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Biomedical subjects

J K Peat

Publications and source records attributed to J K Peat.

At least 19 recordsLinked to original sources
PubMed2003

Gastroschisis: determinants of neonatal outcome.

This retrospective study elicits information regarding the dependence of neonatal outcome in gastroschisis upon: (1) the mode of delivery, (2) place of birth, (3) time for birth to surgery, (4) method of closure, (5) time from operation to commencement of first enteral feeds. The neonatal intensive care database from five major tertiary centres was used to identify 181 neonates with gastroschisis from 1990 to 2000. There were 8 deaths. There were no significant differences in outcome for infants delivered vaginally (102) versus Caesarean section (79), those born near the tertiary centre (133) as compared to infants born away (48), ones operated within 7 hours (125) compared with those operated after 7 hours (56), with delayed closure (30) versus primary closure (151). Neonates fed within 10 days of operation (85) had significantly lower incidence of sepsis, duration of TPN and hospital stay when compared to those fed after 10 days (96). Early commencement of feeds decreases the incidence of sepsis, duration of total parenteral nutrition (TPN) and hospital stay. Place of delivery, mode of delivery, time to surgery and type of closure do not influence neonatal outcome.

Delivery, Obstetric↗
PubMed2003

Use of a paper disposable cup as a spacer is effective for the first-aid management of asthma.

OBJECTIVE: There are many settings in which a spacer device is not available for the administration of bronchodilator. Therefore, we tested whether a paper disposable cup is as effective as a commercially produced spacer to administer bronchodilator. METHODOLOGY: Randomised controlled trial. 50 subjects aged 16-50 years who had wheeze and a greater than 10% decrease in FEV1 after histamine inhalation test (HIT). Subjects were randomised to either the 150 ml paper disposable cup group (CUP) or the commercially produced spacer group (SPACER). Twenty minutes after 400 microg salbutamol was administered FEV1 was measured. The recovery index measured post-bronchodilator FEV1 as a percentage of baseline FEV1. Also, analysis of covariance tested whether recovery of FEV1 was related to the magnitude of the fall following the HIT. RESULTS: There were no statistically significant differences between CUP and SPACER groups in any characteristics. There was no difference for the recovery index (t48=1.14, P=0.26). Regression analyses showed that the relation between the magnitude of the fall in FEV1 during the HIT and the percent recovery was not different between the CUP and SPACER groups (t=-1.2, P<0.23). CONCLUSIONS: A paper disposable cup was effective for the reversal of mild to moderate bronchoconstriction. Therefore, a paper disposable cup can be used for the first-aid management of asthma when there is concern about cross-infection and a commercially produced spacer is not available.

Adolescent↗
PubMed2002

Family and parenting interventions for conduct disorder and delinquency: a meta-analysis of randomised controlled trials.

AIMS: To determine whether family and parenting interventions benefit children and adolescents with conduct disorder and delinquency. METHODS: Meta-analysis of eight randomised controlled trials involving 749 children and adolescents (aged 10-17 years) with conduct disorder and/or delinquency. Criminality, academic performance, future employment, problem behaviour, family functioning, parental mental health, and peer relations were evaluated. RESULTS: Family and parenting interventions significantly reduced the time spent by juvenile delinquents in institutions (weighted mean difference 51.34 days). There was also a significant reduction in the risk of a juvenile delinquent being rearrested (relative risk 0.66) and in their rate of subsequent arrests at 1-3 years (standardised mean difference -0.56). CONCLUSIONS: The evidence suggests that family and parenting interventions for juvenile delinquents and their families have beneficial effects on reducing time spent in institutions and their criminal activity. In addition to the obvious benefit to the participant and their family, this may result in a cost saving for society.

Adolescent↗
PubMed2002

Risk factors for onset and remission of atopy, wheeze, and airway hyperresponsiveness.

BACKGROUND: Although many children with asthma may have a remission as they grow and other children who did not have asthma may develop asthma in adult life, knowledge about the factors that influence the onset and prognosis of asthma during adolescence and young adulthood is very limited. METHODS: A cohort of 8-10 year old children (n=718) living in Belmont, New South Wales, Australia were surveyed six times at 2 yearly intervals from 1982 to 1992, and then again 5 years later in 1997. From this cohort, 498 subjects had between three and seven assessments and were included in the analysis. Atopy, airway hyperresponsiveness (AHR), and wheeze in the last 12 months were measured at each survey. Late onset, remission, and persistence were defined based on characteristics at the initial survey and the changes in characteristics at the follow up surveys. RESULTS: The proportion of subjects with late onset atopy (13.7%) and wheeze (12.4%) was greater than the proportion with remission of atopy (3.2%) and wheeze (5.6%). Having atopy at age 8-12 years (OR 2.8, 95% CI 1.5 to 5.1) and having a parental history of asthma (OR 2.0, 95% CI 1.02 to 4.13) were significant risk factors for the onset of wheeze. Having AHR at age 8-12 years was a significant risk factor for the persistence of wheeze (OR 4.3, 95% CI 1.3 to 15.0). Female sex (OR 1.9, 95% CI 1.01 to 3.60) was a significant risk factor for late onset AHR whereas male sex (OR 1.9, 95% CI 1.1 to 2.8) was a significant risk factor for late onset atopy. CONCLUSIONS: The onset of AHR is uncommon during adolescence, but the risk of acquiring atopy and recent wheeze for the first time continues during this period. Atopy, particularly present at the age of 8-10 years, predicts the subsequent onset of wheeze.

Age of Onset↗
PubMed2001

Clinical importance of Alternaria exposure in children.

The fungus Alternaria is known to be allergenic and is one of the most common fungi worldwide. We investigated the extent to which exposure to Alternaria increases the severity of asthma. We undertook a prospective cohort study in Australia of 399 school children who had positive skin tests to one or more aeroallergens. Airway responsiveness to histamine, wheeze, and bronchodilator use in 1 mo was measured five times between 1997 and 1999. Airway hyperresponsiveness was defined as PD(20)FEV(1) = 3.9 micromol histamine. Airborne concentrations of Alternaria spores were measured throughout the study, and mean daily concentrations over 1 mo ranged from 2.2 to 307.7 spores/m(3) of ambient air. Using generalized estimating equations, we found that airway responsiveness, wheeze, and bronchodilator use increased significantly in association with increased spore concentrations and that the increase in airway responsiveness was greater in children sensitized to Alternaria than in other children (p = 0.01). The odds ratio for airway hyperresponsiveness in children sensitized to Alternaria was 1.26 (95% CI, 1.14 to 1.39) after an increase in mean exposure of 100 spore/m(3)/d over 1 mo. These results suggest that Alternaria allergens contribute to severe asthma in regions where exposure to the fungus is high.

Allergens↗
PubMed2001

Effect of peer led programme for asthma education in adolescents: cluster randomised controlled trial.

OBJECTIVE: To determine the effect of a peer led programme for asthma education on quality of life and related morbidity in adolescents with asthma. DESIGN: Cluster randomised controlled trial. SETTING: Six high schools in rural Australia. PARTICIPANTS: 272 students with recent wheeze, recruited from a cohort of 1515 students from two school years (mean age 12.5 and 15.5 years); 251 (92.3%) completed the study. INTERVENTION: A structured education programme for peers comprising three steps (the "Triple A Program"). MAIN OUTCOME MEASURES: Quality of life, school absenteeism, asthma attacks, and lung function. RESULTS: When adjusted for year and sex, mean total quality of life scores showed significant improvement in the intervention than control group. Clinically important improvement in quality of life (>0.5 units) occurred in 25% of students with asthma in the intervention group compared with 12% in the control group (P=0.01). The number needed to treat was 8 (95% confidence interval 4.5 to 35.7). The effect of the intervention was greatest in students in year 10 and in females. Significant improvements occurred in the activities domain (41% v 28%) and in the emotions domain (39% v 19%) in males in the intervention group. School absenteeism significantly decreased in the intervention group only. Asthma attacks at school increased in the control group only. CONCLUSION: The triple A programme leads to a clinically relevant improvement in quality of life and related morbidity in students with asthma. Wider dissemination of this programme in schools could play an important part in reducing the burden of asthma in adolescents.

Absenteeism↗
PubMed2001

The childhood asthma prevention study (CAPS): design and research protocol of a randomized trial for the primary prevention of asthma.

The Childhood Asthma Prevention Study is a randomized controlled trial to measure whether the incidence of atopy and asthma can be reduced by house dust mite allergen reduction, a diet supplemented with omega-3 fatty acids, or a combination of both interventions. Six hundred and sixteen pregnant women whose unborn children were at high risk of developing asthma because of a family history were randomized prenatally. Study groups are as follows: Group A (placebo diet intervention, no house dust mite reduction), Group B (placebo diet intervention, active house dust mite reduction), Group C (active diet intervention, no house dust mite reduction), and Group D (active diet intervention, active house dust mite reduction). The house dust mite reduction intervention comprises use of physical and chemical methods to reduce allergen contact. The dietary intervention comprises use of a daily oil supplement from 6 months or at onset of bottle-feeding, and use of margarine and cooking oils based on sunflower or canola oils to increase omega-3 dietary intake. Data is collected quarterly until the infant is 1 year old and then half yearly until age 5 years. Questionnaires are used to collect respiratory illness history and information about diet and home environment. Dust is collected from the child's bed and bedroom and playroom floors. Blinded assessments are conducted at 18 months, 3 years, and 5 years. Skin prick tests to common allergens, blood tests, and detailed illness, medication use, and vaccination histories are collected. Primary outcomes will be the development of allergic sensitization and the presence and severity of asthma. This study is designed to measure the effectiveness of allergen reduction and dietary supplementation, both separately and in combination, for the primary prevention of atopy and asthma. The results of this study may have important implications for public health policies to reduce the incidence of childhood asthma. Control Clin Trials 2001;22:333-354

Adult↗
PubMed2001

Predictors of house-dust-mite allergen concentrations in dry regions in Australia.

BACKGROUND: House-dust-mite allergen content differs between houses and is thought to be a function of the housing characteristics and furnishing choices that affect indoor microclimate and mite proliferation. The importance of these features may differ with regional climates. METHODS: Concentrations of mite allergen were analysed as a function of housing features. Information on housing features was collected by questionnaire in 50 houses in two towns in a dry inland region of Australia. Mite allergen (Der p 1) was measured by ELISA in dust samples collected on five occasions over 2 years from beds and floors. RESULTS: Der p 1 was detected in all houses. Many housing features did not influence mite allergen concentrations. However, the presence of evaporative cooling increased mite allergen by 3.34-fold in beds (P=0.007) and 3.94-fold in floors (P=0.003). Mite allergen was threefold higher in mattresses >5 years old, and synthetic and feather duvets tended to have higher and lower levels of mite allergen, respectively. CONCLUSIONS: In houses in dry, inland regions of Australia, evaporative cooling and older mattresses are associated with higher concentrations of mite allergen. Alternative forms of air conditioning to evaporative cooling may be useful for control of mite allergen in dry regions.

Allergens↗
PubMed2001

Abdominal fat and birth size in healthy prepubertal children.

BACKGROUND: Studies examining the foetal origins hypothesis suggest that small birth size may be a marker of foetal adaptations that programme future propensity to adult disease. We explore the hypothesis that birth size may relate to fat distribution in childhood and that fat distribution may be a link between birth size and adult disease. OBJECTIVE: To investigate the relationship between birth size and abdominal fat, blood pressure, lipids, insulin and insulin:glucose ratio in prepubertal children. DESIGN: Cross-sectional study, based on a birth cohort of consecutive full-term births. SUBJECTS: Two hundred and fifty-five (137 females) healthy, 7- and 8-y-old children. MEASUREMENTS: Body composition and abdominal fat was measured by dual energy X-ray absorptiometry. Lipid, glucose and insulin profiles were measured after an overnight fast and an automated BP monitor was used for blood pressure measurements. RESULTS: There was a negative association between abdominal fat and birth weight s.d. score across a range of normal birth weights (beta=-0.18; 95% CI=-0.31 to -0.04, P=0.009) and a positive association with weight s.d. score at 7/8 y (beta=0.35; 95% CI=0.24 to 0.46, P<0.001). Children who were born with the lowest weight s.d. score and had the greatest weight s.d. score at 7/8 y had significantly more (P<0.001) abdominal fat, as a percentage of total fat (6.53+/-1.3%) than those who had the highest birth weight s.d. score and the lowest weight s.d. score at 7/8 y (4.14+/-0.5%). Similar results were seen if head circumference, but not ponderal index, was used as an indicator of birth size. Increased abdominal fat was associated with higher total cholesterol:HDL cholesterol, higher triglyceride concentration and increased diastolic blood pressure. CONCLUSIONS: Birth weight independently predicted abdominal fat. Children with the highest amount of abdominal fat were those who tended to be born lighter and gained weight centiles. Increased abdominal fat was associated with precursor risk factors for ischaemic heart disease.

Abdomen↗
PubMed2001

Having lived on a farm and protection against allergic diseases in Australia.

BACKGROUND: Farmers' children in northern Europe have a lower prevalence of atopy, hay fever and asthma than other children. Farms in Australia differ in scale and operation from those in Europe and the prevalence of allergic diseases in children is higher. OBJECTIVE: To investigate whether having lived on a farm as a child in Australia is associated with a lower risk of allergic diseases. METHODS: Cross-sectional study of children (n = 1500) aged 7-12 years from two rural towns: Wagga Wagga in a mixed farming region, and Moree in a crop farming region. Parents answered a questionnaire and children had a skin prick test for atopy. RESULTS: Twenty percent of children had lived on a farm for at least 1 year. The effect of having lived on a farm differed between the towns (P < 0.001). It was associated with a lower risk of atopy in Wagga (adjusted odds ratio (aOR) 0.47, 95% confidence interval (CI) 0.32-0.72) but not in Moree (aOR 0.97, 95% CI 0.62-1.53). Children from Wagga were more likely to have lived on a livestock farm than children from Moree (26.1% vs. 9.1%, 95% CI for the difference 8.9-25.4). CONCLUSION: Having lived on a farm in Australia can confer protection against atopy in children. Further studies are needed to identify possible protective mechanisms associated with farm animals or to establish whether the protective effect is explained by other related exposures.

Asthma↗
PubMed2001

Impact and aetiology of respiratory infections, asthma and airway disease in Australian Aborigines.

In this review, we describe the burden of respiratory illness in Australian indigenous communities and examine evidence of aetiology. We have reviewed the results from studies of respiratory infections and asthma-like symptoms conducted in remote and non-remote indigenous communities and contrasted them with data from comparable studies in non-indigenous communities. Although bias cannot be controlled and generalizability is an issue, the data are the only information available and, as such, provide a basis for a hypothesis generating approach to better health care. The evidence suggests that many indigenous people, especially those who live in non-remote regions, have asthma-like symptoms that are largely of an infectious rather than an allergic origin. Moreover, indigenous communities continue to be exposed to low immunisation rates, to have low rates of breastfeeding and to have high rates of cigarette smoking, all of which have the potential to increase the prevalence of respiratory illnesses. It is important to identify the most effective treatments and preventive strategies for respiratory symptoms that are prevalent in indigenous children. Respiratory symptoms that are largely of a bacterial-infectious origin may not benefit from commonly prescribed asthma therapies and, without appropriate treatment, may lead to ongoing health problems.

Adolescent↗
PubMed2001

Parental smoking and respiratory tract infections in children.

The adverse health consequences of exposing children to tobacco smoke have been well documented. Re-calculation of the data available from cohort and cross-sectional studies worldwide shows that between 500-2500 excess hospitalisations and between 1000 to 5000 excess diagnoses per 100 000 young children as result from respiratory infections can be directly attributed to parental smoking. Results of published meta-analyses support these figures, which are probably under-estimated because of the effects of non-differential misclassification bias. These excess infections are a source of preventable morbidity and have a high cost to the community. They also have important long-term consequences because children who have respiratory infections in early life are at an increased risk of developing asthma in later childhood. More effective strategies that prevent smoking in young people before they become parents have the potential to lead to reductions in these high rates of unnecessary morbidity in the next generation of children.

Child, Preschool↗
PubMed2001

Continued increase in the prevalence of asthma and atopy.

AIMS: To describe the change in the prevalence of wheeze, diagnosed asthma, and atopy in Wagga Wagga, NSW, Australia, between 1992 and 1997, and to compare this to the increase in prevalence reported between 1982 and 1992. METHODS: A cross sectional study of the prevalence of respiratory symptoms and atopy in schoolchildren aged 8-11 years (n = 1016, response rate 71%) in 1997 compared with studies of similar design in 1992 (response rate 83%, n = 850) and 1982 (response rate 88%, n = 769). Main outcome measures were respiratory symptoms measured by parent completed questionnaire and atopy measured by skin prick tests. RESULTS: Between 1992 and 1997, the prevalence of wheeze increased by 5.1% (95% CI 1.2 to 9.0), asthma diagnosis by 8.1% (95% CI 3.8 to 12.4), and atopy by 6.7% (95% CI 2.2 to 11.2). Similar increases in prevalence had been found between 1982 and 1992. CONCLUSIONS: The prevalence of wheeze, asthma diagnosis, and atopy in Wagga Wagga has continued to increase.

Asthma↗
PubMed2001

Obesity is a risk for asthma and wheeze but not airway hyperresponsiveness.

BACKGROUND: A study was undertaken to assess whether the recent increases in prevalence of both asthma and obesity are linked and to determine if obesity is a risk factor for diagnosed asthma, symptoms, use of asthma medication, or airway hyperresponsiveness. METHODS: Data from 1971 white adults aged 17-73 years from three large epidemiological studies performed in NSW were pooled. Doctor diagnosis of asthma ever, history of wheeze, and medication use in the previous 12 months were obtained by questionnaire. Body mass index (BMI) in kg/m(2) was used as a measure of obesity. Airway hyperresponsiveness (AHR) was defined as dose of <3.9 micromol histamine required to provoke a fall in forced expiratory volume in one second (FEV(1)) of 20% or more (PD(20)FEV(1)). Adjusted odds ratios (OR) were obtained by logistic regression. RESULTS: After adjusting for atopy, age, sex, smoking history, and family history, severe obesity was a significant risk factor for recent asthma (OR 2. 04, p=0.048), wheeze in the previous 12 months (OR 2.6, p=0.001), and medication use in the previous 12 months (OR 2.83, p=0.005), but not for AHR (OR 0.87, p=0.78). FEV(1) and forced vital capacity (FVC) were significantly reduced in the group with severe obesity, but FEV(1)/FVC ratio, peak expiratory flow (PEF), and mid forced expiratory flow (FEF(25-75)) were not different from the group with normal BMI. The underweight group (BMI <18.5 kg/m(2)) had increased symptoms of shortness of breath, increased airway responsiveness, and reduced FEV(1), FVC, PEF, and FEF(25-75) with similar use of asthma medication as subjects in the normal weight range. CONCLUSIONS: Although subjects with severe obesity reported more wheeze and shortness of breath which may suggest a diagnosis of asthma, their levels of atopy, airway hyperresponsiveness, and airway obstruction did not support the suggestion of a higher prevalence of asthma in this group. The underweight group appears to have more significant respiratory problems with a higher prevalence of symptoms, reduced lung function, and increased airway responsiveness without an increase in medication usage. This group needs further investigation.

Adolescent↗
PubMed2001

Continuing the debate about measuring asthma in population studies.

The reasons for measuring atopy and airway hyperresponsiveness (AHR) and the methods of validating measurements of asthma in population studies continue to be debated. The debate has centred around standards against which to validate asthma measurements but the absence of a "gold standard" makes the criterion validation of measurements difficult. Questionnaires will always be useful but cannot be validated against a doctor diagnosis because of self-selection and recall biases. In practice, measurements should be selected on the merits of what they measure rather than being regarded as validated or non-validated alternatives. The measurement of AHR is invaluable because it is reliable, not influenced by variations in symptom perception or diagnostic trends, and is closely related to the underlying mechanisms of asthma. The value of AHR lies in its high specificity (rate of true negatives) and low sensitivity (rate of false positives) against asthma symptoms which gives additional information about symptomatic subjects. Atopy is also a useful test and, in quantifying its association with asthma, we should not place any currency on ecological evidence. Atopy is a strong risk factor for asthma in the presence of regionally specific allergens and ecological analyses that ignore these effects are diversionary rather than productive. For preventing asthma, we need to identify the group at greatest risk of developing it, measure the risk factors with precision, and develop interventions that are effective in changing environmental exposures and homogeneous outcomes. This is the only approach that has the potential to lead to significant public health benefits.

Asthma↗
PubMed2001

Asthma in preschool children: prevalence and risk factors.

BACKGROUND: The prevalence of asthma in children has increased in many countries over recent years. To plan effective interventions to reverse this trend we need a better understanding of the risk factors for asthma in early life. This study was undertaken to measure the prevalence of, and risk factors for, asthma in preschool children. METHODS: Parents of children aged 3-5 years living in two cities (Lismore, n=383; Wagga Wagga, n=591) in New South Wales, Australia were surveyed by questionnaire to ascertain the presence of asthma and various proposed risk factors for asthma in their children. Recent asthma was defined as ever having been diagnosed with asthma and having cough or wheeze in the last 12 months and having used an asthma medication in the last 12 months. Atopy was measured by skin prick tests to six common allergens. RESULTS: The prevalence of recent asthma was 22% in Lismore and 18% in Wagga Wagga. Factors which increased the risk of recent asthma were: atopy (odds ratio (OR) 2.35, 95% CI 1.49 to 3.72), having a parent with a history of asthma (OR 2.05, 95% CI 1.34 to 3.16), having had a serious respiratory infection in the first 2 years of life (OR 1.93, 95% CI 1.25 to 2.99), and a high dietary intake of polyunsaturated fats (OR 2.03, 95% CI 1.15 to 3.60). Breast feeding (OR 0.41, 95% CI 0.22 to 0.74) and having three or more older siblings (OR 0.16, 95% CI 0.04 to 0.71) decreased the risk of recent asthma. CONCLUSIONS: Of the factors tested, those that have the greatest potential to be modified to reduce the risk of asthma are breast feeding and consumption of polyunsaturated fats.

Asthma↗
PubMed2001

Problems and possibilities in understanding the natural history of asthma.

In early life, asthma symptoms can occur intermittently or may not be severe enough to limit normal activities, which makes it difficult for the clinician to make reliable predictions and administer therapy with some precision. In the case of pediatric asthma, the identification of children who will experience the development of a clinically important illness that will impair their quality of life can be a complex process. The usual methods for describing this information include the prognostic statistics of sensitivity, specificity, likelihood ratio, and positive predictive value. The sensitivity, specificity, and likelihood ratio of various early markers of asthma have been calculated from several cohort studies. (J Allergy Clin Immunol 2000;106:S144-52.)

Asthma↗