 'no binge' group included women with no binge episodes reported in any of the interviews, the 'early bingers' reported episodes in the first interview only, and the 'late bingers' in the last part of pregnancy only. The outcome measure was the Strengths and Difficulties Questionnaire (SDQ) used as continuous externalising/internalising scores and above cutoff hyperactivity/inattention, conduct, emotional and peer problems scores. Only women with full information concerning binge drinking from the three interviews, together with full-scale SDQ information on their children at age seven and being term-born, were included in the study (N = 37,315). After adjustment for maternal education, psychiatric diagnoses, age and smoking, children exposed to binge drinking in early and late pregnancy had significantly higher mean externalizing scores at age seven than unexposed children, an effect albeit much less for early binge drinking (relative change in mean 1.02, CI 1.00-1.05) than for late binge drinking (relative change in mean 1.21, CI 1.04-1.42). No associations were observed for any of the above cutoff outcomes. Exposure to binge drinking in early and late pregnancy is associated with elevated externalising scores, particularly so in late pregnancy. No increased risk for any of the above cutoff scale scores was observed.

Parental smoking during pregnancy and ADHD in children: the Danish national birth cohort

BACKGROUND

Prenatal maternal smoking has been associated with attention-deficit/hyperactivity disorder (ADHD) in children, but the causal nature of this association is still under scrutiny. We examined the association with maternal smoking and nicotine replacement use during pregnancy, using association with paternal smoking as a marker of potential genetic or social confounding.

METHODS

We included 84 803 singletons who participated in the Danish National Birth Cohort. Information on parental smoking was reported by the mothers during pregnancy. Children with ADHD were identified from the Danish Psychiatric Central Register, the Danish National Patient Register, and the Register of Medicinal Product Statistics by the International Classification of Diseases, 10th Revision diagnosis or medication. We also used hyperactivity/inattention score of the parent-reported Strengths and Difficulties Questionnaire, included in the 7-year follow-up of the National Birth Cohort.

RESULTS

Maternal and paternal smoking during pregnancy were associated with an elevated risk of ADHD defined by hospital diagnosis, medication, and hyperactivity/inattention score, but the association was stronger for maternal smoking than for paternal smoking. Compared with children born to nonsmoking mothers and smoking fathers, children born of smoking mothers and nonsmoking fathers had a higher risk of ADHD (adjusted hazard ratio = 1.26; 95% confidence interval, 1.03 to 1.53). We also saw a higher risk of ADHD in children of mothers who used nicotine replacement during pregnancy.

CONCLUSIONS

Our findings indicate that the association between prenatal maternal smoking and ADHD may overestimate a causal link, but nicotine exposure or related factors may still play a causal role.

Prenatal exposure to alcohol, and gender differences on child mental health at age seven years

BACKGROUND

It remains uncertain whether exposure to lower doses of alcohol is damaging to the developing fetus. The present study aimed to investigate associations for boys and girls between prenatal exposure to binge drinking and lower doses of alcohol in pregnancy, and parent-reported behavioural and emotional development at age seven.

METHODS

This study used data from the Danish National Birth Cohort. Associations between cumulated alcohol exposure and binge drinking from full pregnancy and parent scores on the Strengths and Difficulties Questionnaire (SDQ) measured at age seven were investigated. The SDQ was used as continuous externalising/internalising scores, and as above/below cut-off for the specific scales of hyperactivity/inattention, conduct, emotional and peer problems. Inclusion criteria were information on alcohol exposure from three interviews, SDQ scores at age seven and being born full term (n=37 152).

RESULTS

Controlling for relevant confounders, small positive associations were observed between binge drinking and internalising (relative change in mean: 1.04-1.06), externalising scores (relative change in mean: 1.01-1.07), and conduct scores (OR 1.12 to 1.23) for boys. No associations were observed with lower doses of alcohol.

CONCLUSIONS

Exposure to binge drinking is weakly associated with impaired behavioural and emotional development measured at age seven. Large differences in background characteristics were observed between the groups defined by cumulated alcohol exposure, leaving the interpretations of findings uncertain.

Drinking or not drinking in pregnancy: the multiplicity of confounding influences

AIMS

Studies investigating associations between prenatal exposure to low-moderate doses of alcohol and mental health development in childhood are inconsistent. The aim of the present study was to compare women who drink and who do not drink alcohol in pregnancy on a number of potential confounding variables, and to investigate whether any latent variables could be identified among these.

METHODS

Data were obtained from the Danish National Birth Cohort.

EXPOSURE

cumulated alcohol intake in full pregnancy (n = 63,464). The women were subdivided into intake groups 0, >0-10, >10-30, >30-90 and >90 units of alcohol in full pregnancy. Hereafter, the abstainers were subdivided into an all-time and a pregnancy-abstaining group, and the high intakers (>90) were subdivided into a high (>90-180) and a very high (>180) intake group.

OUTCOME

self-reported and register-based information on socio-demographic and lifestyle factors, and latent variables from an exploratory factor analysis.

RESULTS

Significant differences were observed between the intake groups on virtually all parameters. Significant differences were observed between the abstaining groups and the high-intake groups. The exploratory factor analyses identified a number of latent variables between the potential confounding variables.

CONCLUSION

Differences on confounding factors may in part explain the lack of consistency in the literature investigating prenatal exposure to low-moderate doses of alcohol and mental health development. It is cautiously concluded that the failure to control for these factors introduces residual and/or unmeasured confounding into the analyses, and thus masks the potential (small) effect of being exposed to low doses of alcohol in pregnancy. It is recommended that future studies control for factor scores rather than for the observed variables as is practice today.

Psychometric properties of the Danish Strength and Difficulties Questionnaire: the SDQ assessed for more than 70,000 raters in four different cohorts

BACKGROUND

The Strength and Difficulties Questionnaire (SDQ) is a brief behavioural five factor instrument developed to assess emotional and behavioural problems in children and adolescents. The aim of the current study was to evaluate the psychometric properties for parent and teacher ratings in the Danish version of SDQ for different age groups of boys and girls.

METHODS

The Danish versions of the SDQ were distributed to a total of 71,840 parent and teacher raters of 5-, 7- and 10- to 12-year-old children included in four large scale Danish cohorts. The internal reliability was assessed and exploratory factor analyses were carried out to replicate the originally proposed five factor structure. Mean scores and percentiles were examined in order to differentiate between low, medium and high levels of emotional and behavioural difficulties.

RESULTS

The original five factor structure could be substantially confirmed. The Conduct items however did not solely load on the proposed Conduct scale and the Conduct scale was further contaminated by non-conduct items. Positively worded items tended to load on the Prosocial scale. This was more so the case for teachers than for parents. Parent and teacher means and percentiles were found to be lower compared to British figures but similar to or only slightly lower than those found in the other Nordic countries. The percentiles for girls were generally lower than for boys, markedly so for the teacher hyperactivity ratings.

CONCLUSIONS

The study supports the usefulness of the SDQ as a screening tool for boys and girls across age groups and raters in the general Danish population.