ALSPAC--the Avon Longitudinal Study of Parents and Children. I. Study methodology

ALSPAC (The Avon Longitudinal Study of Parents and Children, formerly the Avon Longitudinal Study of Pregnancy and Childhood) was specifically designed to determine ways in which the individual's genotype combines with environmental pressures to influence health and development. To date, there are comprehensive data on approximately 10,000 children and their parents, from early pregnancy until the children are aged between 8 and 9. The study aims to continue to collect detailed data on the children as they go through puberty noting, in particular, changes in anthropometry, attitudes and behaviour, fitness and other cardiovascular risk factors, bone mineralisation, allergic symptoms and mental health. The study started early during pregnancy and collected very detailed data from the mother and her partner before the child was born. This not only provided accurate data on concurrent features, especially medication, symptoms, diet and lifestyle, attitudes and behaviour, social and environmental features, but was unbiased by parental knowledge of any problems that the child might develop. From the time of the child's birth many different aspects of the child's environment have been monitored and a wide range of phenotypic data collected. By virtue of being based in one geographic area, linkage to medical and educational records is relatively simple, and hands-on assessments of children and parents using local facilities has the advantage of high quality control. The comprehensiveness of the ALSPAC approach with a total population sample unselected by disease status, and the availability of parental genotypes, provides an adequate sample for statistical analysis and for avoiding spurious results. The study has an open policy in regard to collaboration within strict confidentiality rules.     

Sources of Vitamin A in the Diets of Pre-School Children in the Avon Longitudinal Study of Parents and Children (ALSPAC)

Vitamin A is essential for growth and development. We investigated whether high consumption of energy-dense nutrient-poor foods in the diets of pre-school children is detrimental to diet quality with respect to vitamin A. Data were collected from 755 children at 18-months and 3½-years, from the Avon Longitudinal Study of Parents and Children, using 3-day unweighed dietary records completed by parents in 1994 and 1996, respectively. Energy, carotene and retinol intakes were calculated. The quality of the diet declined from 18-months to 3½-years with respect to vitamin A. Preformed retinol intakes decreased by −54 μg/day on average (p = 0.003). Carotene intakes were similar at each age although there was a 23% increase in energy intake by 3½-years. Longitudinally those in the highest quartile of intake at 18-months were twice as likely to remain in the highest quartile at 3½-years for retinol (OR 2.21 (95% CI 1.48–3.28)) and carotene (OR 1.66 (95% CI 1.11–2.50)) than to change quartiles. Nutrient-rich core foods provided decreasing amounts of carotene and preformed retinol over time (both p < 0.001). Vegetables and milk contributed the highest proportion of carotene at both ages, but milk’s contribution decreased over time. Milk and liver were the largest sources of retinol. Nutrient-poor foods provided an increased proportion of energy (p < 0.001) with low proportions of both nutrients; however fat spreads made an important contribution. It is recommended that pre-school children should take vitamin supplements; only 19% at 18-months did this, falling to 11% at 3½-years. Care should be taken to choose nutrient-rich foods and avoid energy-dense, nutrient-poor foods when feeding pre-school children.     

The Speech and Language of Children Aged 25 Months: Descriptive Data from the Avon Longitudinal Study of Parents and Children

A major epidemiological study, the Avon Longitudinal Study of Parents and Children, has provided the opportunity for a population study of children's speech and language. Data collected via direct assessments and maternal self-completion questionnaire on 1127 children aged 25 months is presented in this paper. The speech and language of the children shows great range in terms of the stage of expressive language development achieved, with some children already accomplished talkers and others only just entering the world of words As in other studies, girls showed more advanced skills than boys. A clear pattern emerges regarding the children's use of sound classes with errors in postvocalic sounds reducing first, followed by velars, fricatives, liquids and finally, consonant clusters. Associations were found between the children's verbal comprehension and their reported expressive stage, pretend play, turn taking in games, imitation of words and sounds and singing of nursery rhymes.     

The Speech and Language of Children Aged 25 Months: Descriptive Data from the Avon Longitudinal Study of Parents and Children

A major epidemiological study, the Avon Longitudinal Study of Parents and Children, has provided the opportunity for a population study of children's speech and language. Data collected via direct assessments and maternal self-completion questionnaire on 1127 children aged 25 months is presented in this paper. The speech and language of the children shows great range in terms of the stage of expressive language development achieved, with some children already accomplished talkers and others only just entering the world of words As in other studies, girls showed more advanced skills than boys. A clear pattern emerges regarding the children's use of sound classes with errors in postvocalic sounds reducing first, followed by velars, fricatives, liquids and finally, consonant clusters. Associations were found between the children's verbal comprehension and their reported expressive stage, pretend play, turn taking in games, imitation of words and sounds and singing of nursery rhymes.     

Identifying failure to thrive in the long term care setting

INTRODUCTION AND RATIONALE: Geriatric failure to thrive (GFTT) is commonly encountered in the long term care (LTC) setting. This syndrome of unexplained functional decline can be approached in a methodical manner. The updated Minimum Data Set (MDS) 3.0, now implemented in almost all skilled nursing facilities, includes pertinent clinical information that could be used to identify residents who manifest GFTT. A screening tool using data from the MDS 3.0 could be used by LTC providers to evaluate LTC residents. METHODS: A literature review was completed to identify articles focused on (1) GFTT in the LTC setting and (2) tools to identify GFTT. Common components of GFTT were matched with items collected as part of the MDS 3.0 with a goal to determine its utility as a screening tool to identify GFTT in the LTC setting. OUTCOMES AND DISCUSSION: The MDS 3.0 includes assessment of numerous components commonly observed in patients with GFTT. By using clinically validated tools, the MDS 3.0 may assist in the recognition of LTC residents with or at risk for GFTT. Once GFTT is recognized, the LTC interdisciplinary team can then identify potentially reversible causes, set goals of care, and develop a comprehensive care plan that may include diagnostic measures, curative interventions, and/or palliative measures individualized to the resident.     

Resolving the feeding difficulties associated with non-organic failure to thrive

Summary Since 1991 The Children's Society's Infant Support Project has been working in Wiltshire with the families of under 3 year olds identified as failing to thrive non-organically. Research has shown that the only common factor in children with this problem is the presence of feeding difficulties. The service concentrates on helping parents/caregivers to resolve the problems which are allowing the difficulties to continue. The multidisciplinary staff team work on a domiciliary basis, using working practices founded on social learning theory. A recent evaluation indicated that for more than two-thirds of the children with whom the project had worked, a satisfactory or very satisfactory outcome was achieved. Funding for the service is received from the Health Commission for Wiltshire and Bath, Wiltshire Social Services Department and the Children's Society.     

Social work intervention and failure to thrive in infants and children

Failure to thrive (FTT) is a diagnostic term used to describe infants and children who fail to grow and develop at a normal rate. There has been limited literature focused on the role social workers play in working with children who fail to thrive. Because the focus of the current health care system is on using an interdisciplinary team approach, it is crucial that social workers make a place for themselves on treatment teams and continue to use their skills to provide comprehensive treatment. This article educates social workers about FTT and addresses the roles social workers have in the treatment of children who fail to thrive and how their services provide a therapeutic and team-oriented approach.     

Associations of birth size and duration of breast feeding with cardiorespiratory fitness in childhood: findings from the Avon Longitudinal Study of Parents and Children (ALSPAC)

OBJECTIVES: To explore the developmental origins of cardiorespiratory fitness. METHODS: We examined the associations of birth size and duration of breast feeding with cardiorespiratory fitness assessed at the 9 year follow-up examination in 3612 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC). We used physical work capacity at a heart rate of 170 beats per minute (PWC(170)) as our assessment of cardiorespiratory fitness. This was estimated using standard regression methods from parameters measured using an electronically braked cycle ergometer. RESULTS: Birth weight, length and ponderal index were all positively associated with cardiorespiratory fitness in both sexes, with no strong evidence of a difference in effect between girls and boys. Work capacity increased by 1.12 W (95% CI: 0.83, 1.40) on average per 1 standard deviation (SD) greater birth weight. This association was not affected by adjustment for socioeconomic position and maternal smoking during pregnancy; there was some attenuation with adjustment for both maternal and paternal height and body mass index and more marked attenuation with adjustment for the child's height and body mass index. In the fully adjusted model work capacity increased by 0.51 W (95% CI: 0.21, 0.81) per SD birth weight. Whether an individual had been breastfed and duration of breastfeeding were not associated with cardiorespiratory fitness in any models. CONCLUSION: Our results provide some support for a role of intrauterine factors in determining cardiorespiratory fitness in childhood.     

The prevalence of symptoms and consultations in pre-school children in the Avon Longitudinal Study of Parents and Children (ALSPAC): a prospective cohort study

BACKGROUND: Pre-school children are frequent users of health services, but little contemporary data are available describing their symptoms or why they consult. OBJECTIVE: To describe symptom and consultation prevalence in pre-school children and to identify the socio-demographic factor or factors associated with consultations for those symptoms. METHODS: Prospective cohort study of 13,617 pre-school children living in south-west England. Parents completed questionnaires asking about symptoms and consultations for those symptoms at six, 18, 30, 42 and 57 months. RESULTS: During the pre-school years, all children experienced one or more symptoms, most commonly cold, cough, high temperature, vomiting or diarrhoea. Ninety seven percent consulted a doctor at least once, most commonly for cough, high fever and/or earache. Lower parity was most strongly and consistently associated with higher consultation rates. CONCLUSIONS: Fever, respiratory and gastro-intestinal symptoms are a normal part of pre-school life. Research of acute conditions in young children could focus on the most common symptoms leading to consultation, namely cough, fever and earache. Efforts to support parents' help seeking decision making might usefully be targeted at first time parents.     

Use of energy-dense formula for treating infants with non-organic failure to thrive

OBJECTIVE: To evaluate if simply increasing the energy density of the formula will lead to increased energy intake and weight gain in infants with non-organic failure to thrive. DESIGN: In this hospital-based trial, 15 infants (mean age, 7.6+/-1.4 months) with non-organic failure to thrive were fed a regular strength formula (2.8 kJ/ml) for 3 days and then switched to the same formula with a higher energy density (4.18 kJ/ml) for 3 days after a 2 day 'wash-out' period. Daily nude weights and energy intakes were recorded for the two 3 day periods. RESULTS: During feeding with the higher density formula, nine (60%) infants had a significant increase in their energy intake and weight gain (both P<0.02); four (27%) showed no change in energy intake and self-regulated their intake by decreasing the volume of feeds consumed to maintain energy intake; and two (13%) infants consumed a significantly reduced amount of energy (P<0.02). CONCLUSION: Increasing the energy density of the formula may provide a useful intervention to increase the weight gain and energy intake of most infants with non-organic failure to thrive.     

The effect of maternal smoking status,educational level and age on food and nutrient intakes in preschool children: results from the Avon Longitudinal Study of Parents and Children

OBJECTIVE: Studies in adults have demonstrated that smoking status is associated with dietary quality, with smokers tending to have diets that conform less closely to guidelines on healthy eating than nonsmokers. However, there is very little information on the relation between children's dietary quality and parental smoking status. The objective of this study was to investigate the relation between maternal smoking status and nutrient intake in preschool children, allowing for the possible confounding effects of maternal educational level and age at delivery. SUBJECTS: In total, 993 children aged 18 months participating in the Avon Longitudinal Study of Parents and Children. METHODS: Diet was assessed by a 3-day food record. Maternal smoking status and educational level and age at delivery were assessed by questionnaire. RESULTS: In multivariate analysis, the children of smokers had significantly higher intakes of monounsaturated fatty acids and starch, and lower intakes of nonstarch polysaccharides (NSP). They were also less likely to have eaten poultry, buns, cakes and puddings, wholemeal bread and fruit, and more likely to have drunk sugar-sweetened soft drinks. Intakes of NSP and most vitamins and minerals increased significantly with increasing maternal education. Children of more highly educated mothers were less likely to have eaten chocolate, crisps and white bread, and more likely to have consumed wholemeal bread, fruit and fruit juice. CONCLUSIONS: The children of nonsmokers and more highly educated mothers consumed a diet that conformed more closely to current guidelines on healthy eating. These dietary differences may contribute to the excess of ill-health observed in the children of smokers and of less-educated mothers.     

Differences between infants and adults in the social aetiology of wheeze. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

OBJECTIVES: To compare the relation between relative deprivation, its associated social risk factors and the prevalence of wheeze in infancy and in adulthood. DESIGN: A cross sectional population study. SETTING: The three District Health Authorities of Bristol. SUBJECTS: A random sample of 1954 women stratified by age and housing tenure to be representative of women with children < 1 in Great Britain and selected from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC). MAIN OUTCOME MEASURES: The prevalence of wheeze for infants at six months after birth and for their mothers and fathers at eight months postpartum. Potential mediators of the relation between relative deprivation and wheeze measured were overcrowded living conditions, number of other siblings in the household, damp or mouldy housing conditions, maternal and paternal smoking behaviour, and infant feeding practice. RESULTS: 63.4% (1239) of the sample lived in owner occupied/mortgaged accommodation (relatively affluent) and 36.6% (715) lived in council house/rented accommodation (relatively deprived). Wheeze was significantly more likely for infants living in council house/rented accommodation (chi 2 = 15.93, df = 1, p < 0.0001), their mothers (chi 2 = 9.28, df = 1, p < 0.001) and their fathers (chi 2 = 7.41, df = 1, p < 0.01). For those living in council house/rented accommodation backward stepwise logistic regression analyses showed that infants with other siblings in the household were significantly more likely to wheeze (OR = 1.83, 95% CI = 1.27, 2.65), as were infants whose mothers smoked (OR = 1.82, 95% CI = 1.30, 2.55) and those who were breast fed for less than three months (OR = 0.66, 95% CI = 0.44, 0.98). Mothers with a partner who smoked were significantly more likely to report wheeze (OR = 1.73, 95% CI = 1.05, 2.85). There was no independent association between the social factors included in the analysis and the likelihood of wheeze for fathers. CONCLUSIONS: This study identified differences in the social factors associated with a higher prevalence of wheeze in infancy and in adulthood; results suggested that this symptom was commonly linked to infection in infancy, but not in adulthood. While environmental tobacco smoke was associated with a higher prevalence of wheeze in infancy and in adulthood, this does not necessarily indicate a common underlying mechanism; possible explanations are discussed.