Melissa Wake

Prevalence of challenge-proven IgE-mediated food allergy using population-based sampling and predetermined challenge criteria in infants

BACKGROUND Several indicators suggest that food allergy in infants is common and possibly increasing. Few studies have used oral food challenge to measure this phenomenon at the population level. OBJECTIVE To measure the prevalence of common IgE-mediated childhood food allergies in a population-based sample of 12-month-old infants by using predetermined food challenge criteria to measure outcomes. METHODS A sampling frame was used to select recruitment areas to attain a representative population base. Recruitment occurred at childhood immunization sessions in Melbourne, Australia. Infants underwent skin prick testing, and those with any sensitization (wheal size ≥ 1 mm) to 1 or more foods (raw egg, peanut, sesame, shellfish, or cows milk) were invited to attend an allergy research clinic. Those who registered a wheal size ≥ 1 mm to raw egg, peanut, or sesame underwent oral food challenge. RESULTS Amongst 2848 infants (73% participation rate), the prevalence of any sensitization to peanut was 8.9% (95% CI, 7.9-10.0); raw egg white, 16.5% (95% CI, 15.1-17.9); sesame, 2.5% (95% CI, 2.0-3.1); cows milk, 5.6% (95% CI, 3.2-8.0); and shellfish, 0.9% (95% CI, 0.6-1.5). The prevalence of challenge-proven peanut allergy was 3.0% (95% CI, 2.4-3.8); raw egg allergy, 8.9% (95% CI, 7.8-10.0); and sesame allergy, 0.8% (95% CI, 0.5-1.1). Oral food challenges to cows milk and shellfish were not performed. Of those with raw egg allergy, 80.3% could tolerate baked egg. CONCLUSION More than 10% of 1-year-old infants had challenge-proven IgE-mediated food allergy to one of the common allergenic foods of infancy. The high prevalence of allergic disease in Australia requires further investigation and may be related to modifiable environmental factors.

Randomised controlled trial of behavioural infant sleep intervention to improve infant sleep and maternal mood

Abstract Objective: To compare the effect of a behavioural sleep intervention with written information about normal sleep on infant sleep problems and maternal depression. Design: Randomised controlled trial. Setting: Well child clinics, Melbourne, Australia Participants: 156 mothers of infants aged 6-12 months with severe sleep problems according to the parents. Main outcome measures: Maternal report of infant sleep problem; scores on Edinburgh postnatal depression scale at two and four months. Intervention: Discussion on behavioural infant sleep intervention (controlled crying) delivered over three consultations. Results: At two months more sleep problems had resolved in the intervention group than in the control group (53/76 v 36/76, P=0.005). Overall depression scores fell further in the intervention group than in the control group (mean change 3.7, 95% confidence interval 4.7 to 2.7, v 2.5, 1.7 to 3.4, P=0.06). For the subgroup of mothers with depression scores of 10 and over more sleep problems had resolved in the intervention group than in the control group (26/33 v 13/33, P=0.001). In this subgroup depression scores also fell further for intervention mothers than control mothers at two months (6.0, 7.5 to 4.0, v 3.7, 4.9 to 2.6, P=0.01) and at four months (6.5, 7.9 to 5.1 v −4.2, −5.9 to 2.5, P=0.04). By four months, changes in sleep problems and depression scores were similar. Conclusions: Behavioural intervention significantly reduces infant sleep problems at two but not four months. Maternal report of symptoms of depression decreased significantly at two months, and this was sustained at four months for mothers with high depression scores. What is already known on this topic Infant sleep problems and postnatal depression are both common potentially serious problems Women whose infants have sleep problems are more likely to report symptoms of depression Uncontrolled studies in clinical populations suggest that reducing infant sleep problems improves postnatal depression, but there is no good quality evidence in the community for such effectiveness What this study adds A brief community based sleep intervention based on teaching the controlled crying method effectively decreased infant sleep problems and symptoms of maternal depression, particularly for “depressed” mothers The intervention was acceptable to mothers and reduced the need for other sources of help

Prevalence, stability, and outcomes of cry-fuss and sleep problems in the first 2 years of life: prospective community-based study.

OBJECTIVE. To report the prevalence and stability of cry-fuss problems during the first 4 months of life and sleep problems from 2 to 24 months and relationships between the persistence of cry-fuss and sleep problems and outcomes at 24 months. METHODS. The study was a prospective cohort study in maternal and child health centers in 3 local government areas in Melbourne, Australia. A total of 483 first-born infants were monitored prospectively from 2 weeks through 2, 4, 8, 12, 18, and 24 months. Child behavior, maternal depression, parenting stress, and marital quality were assessed. Predictor variables were parent reports of moderate or greater cry-fuss problems (2 and 4 months) and sleep problems (8, 12, 18, and 24 months) and parent-reported, 24-hour, sleep/cry-fuss diaries (2, 4, and 12 months). RESULTS. The response rate was 68% (483 of 710 infants); the attrition rate was <6%. The prevalence of cry-fuss problems decreased from 19.1% at 2 months to 12.8% at 4 months, with 5.6% of mothers reporting cry-fuss problems at both ages. Prevalence rates of sleep problems were 21.2%, 16.2%, 10.0%, and 12.1% at 8, 12, 18, and 24 months, respectively; 6.4% had a problem at ≥3 of these ages. In multivariate analyses, cry-fuss/sleep problems at ≥3 previous time points (but not 1 or 2 time points) contributed significantly to depression (2.8% of variance), total behavior (1.4% of variance), and total stress (4.6% of variance) scores. Repeated problems had a greater impact than a concurrent sleep problem on depression and stress scores, whereas the reverse was true for behavior scores. CONCLUSIONS. Most cry-fuss and sleep problems in the first 2 years of life are transient. Persistent, rather than transient, problems contribute to maternal depression, parenting stress, and subsequent child behavior problems.

The epidemiology of overweight and obesity among Australian children and adolescents, 1995‐97

Objectives: To determine the population prevalence of overweight and obesity among Australian children and adolescents, based on measured body mass index (BMI). To determine if overweight and obesity are distributed differentially across the population of young Australians.

Outcomes and costs of primary care surveillance and intervention for overweight or obese children: the LEAP 2 randomised controlled trial

Objective To determine whether ascertainment of childhood obesity by surveillance followed by structured secondary prevention in primary care improved outcomes in overweight or mildly obese children. Design Randomised controlled trial nested within a baseline cross sectional survey of body mass index (BMI). Randomisation and outcomes measurement, but not participants, were blinded to group assignment. Setting 45 family practices (66 general practitioners) in Melbourne, Australia. Participants 3958 children visiting their general practitioner in May 2005-July 2006 were surveyed for BMI. Of these, 258 children aged 5 years 0 months up to their 10th birthday who were overweight or obese by International Obesity Taskforce criteria were randomised to intervention (n=139) or control (n=119) groups. Children who were very obese (UK BMI z score ≥3.0) were excluded. Intervention Four standard consultations over 12 weeks targeting change in nutrition, physical activity, and sedentary behaviour, supported by purpose designed family materials. Main outcomes measures Primary measure was BMI at 6 and 12 months after randomisation. Secondary measures were mean activity count/min by 7-day accelerometry, nutrition score from 4-day abbreviated food frequency diary, and child health related quality of life. Differences were adjusted for socioeconomic status, age, sex, and baseline BMI. Results Of 781 eligible children, 258 (33%) entered the trial; attrition was 3.1% at 6 months and 6.2% at 12 months. Adjusted mean differences (intervention − control) at 6 and 12 months were, for BMI, −0.12 (95% CI −0.40 to 0.15, P=0.4) and −0.11 (−0.45 to 0.22, P=0.5); for physical activity in counts/min, 24 (−4 to 52, P=0.09) and 11 (−26 to 49, P=0.6); and, for nutrition score, 0.2 (−0.03 to 0.4, P=0.1) and 0.1 (−0.1 to 0.4, P=0.2). There was no evidence of harm to the child. Costs to the healthcare system were significantly higher in the intervention arm. Conclusions Primary care screening followed by brief counselling did not improve BMI, physical activity, or nutrition in overweight or mildly obese 5-10 year olds, and it would be very costly if universally implemented. These findings are at odds with national policies in countries including the US, UK, and Australia. Trial registration ISRCTN 52511065 (www.isrctn.org)

Overweight, obesity and girth of Australian preschoolers: prevalence and socio-economic correlates

Objective:(1) To determine the prevalence of overweight and obesity in Australian 4–5-year-old children. (2) To investigate associations between socio-economic characteristics and (a) overweight/obesity and (b) waist circumference.Design:Cross-sectional population survey.Setting:Wave 1 (2004) of the Longitudinal Study of Australian Children.Participants:Nationally representative sample of 4983 4–5-year-old children (2537 boys and 2446 girls; mean age 56.9 months (s.d. 2.64 months; range 51–67 months)).Main outcome measures:Prevalence of overweight and obesity (International Obesity TaskForce definitions) and waist circumference (cm).Analysis:Prevalence estimates were obtained as weighted percentages. Uni- and multivariable ordinal logistic regression (using the proportional odds model) were used to assess associations between potential predictors and the risk of higher child body mass index status and a multivariable linear regression model to assess relationships between the same potential predictors and waist circumference.Results:15.2% of Australian preschoolers are estimated to be overweight and 5.5% obese. In univariate analyses, seven of the 12 variables were associated with higher odds of being in a heavier body mass index category. In a multivariable regression model, speaking a language other than English (particularly for boys), indigenous status and lower disadvantage quintile were the clearest independent predictors of higher body mass index status, with children in the lowest quintile of social disadvantage having 47% higher odds (95% CI 14, 92%) of being in a heavier body mass index category compared to those in the highest quintile. Waist circumference was not related to any socio-economic variable.Conclusions:This nationally representative survey confirms high rates of overweight and obesity in preschoolers throughout Australia. The recent emergence of a substantial socio-economic gradient should bring new urgency to public health measures to combat the obesity epidemic.

Parent-reported health status of overweight and obese Australian primary school children : A cross-sectional population survey

Introduction: Childhood overweight/obesity is associated with poor physical and psychosocial health in clinical samples. However, there is little information on the health status of overweight and obese children in the community, who now represent a large proportion of the child population. We examined parent-reported child health and well-being and parent concern about child weight by body mass index (BMI) category in a population sample of primary school children.Design: A stratified two-stage random cluster sample of 24 primary schools representative of the state of Victoria, Australia.Measures: BMI (weight/height2) transformed to normalised Z-scores using the 1990 UK Growth Reference; the Child Health Questionnaire (CHQ), a 13-scale 50-item parent-completed measure of health and well-being; parent self-reported height and weight; parent concern about childs weight.Results: Data were available for 2863 children aged 5–13 y (50.5% male), of whom 17% were overweight and 5.7% obese. Using logistic regression analyses with ‘normal weight’ as the referent category, obese boys were at greater risk of poor health (ie <15th centile) on seven of the 12 CHQ scales: Physical Functioning (odds ratio (OR) 2.8), Bodily Pain (OR 1.8), General Health (OR 3.5), Mental Health (OR 2.8), Self Esteem (OR 1.8), Parent Impact—Emotional (OR 1.7) and Parent Impact—Time (OR 1.9). Obese girls were at greater risk of poor health on only two scales: General Health (OR 2.1) and Self Esteem (OR 1.8). Forty-two percent of parents with obese children and 81% with overweight children did not report concern about their childs weight. Parents were more likely to report concern if the child was obese (OR 21.3), overweight (OR 3.5) or underweight (OR 5.4) than normal weight (P<0.05). Concern was not related to child gender, parental BMI or parental education after controlling for child BMI. Perceived health and well-being of overweight/obese children varied little by weight category of the reporting parent (overweight vs non-overweight).Conclusions: Parents were more likely to report poorer health and well-being for overweight and obese children (particularly obese boys). Parental concern about their childs weight was strongly associated with their childs actual BMI. Despite this, most parents of overweight and obese children did not report poor health or well-being, and a high proportion did not report concern. This has implications for the early identification of such children and the success of prevention and intervention efforts.

Television, computer use and body mass index in Australian primary school children

Objective:  To investigate relationships between childrens body mass index (BMI) and parent reports of childrens television and video game/computer habits, controlling for other potential risk factors for paediatric obesity.

Outcome data from the LEAP (Live, Eat and Play) trial: a randomized controlled trial of a primary care intervention for childhood overweight/mild obesity

Objectives:To reduce gain in body mass index (BMI) in overweight/mildly obese children in the primary care setting.Design:Randomized controlled trial (RCT) nested within a baseline cross-sectional BMI survey.Setting:Twenty nine general practices, Melbourne, Australia.Participants:(1) BMI survey: 2112 children visiting their general practitioner (GP) April–December 2002; (2) RCT: individually randomized overweight/mildly obese (BMI z-score <3.0) children aged 5 years 0 months–9 years 11 months (82 intervention, 81 control).Intervention:Four standard GP consultations over 12 weeks, targeting change in nutrition, physical activity and sedentary behaviour, supported by purpose-designed family materials.Main outcome measures:Primary: BMI at 9 and 15 months post-randomization. Secondary: Parent-reported child nutrition, physical activity and health status; child-reported health status, body satisfaction and appearance/self-worth.Results:Attrition was 10%. The adjusted mean difference (intervention–control) in BMI was −0.2 kg/m2 (95% CI: −0.6 to 0.1; P=0.25) at 9 months and −0.0 kg/m2 (95% CI: −0.5 to 0.5; P=1.00) at 15 months. There was a relative improvement in nutrition scores in the intervention arm at both 9 and 15 months. There was weak evidence of an increase in daily physical activity in the intervention arm. Health status and body image were similar in the trial arms.Conclusions:This intervention did not result in a sustained BMI reduction, despite the improvement in parent-reported nutrition. Brief individualized solution-focused approaches may not be an effective approach to childhood overweight. Alternatively, this intervention may not have been intensive enough or the GP training may have been insufficient; however, increasing either would have significant cost and resource implications at a population level.

Predicting Language Outcomes at 4 Years of Age: Findings From Early Language in Victoria Study

OBJECTIVE: To quantify the contributions of child, family, and environmental predictors to language ability at 4 years. METHODS: A longitudinal study was performed with a sample of 1910 infants recruited at 8 months in Melbourne, Australia. Predictors were child gender, prematurity, birth weight and order, multiple birth, socioeconomic status, maternal mental health, vocabulary, education, and age at childs birth, non–English-speaking background, and family history of speech/language difficulties. Outcomes were Clinical Evaluation of Language Fundamentals-Preschool, language scores, low language status (scores >1.25 SDs below the mean), and specific language impairment (SLI) (scores >1.25 SDs below the mean for children with normal nonverbal performance). RESULTS: A total of 1596 children provided outcome data. Twelve baseline predictors explained 18.9% and 20.9% of the variation in receptive and expressive scores, respectively, increasing to 23.6% and 30.4% with the addition of late talking status at age 2. A total of 20.6% of children (324 of 1573 children) met the criteria for low language status and 17.2% (251 of 1462 children) for SLI. Family history of speech/language problems and low maternal education levels and socioeconomic status predicted adverse language outcomes. The combined predictors discriminated only moderately between children with and without low language levels or SLIs (area under the curve: 0.72–0.76); this improved with the addition of late talking status (area under the curve: 0.78–0.84). CONCLUSIONS: Measures of social disadvantage helped explain more variation in outcomes at 4 years than at 2 years, but ability to predict low language status and SLI status remained limited.