Anne Mette Skovgaard

Failure to thrive: the prevalence and concurrence of anthropometric criteria in a general infant population

Background: Failure to thrive (FTT) in early childhood is associated with subsequent developmental delay and is recognised to reflect relative undernutrition. Although the concept of FTT is widely used, no consensus exists regarding a specific definition, and it is unclear to what extent different anthropometric definitions concur. Objective: To compare the prevalence and concurrence of different anthropometric criteria for FTT and test the sensitivity and positive predictive values of these in detecting children with “significant undernutrition”, defined as the combination of slow conditional weight gain and low body mass index (BMI). Methods: Seven criteria of FTT, including low weight for age, low BMI, low conditional weight gain and Waterlow’s criterion for wasting, were applied to a birth cohort of 6090 Danish infants. The criteria were compared in two age groups: 2–6 and 6–11 months of life. Results: 27% of infants met one or more criteria in at least one of the two age groups. The concurrence among the criteria was generally poor, with most children identified by only one criterion. Positive predictive values of different criteria ranged from 1% to 58%. Most single criteria identified either less than half the cases of significant undernutrition (found in 3%) or included far too many, thus having a low positive predictive value. Children with low weight for height tended to be relatively tall. Conclusions: No single measurement on its own seems to be adequate for identifying nutritional growth delay. Further longitudinal population studies are needed to investigate the discriminating power of different criteria in detecting significant undernutrition and subsequent outcomes.

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.

Pregnancy and Birth Cohort Resources in Europe: a Large Opportunity for Aetiological Child Health Research

BACKGROUND During the past 25 years, many pregnancy and birth cohorts have been established. Each cohort provides unique opportunities for examining associations of early-life exposures with child development and health. However, to fully exploit the large amount of available resources and to facilitate cross-cohort collaboration, it is necessary to have accessible information on each cohort and its individual characteristics. The aim of this work was to provide an overview of European pregnancy and birth cohorts registered in a freely accessible database located at http://www.birthcohorts.net. METHODS European pregnancy and birth cohorts initiated in 1980 or later with at least 300 mother-child pairs enrolled during pregnancy or at birth, and with postnatal data, were eligible for inclusion. Eligible cohorts were invited to provide information on the data and biological samples collected, as well as the timing of data collection. RESULTS In total, 70 cohorts were identified. Of these, 56 fulfilled the inclusion criteria encompassing a total of more than 500,000 live-born European children. The cohorts represented 19 countries with the majority of cohorts located in Northern and Western Europe. Some cohorts were general with multiple aims, whilst others focused on specific health or exposure-related research questions. CONCLUSION This work demonstrates a great potential for cross-cohort collaboration addressing important aspects of child health. The web site, http://www.birthcohorts.net, proved to be a useful tool for accessing information on European pregnancy and birth cohorts and their characteristics.

Assessment and classification of psychopathology in epidemiological research of children 0–3 years of age

The research of psychopathology in children 0–3 years of age is dominated by clinical case studies and theoretical reflections, and epidemiological studies are few. This paper reviews methods to assess and classify psychopathology in children 0–3 years old in an epidemiological context. Diagnostic assessments of children 0–3 years of age are based on information from different sources and investigation of several domains of mental functioning, and the rapid developmental changes and the relationship context are taken into account. The reviewed literature shows a range of methods to assess and classify psychopathology in children 0–3 years of age: screening instruments with established psychometric properties, such as the Child Behaviour Checklist (CBCL) and the Checklist for Autism in Toddlers (CHAT), and methods of in-depth assessment known from both clinical practice and research: developmental tests, such as the Bayley Scales, and relationship assessments, such as the Early Relational Assessment (ERA). The classification of psychopathology in young children can be approved by the Diagnostic Classification 0–3. The reliability and validity of DC 0–3 have not yet been established, but preliminary results seem promising. The demands made on diagnostic assessment procedures in epidemiological research of children 0–3 years of age can be met by a combination of well-established research instruments, such as the CBCL, with in-depth clinical assessment procedures, such as the Bayley Scales and the ERA, and diagnostic classification by DC 0–3.

The Copenhagen County child cohort: Design of a longitudinal study of child mental health

Background: Epidemiological studies of psychopathology in the first years of life are few, and the association between mental health problems in infancy and psychiatric disturbances later in life has not been systematically investigated. The aim of the present project was to study mental health problems and possibilities of intervention from infancy and onward. Methods: The basic study population consists of a birth cohort of 6,090 children born in the year 2000 in the County of Copenhagen, the Copenhagen County Child Cohort, CCCC 2000. At stage one CCCC 2000 was established on data from the Civil Registration System, Danish national registers, and standardized, longitudinal data from the first year of living obtained by public health nurses. At stage two a subsample was assessed at 1½ years of age concerning child psychiatric illness and associated factors in a case-control study nested in the cohort, including a random sample. Participation rate at stage one was 92%. Perspectives: Ongoing studies of CCCC 2000 include studies of failure to thrive, register studies, and studies of the predictive validity of public health screening. A follow-up study concerning the prevalence of psychopathology at age 5 is planned. Summary: The Copenhagen County Child Cohort CCCC 2000 is a longitudinal study of mental health from infancy investigating psychopathology in early childhood. Results from this study will add to the knowledge of risk factors and course of mental health problems in childhood and contribute to the validation of the mental health screening made by public health nurses.

Eating patterns in a population-based sample of children aged 5 to 7 years: association with psychopathology and parentally perceived impairment.

Objective: There is still a lack of research on childhood eating patterns and their correlates in relation to psychopathology and parentally perceived impact in general population samples. We aimed to determine which eating patterns were more likely to be identified as problematic by parents, and their impact and association with childhood psychopathology (emotional, behavioral, and pervasive developmental disorders) in a general population child cohort. Methods: We collected data as part of the 5- to 7-year-old follow-up of a randomly derived subsample of the Copenhagen Child Cohort 2000. Of the eligible 2912, 1327 (45.6%) children and parents participated in the study. Parents were interviewed using a composite instrument assessing eating behaviors and their impact. Associations with contemporaneous psychopathology were determined using logistic regression. Results: Five eating patterns were identified (good eating/overeating, picky eating, slow/poor eating, delayed eating behaviors, and snacking behaviors); among these, picky eating and slow/poor eating were described as a problem by more than half of parents and they also had high impact. Picky eating was associated with psychopathology across disorders. Emotional undereating was associated with emotional and functional somatic symptoms. A quarter of parents described at least one eating behavior as a problem. Conclusions: Eating behaviors in a general population cohort were differentially associated with impact and psychopathology. Picky eating was highlighted among other behaviors as having negative correlates. Better knowledge of how childhood eating behaviors impact on children and their association with psychopathology will aid adequate assessment and treatment.

A Confirmatory Approach to Examining the Factor Structure of the Strengths and Difficulties Questionnaire (SDQ): A Large Scale Cohort Study

The aim of this study was to examine the factor structure of the Strengths and Difficulties Questionnaire (SDQ) using a Structural Confirmatory Factor Analytic approach. The Danish translation of the SDQ was distributed to 71,840 parents and teachers of 5–7 and 10–12-year-old boys and girls from four large scale cohorts. Three theoretical models were examined: 1. a model with five first order factors (i.e., hyperactivity/inattention, conduct, emotional, peer problems and prosocial), 2. a model adding two internalising and externalising second order factors to model 1, and 3. a model adding a total difficulties second order factor to model 1. Model fits were evaluated, multi-group analyses were carried out and average variance extracted (AVE) and composite reliability (CR) estimates were examined. In this general population sample, low risk sample models 1 and 2 showed similar good overall fits. Best model fits were found when two positively worded items were allowed to cross load with the prosocial scale, and cross loadings were allowed for among three sets of indicators. The analyses also revealed that model fits were slightly better for teachers than for parents and better for older children than for younger children. No convincing differences were found between boys and girls. Factor loadings were acceptable for all groups, especially for older children rated by teachers. Some emotional, peer, conduct and prosocial subscale problems were revealed for younger children rated by parents. The analyses revealed more internal consistency for older children rated by teachers than for younger children rated by parents. It is recommended that model 1 comprising five first order factors, or alternatively model 2 with additionally two internalising/externalising second order factors, should be used when employing the SDQ in low risk epidemiological samples.

Psychotic experiences co-occur with sleep problems, negative affect and mental disorders in preadolescence.

BACKGROUND Knowledge on the significance of childhood psychotic symptoms and experiences (PE) is still limited. This study aimed to investigate the prevalence and clinical significance of PE in preadolescent children from the general population by use of in-depth psychopathological interviews and comprehensive diagnostic assessments. METHODS We investigated 1,632 children from the general population-based Copenhagen Child Cohort 2000. PE were measured by semistructured interviews using the K-SADS-PL-items on psychotic and affective symptoms, each symptom scored as not present versus likely or definitely present. The Development and Well-Being Assessment (DAWBA) was used independently to diagnose DSM-IV-mental disorders. Puberty development and sleep disturbance were self-reported. The associations between PE (any lifetime hallucination and/or delusion) and various mental problems and disorders were examined by multivariable binomial regression analyses, adjusting for gender and onset of puberty. RESULTS The weighted life time prevalence of PE at age 11-12 years was 10.9% (CI 9.1-12.7). The majority of children with PE (n = 172) either had a diagnosable DSM-IV-mental disorder (31.4%) or self-reported mental health difficulties in absence of a diagnosis (31.4%). The risk of delusions increased with onset of puberty. The risk of PE increased with emotional and neurodevelopmental disorders, subthreshold depressive symptoms, sleep problems and lack of sleep, regardless of whether PE were expressed as hallucinations and/or delusions. The highest correlations were seen for emotional and multiple disorders. CONCLUSIONS Psychotic experiences are particularly prevalent in the context of affective dysregulation and sleep disturbance, increase with onset of puberty and represent a trans-diagnostic marker of psychopathology.

Hyper-Theory-of-Mind in Children with Psychotic Experiences

Background Alterations in Theory-of-Mind (ToM) are associated with psychotic disorder. In addition, studies in children have documented that alterations in ToM are associated with Psychotic Experiences (PE). Our aim was to examine associations between an exaggerated type of ToM (HyperToM) and PE in children. Children with this type of alteration in ToM infer mental states when none are obviously suggested, and predict behaviour on the basis of these erroneous beliefs. Individuals with HyperToM do not appear to have a conceptual deficit (i.e. lack of representational abilities), but rather they apply their theory of the minds of others in an incorrect or biased way. Method Hypotheses were tested in two studies with two independent samples: (i) a general population sample of 1630 Danish children aged 11–12 years, (ii) a population-based sample of 259 Dutch children aged 12–13 years, pertaining to a case-control sampling frame of children with auditory verbal hallucinations. Multinomial regression analyses were carried out to investigate the associations between PE and ToM and HyperToM respectively. Analyses were adjusted for gender and proxy measures of general intelligence. Results Low ToM score was significantly associated with PE in sample I (OR = 1.6 95%CI 1.1–2.3 χ2(4) = 12.42 p = 0.010), but not in sample II (OR = 0.9 95%CI 0.5–1.8 χ2(3) = 7.13 p = 0.816). HyperToM was significantly associated with PE both in sample I (OR = 1.8, 95%CI 1.2–2.7 χ2(3) = 10.11 p = 0.006) and II (OR = 4.6, 95%CI 1.3–16.2 χ2(2) = 7.56 p = 0.018). HyperToM was associated particularly with paranoid delusions in both sample I (OR = 2.0, 95%CI: 1.1–3.7% χ2(4) = 9.93 p = 0.021) and II (OR = 6.2 95%CI: 1.7–23.6% χ2(4) = 9.90 p = 0.044). Conclusion Specific alterations in ToM may be associated with specific types of psychotic experiences. HyperToM may index risk for developing psychosis and paranoid delusions in particular.

Infant behaviors are predictive of functional somatic symptoms at ages 5-7 years: results from the Copenhagen Child Cohort CCC2000.

OBJECTIVE To investigate infancy predictors of impairing functional somatic symptoms (FSS) at child ages 5-7 years with a focus on problems with feeding, sleep, and tactile reactivity. STUDY DESIGN This study is part of a longitudinal birth cohort study, Copenhagen Child Cohort CCC2000. Child health, development, and functioning were assessed by community health nurses at 4 home visits from birth to age 10 months. FSS at ages 5-7 years were measured by the Soma Assessment Interview in 1327 children. Sociodemographic data and information on maternal psychiatric illness were obtained from the Danish National Registers. RESULTS Multiple logistic regression analysis controlled for maternal psychiatric illness and annual household income revealed that combined infancy regulatory problems (ie, at least 2 of 3 problems of feeding, sleeping, or tactile reactivity during the first 10 months of living) predicted impairing FSS at 5-7 years (aOR = 2.9, 95% CI: 1.3-6.6). Maternal psychiatric illness during the childs first year of living was also associated with later child FSS (aOR = 7.1, 95% CI: 1.8-27.8). CONCLUSION Regulatory problems may be an early marker of disturbed sensory reactivity in young children, which together with maternal psychiatric problems, point to possible early risk mechanisms of impairing FSS in childhood.