Lactose malabsorption (LM) in children was diagnosed by an elevated breath hydrogen (BH) level following a 10g lactose load. A portable gas chromatograph and a semiconductor detector, designed and constructed for use in the Pacific Islands is described. Following verification on known malabsorber and. normal subjects, the technique was used to determine the prevalence of LM in Europeans at Auckland and Rarotonga, and in Samoans at two locations in Auckland and two locations in Western Samoa. The prevalence of LM in Europeans was significantly (p<0.01) higher at Rarotonga than at Auckland. For Samoans, the prevalence of LM was significantly (p<0.01) higher in Western Samoa than at Auckland. The prevalence of LM was very highly significantly (p<0.001) related to race. Each child tested for LM filled in a questionaire to determine attitude, consumption of and perceived intolerance to milk, milk biscuits and ice cream. Lactose malabsorption was significantly (p<0.05) correlated to milk consumption and to attitude to dairy products, but not to sex, age, and perceived intolerance. The consumption of dairy products was very highly significantly (p<0.0001) correlated to attitude, and highly significantly (p<0.001) correlated to location and perceived intolerance. There was no significant correlation between consumption and race, sex or age. Perceived intolerance to individual dairy products was significantly correlated to attitude to milk (p<0.0001), milk biscuits (p<0.02) and ice cream (p<0.001). Perceived intolerance was not related to age, sex, race, location or the actual symptoms following the consumption of 10g lactose. The unexpected finding of increased LM in the Pacific Islands, was investigated further by studying the LM status of the Medical Team during a visit to western Samoa, and by performing a microbiological survey of water quality. It was found that half of the Medical Team 3/6, became malabsorbers during the week spent in Western Samoa. On returning to New Zealand it was shown that lactase levels took 3 months to normalise. The water supply in Western Samoa was shown to contain very high levels of coliform bacteria. The currently held hypothesis that genetic factors are solely involved in the onset of LM, was not supported. The evidence from the survey supported environmental factors are also involved in adult onset LM. The hypothesis suggesting that dietary lactose was a requirement for retaining elevated lactase levels, was tested using Galactosemic and Phenyl Ketonuria patients. None of the patients had developed LM although they had been on a low lactose diet for years, hence the theory was not supported. The BH method proved highly successful in diagnosing LM with many of the children actually enjoying it.

In newborn infants, birth asphyxia represents the predominant cause of brain injury. These infants will later exhibit neurodevelopmental disabilities or a more major cerebral palsy. Prevention of adverse outcomes requires an understanding of the way in which these deficits develop. Endogenous protective mechanisms arising from the insult have opened new insights in neuroprotective strategies. Neurotrophic factors such as IGF-1 and its N-terminal tripeptide GPE have been shown to confer some neuroprotection after HI injury in the adult rodent. In the P21 rat brain after moderate HI injury, exogenous intracerebral and intraperitoneal injections of GPE (30μg and 300μg respectively) were neuroprotective in the hippocampus and lateral cortex possibly through binding to glia as detected by autoradiography of 3H-GPE. In the preterm infant the mechanisms of white matter injury remain to be clearly elucidated. To mimic the pattern of diffuse cerebral injury of the very preterm infant, a transient moderate focal HI injury has been applied on the immature P3 rat. This new model showed a significant reduction in the lateral cortical volume with reduction and alteration of the myelination pattern in the cortical white matter (WM) at P21. These cortical alterations result from neuro-axonal damage 24h after the insult as shown with Fluoro-Jade B staining and β-APP accumulation. In addition activated astrocytes from 24h after HI up to P21 were present. This model should enable us to elucidate some of the pathogenic mechanisms involved in diffuse WM injury. Brain damage in the developing brain has two components: 1) the pattern and mechanisms of injury are correlated with the stage of development at the time of injury; 2) it will influence subsequent brain development.

Ovine placental lactogen (oPL) is secreted by the placenta into both the fetal and maternal compartments. Its biological function(s) during pregnancy and the mechanisms involved are still unclear. A purification procedure was developed for oPL from sheep placental cotyledons of late gestation. Four procedures were attempted to obtain homogeneous oPL. Recoveries of oPL and total protein were measured throughout the several procedures using a specific oPL RIA and the Bradford protein estimation respectively. The third and fourth procedures resulted in homogeneous oPL and a partial amino acid sequence was obtained from the fourth procedure. In the successful procedures, the placental tissue was extracted with 0.1 M ammonium bicarbonate pH 8.5. A pH precipitation of the soluble fraction was performed, followed by 60% saturation with ammonium sulphate. Further separation steps involved chromatogaphic procedures. Carboxymethylcellulose (CM32) cation exchange was performed batchwise at pH 5.6. Subsequently chromatofocusing was performed to elute proteins in order of their isoelectric points. This was carried out using a pH gadient of 0.9 to 6.0. The final chromatographic step was reverse-phase high performance liquid chromatography (RP-HPLC) using a C4 column. To obtain homogeneous oPL in the third procedure, the partially purified oPL was subjected to SDS polyacrylamide gel electrophoresis and the separated proteins were transferred to nitrocellulose membrane. The homogeneous oPL was eluted from the membrane, however, sequencing was unsuccessful. It was assumed that the N terminal of oPL was blocked. Homogeneous oPL was obtained in the fourth procedure by electrophoretic elution from the Hunkapiller gel system performed at 4°C. The oPL was digested with trypsin, the fragments were separated by RP-HPLC chromatography and two peptides were sequenced. Peptide 1: F D E Q Y G Q G I Peptide 2: Y I N C H T Several strategies were attempted to provide more homogeneous oPL to enable more sequencing. The partially purified oPL fractions from each of these attempts were pooled and electrophoresed on an SDS polyacrylamide gel. The section of acrylamide containing the oPL band was homogenised and a trypsin digest was performed. The digested oPL was separated from the gel pieces, filtered through a Sep-Pak filter and the fragments were separated by RP-HPLC. The yield of oPL was low, but sufficient homogeneous oPL was obtained to provide a partial amino acid sequence from tryptic peptides. A further two peptides provided sequences. Peptide 3: (L) A G E M V N R F D E Q Y G Q G I Peptide 4: (L) Q P G K C Q I P L Q S L F Collaborators from Genentech Inc (San Francisco USA) used partially purified oPL produced from the present study and also obtained homogeneous oPL (Colosi et al., 1989). Complementary DNA clones of oPL were isolated and expressed in mammalian cells by recombinant DNA techniques (Colosi et al., 1989). These clones were sequenced, demonstrating that the full sequence of oPL consists of 198 amino acids preceded by a 38 amino acid sequence signal. Recombinant oPL was generated by Colosi et al. (1989) which provided sufficient material to perform physiological studies in vivo. The somatogenic effects of recombinant oPL were investigated in the growth hormone (GH) deficient dwarf rat and compared to identical doses of recombinant bovine GH (bGH) in 3 independent studies. Both oPL and bGH treatments resulted in an increase (p<0.05) in body weight gain compared to that in saline treated controls, with oPL treatment being more potent than bGH (p<0.05). In promoting linear growth, oPL was more potent (p<0.05) than bGH in some instances. Nitrogen content of dry carcass matter was increased with oPL treatment compared to saline (p<0.05), with a nonsignificant increase in bGH treated animals. Carcass fat was similarly reduced by both oPL and bGH treatment (p<0.05) compared to saline. Serum insulin-like growth factor I (IGF-I) concentrations were increased significantly (p<0.05) by both oPL and bGH treatments, with a significantly greater effect of oPL suggested in one study. No increase in hepatic IGF-I mRNA was evident with either treatment, suggesting that the increase in serum IGF-I is due to posttranscriptional mechanisms. The expression of IGF binding protein 3 (IGFBP-3) hepatic mRNA was increased (p<0.05) with bGH treatment compared to that after saline treatment, but was unaffected by opL treatment, indicating regulation by GH at the transcriptional level. The binding of [125I]bGH to hepatic membrane preparations demonstrated no difference in specific binding compared to that in saline controls. However, [125I]oPL specific binding was greater in oPL treated animals (p<0.05). Animals treated with bGH had reduced (p<0.05) hepatic GH receptor mRNA compared to saline controls, but oPL treatment had no effect. Thus, oPL is a potent anabolic and lipolytic agent in the dwarf rat, exerting greater somatogenic effects on some parameters than bGH. The studies in this thesis have described biochemical and biological characterisitics of oPL. The amino acid sequence of oPL is more closely related to prolactin (PRL) than to GH (Colosi et al., 1989). However, oPL has potent somatogenic activities in the GH deficient dwarf rat. Our data suggest differences in receptor binding and effects on GH receptor and IGFBP-3 expression with these two treatments, raising the possibility of actions through different pathways or differential effects at the GH receptor level. These results do not fully resolve whether GH and PRL exert all effects through a single receptor or whether there is a separate PL receptor.

The introduction to this thesis is a literature review. Kramer, in a study commissioned by WHO, reviewed the literature prior to 1985 on low birthweight. This is extended, mainly in respect to infants who are small for gestational age with emphasis on important findings in relation to birthweight since that time. Work in New Zealand on birthweight is also summarised. The literature is also reviewed in respect to the mechanisms in the pathway between the placenta and the fetus, and in respect to recent work suggesting a link between birthweight and disease in adult life. This thesis examines factors that influence birthweight and placental weight. Birthweight for gestational age percentile curves for the New Zealand population were firstly defined. small for gestational age (SGA) infants could then be categorised. The thesis considers two sources of data, the first a cross-sectional sample of the New Zealand population from 1987 to 1990 (the control subjects of the New Zealand cot Death study, a national case-control study on sudden infant death syndrome), and the second a hospital population in Auckland (National Womens Hospital (l992)). These two datasets are investigated to determine factors that influence birthweight in a univariate situation and then in the multivariate situation. Independent variables are considered using a priori categorisations and where appropriate Quantile-Quantile (Q-Q) derived categorisations determined by producing plots of the quantiles of cases versus controls. A number of variables under the headings of socio-demographic, lifestyle, genetic, obstetric and nutrition are examined and found to be associated with the outcomes of interest at the univariate level. After controlling in multivariate analyses a number of variables are found to be no longer significant, however some show strong relationships. The variable relating to smoking in both datasets shows the greatest detrimental effect on the outcomes considered in respect to birthweight. This confirms that in New Zealand, as in other places in the world, smoking has significant consequences on birthweight. The data is also investigated for the timing of insult to the fetus from smoking, and is found to be most important during pregnancy. comparison of the results comparing those obtained using a binary outcome for SGA, and those obtained using birthweight continuously, show relatively consistent results. The odds ratios and the decreases in birthweight obtained from both datasets show a relatively linear relationship between the two. An examination into whether a distinct group of individuals exists in respect to having large placentae for birthweight, indentified an artefact in the dataset relating to recording of placental weight for twins. After removal of twins from the dataset, examination of factors that influence placental weight showed that the factors that influence placental weight are not the same as those that influence birthweight. In particular smoking is found not to influence placental weight, and haemoglobin, which has no influence on birthweight, is found to be inversely associated with placental weight. other factors such as parity are found to influence placental weight in the same proportion in which birthweight is affected. In conclusion this thesis shows that factors investigated in New Zealand are consistent with findings in the international literature in relation to birthweight. The results on factors that influence placental weight add to the international literature on a topic on which little work has been carried out. The results of this thesis point to areas where future research needs to be carried out, in particular in relation to maternal nutrition during pregnancy and maternal energy expenditure during pregnancy. There is also a need for further research into the relationships of factors on placental weight and the ratio of birthweight to placental weight, and how these relationships affect health outcomes in childhood and adult life.

Over the past decade, a number of epidemiological studies have provided significant evidence that certain major adult noncommunicable diseases, such as hypertension, ischaemic heart disease and non-insulin dependent diabetes mellitus, may be associated with impaired fetal growth. This phenomenon has been termed "programming" which is essentially the term used for persisting changes in structure and function caused by undernutrition or other adverse influences acting during critical periods of early development. Programming has been used as the mechanistic basis to explain the long term sequelae of intrauterine growth retardation (IUGR). The mechanisms underlying the epidemiological observations remain to be elucidated and developed. While it is well established that severe maternal undernutrition during pregnancy leads to IUGR, there has been relatively little well defined animal studies of the somatotrophic axis and postnatal development of growth retarded offspring. The major objectives of this thesis were to establish a model in the rat of IUGR by nutritional restriction of the dam throughout gestation and to examine the effects of fetal growth retardation on endocrine, molecular and growth parameters during postnatal development. In addition, the development of an animal model for IUGR enabled well defined studies testing distinct hypotheses suggested by the epidemiological observations of professor David Barker and colleagues. Timed matings were performed in Wistar rats and dams were randomly assigned to one of two dietary treatment groups. A control group was fed ad libitum throughout pregnancy and a restricted group was fed 30% of ad libitum intake. Restricted fed dams were observed to lose a significant amount of body weight throughout gestation, due to undernutrition, but caught up to the ad libitum group during the lactating period. Maternal undernutrition significantly reduced fetal and placental weights without altering litter size. Postnatally, body weights of offspring from undernourished dams continued to be reduced until at least 18 weeks of age, although they were observed to be growing at the same rate as ad libitum offspring by 2 weeks of age. A cohort of animals from undernourished dams were maintained to measure blood pressure by tail cuff plethysmography. Offspring from undernourished dams were found to have significantly elevated systolic blood pressures from 18 weeks of age. This observation provides direct experimental support for the hypothesis, derived from human epidemiological studies, that the origin of adult hypertension may originate during fetal life as a result of exposure to a sub-optimal intrauterine environment. Parallel reductions in plasma IGF-I and hepatic IGF-I mRNA concentrations before 15 days of age were also observed in growth retarded offspring. Hepatic IGF-I transcription start sites within exon 1 and exon 2 were coordinately reduced with IUGR up to 15 days of age without changes in GHR and GHBP mRNA abundance. The lack of catch-up growth observed in the IUGR offspring despite normalization of their plasma IGF-I and IGF-I mRNA levels from 15 days of age may be due to a state of partial resistance to GH. This observation lead to a series of treatment studies in which neonatal and juvenile offspring from ad libitum and undernourished dams were treated with growth factors to investigate somatic growth responses as a measure for hormone sensitivity. In both treatment studies, ad libitum offspring from both age groups and juvenile IUGR offspring responded to GH treatment However, neonatal IUGR offspring did not exhibit any response to GH treatment.. Analysis of IGF-I gene expression in neonatal offspring showed that GH treatment elevated IGF-I Eb mRNA in ad libitum but not IUGR offspring. These results suggest a possible mechanism for transient GH resistance in that a post-receptor defect in GH action may contribute to the development of temporary postnatal GH resistance as a consequence of IUGR and fetal programming of IGF-I gene expression. In summary, the development of a model of IUGR in the rat using maternal undernutrition throughout gestation has enabled detailed investigation of nutritional regulation of the somatotrophic axis during fetal development and postnatal sequelae. The studies in this thesis have shown that the somatotrophic axis is markedly altered postnatally by nutritional restriction of the dam throughout gestation, leading to prolonged postnatal growth retardation and elevated blood pressure The mechanisms which lead to the induction of such fetal programming and whether these changes may contribute to the development of subsequent adult-onset disease remain to be addressed in future studies.

The developmental origins of health and disease hypothesis suggests that exposure to adverse prenatal environmental influences can determine an individual’s susceptibility to obesity in adult life. However, the specific causal mechanisms which underlie this hypothesis have yet to be identified. Focusing on the potential mechanistic role of the leptin endocrine axis, the main objective of this thesis was to investigate the long term effects of prenatal undernutrition and different levels of postnatal nutrition on leptin sensitivity and the development of diet-induced obesity (DIO) in the Wistar rat. A well established animal model of maternal undernutrition during pregnancy was used to induce prenatal undernutrition in experimental offspring. To investigate the interaction between prenatal nutrition and postnatal diet, and its effects on obesity development, female offspring were placed on three different diets: standard chow, a high fat diet or a calorie restricted diet. The effects of prenatal undernutrition and postnatal diet on leptin sensitivity were investigated, in adult offspring, by measuring the response to 14 days of peripheral leptin treatment. Changes in gene expression in the liver, retroperitoneal adipose tissue and soleus muscle were then characterised by custom microarray and quantitative real-time RT-PCR (QPCR) analysis. Adult female offspring exposed to prenatal undernutrition (UN offspring) were found to exhibit leptin resistance in adulthood, independent of postnatal DIO. This result demonstrates for the first time that exposure to prenatal undernutrition has a long term effect on adult leptin sensitivity. In UN offspring fed on a high-fat diet, leptin resistance significantly accelerated the development of DIO while in contrast, offspring maintained on calorie restriction remained lean. These findings suggest that prenatal nutrition can shape future susceptibility to DIO by altering postnatal leptin sensitivity. An analysis of gene expression suggests that prenatal undernutrition causes the development of peripheral tissue-specific leptin resistance, and may also further enhance an offspring’s susceptibility to DIO by altering the regulation of peripheral tissue lipogenesis, mitochondrial function, glucocorticoid metabolism and insulin sensitivity. In conclusion, these studies identify peripheral leptin resistance as a key mechanism that can influence postnatal susceptibility to DIO in female offspring exposed to prenatal undernutrition. Furthermore, the identification of specific changes in peripheral gene expression highlights four additional metabolic mechanisms which may also facilitate the development of DIO in leptin resistant UN offspring.

No description available.

Whole document restricted until August 2010, see Access Instructions file below for details of how to access the print copy. / Abstract Background Asthma is a common problem in New Zealand, and is associated with significant morbidity and costs to children, their families, and wider society. Previously published New Zealand literature suggested that Māori and Pacific children were less likely than NZ European children to receive asthma medications and elements of asthma education, had poorer knowledge of asthma, and experienced greater morbidity and hospitalisations. However, none of the previous literature had been specifically designed to assess the nature of asthma care in the community, or to specifically answer whether there were ethnic disparities in care. A systematic review of studies published in the international literature that compared asthma management among different ethnic groups drawn from community-based samples was undertaken. The results of this review suggested that minority ethnic group children were less likely to receive elements of asthma medication use, asthma education and self-management (action) plans. Objectives The primary objectives of the study were to: • describe the use of medications, medication delivery systems, asthma education, and self-management plans in primary care for Māori, Pacific, and Other ethnic group children • ascertain whether there were any ethnic disparities in the use of medications, medication delivery systems, asthma education, and self-management plans in primary care after controlling for differences in socio-economic position and other potential confounders. Secondary objectives were to: • describe the asthma-related utilisation of GP, after hours medical care, emergency departments, and hospital admissions among Māori, Pacific, and Other ethnic group children with asthma • ascertain whether differences in medication use, the provision of asthma education, and the provision of self-management plans explained ethnic differences in health service utilisation. Methods A cross-sectional survey was conducted in Auckland, New Zealand. The caregivers of 647 children who were aged 2–14 years, had a diagnosis of asthma or experienced ‘wheeze or whistling in the chest’, and had experienced symptoms in the previous 12 months were identified using random residential address start points and door knocking. Ethnically stratified sampling ratios were used to ensure that approximately equal numbers of children of Māori, Pacific and Other ethnicity were enrolled into the study. A face-to-face interview was conducted with the caregivers of these children. Data was collected about: socio-demographic factors; asthma morbidity; asthma medications and delivery devices; exposure to, and experiences of, asthma education and asthma action plans; and asthma-related health services utilisation. Results In this study, the caregivers of 647 eligible children were invited to participate and 583 completed the interview, giving an overall completion rate of 90.1%. There were no ethnic differences in completion rates. The overall use of inhaled corticosteroid medications had increased since previous New Zealand research was published. Multivariable modelling that adjusted for potential confounders did not identify ethnic differences in the use of inhaled corticosteroids or oral steroids. Some findings about medication delivery mechanisms indicated that care was not consistent with guidelines. About 15% of participants reported they had not received asthma education from a primary care health professional. After adjusting for potential confounders there were no ethnic differences in the likelihood of having received asthma education from a health professional. Among those participants who had received education from a primary care health professional, significantly fewer Māori and Pacific caregivers reported receiving education about asthma triggers, pathophysiology and action plans. Lower proportions of Pacific (77.7%; 95% confidence interval (95%CI) 70.3, 85.1) and Māori (79.8%; 95% CI 73.6, 85.9) caregivers were given information about asthma triggers compared to Other caregivers (89.2%; 95% CI 84.9, 93.6; p=0.01). Fewer Māori (63.6%; 95% CI 55.7, 71.4) and Pacific (68.1%; 95% CI 60.1, 76.1) caregivers reported receiving information about pathophysiology (Other 75.9%; 95% CI 69.5, 82.3; p=0.05). Information about asthma action plans had been given to 22.7% (95% CI 15.5, 29.9) of Pacific and 32.9% (95% CI 25.3, 40.6) of Māori compared to Other participants (36.5%; 95% CI 28.6, 44.3; p=0.04). In addition, fewer Māori (64.2%; 95% CI 56.1, 72.3) and Pacific (68.5%; 95% CI 60.1, 77.0) reported that the information they received was clear and easy to understand (Other 77.9%; 95% CI 71.8, 84.1; p=0.03). About half of those who had received education from a health professional reported receiving further education and, after adjustment for potential confounders, Pacific caregivers were less likely to have been given further education (odds ratio 0.57; 95% confidence interval 0.33, 0.96). A minority of participants (35.3%) had heard about action plans and, after adjustment for potential confounders, Pacific caregivers were less likely to have heard about these plans (odds ratio 0.54; 95% confidence interval 0.33, 0.96). About 10% of the sample was considered to have a current action plan. The mean number of visits to a GP for acute and routine asthma care (excluding after-hours doctors and medical services) in the previous twelve months were significantly higher for Pacific (3.89; CI 3.28, 4.60) and Māori (3.56; CI 3.03, 4.16) children than Other ethnic group children (2.47; CI 2.11, 2.85; p<0.0001). Multivariable modelling of health service utilization outcomes (‘number of GP visits for acute and routine asthma care in the previous twelve months’, ‘high use of hospital emergency departments’, and ‘hospital admissions’) showed that adjustment for potential confounding and asthma management variables reduced, but did not fully explain, ethnic differences in these outcomes. Māori children experienced 22% more GP visits and Pacific children 28% more visits than Other children (p=0.05). Other variables that were significantly associated with a higher number of GP visits were: regular source of care they always used (regression coefficient (RC) 0.24; p<0.01); lower household income (RC 0.31; p=0.004) and having a current action plan (RC 0.38; p=0.006). Increasing age (RC -0.04; p=0.003), a lay source of asthma education (RC -0.41; p=0.001), and higher scores on asthma management scenario (RC -0.03; p=0.05) were all associated with a lower number of GP visits. Pacific (odds ratio (OR) 6.93; 95% CI 2.40, 19.98) and Māori (OR 2.60; 95% CI 0.87, 8.32) children were more likely to have used an emergency department for asthma care in the previous twelve months (p=0.0007). Other variables that had a significant effect on the use of EDs in the multivariable model were: not speaking English in the home (OR 3.72; 95% CI 1.52, 9.09; p=0.004), male sex (OR 2.43; 95% CI 1.15, 5.15; p=0.02), and having a current action plan (OR 7.85; 95% CI 3.49, 17.66; p<0.0001). Increasing age was associated with a reduced likelihood of using EDs (OR 0.90; 95% CI 0.81, 1.00; p=0.05). Hospitalisations were more likely in the Pacific (OR 8.94; 95% CI 2.25, 35.62) and Māori (OR 5.40; 95% CI 1.28, 23.06) ethnic groups (p=0.007). Four other variables had a significant effect on hospital admissions in the multivariable model. Participants who had a low income (OR 3.70; 95% CI 1.49, 9.18; p=0.005), and those who had a current action plan (OR 8.39; 95% CI 3.85, 18.30; p<0.0001) were more likely to have been admitted to hospital in the previous 12 months. Increasing age (OR 0.88; 95% CI 0.80, 0.98; p=0.02) and parental history of asthma (OR 0.39; 95% CI 0.18, 0.85; p=0.02) were associated with reduced likelihood of admission. Conclusions The study is a robust example of cross-sectional design and has high internal validity. The study population is representative of the population of children with asthma in the community. The three ethnic groups are also considered to be representative of those ethnic groups in the community. The study, therefore, has good representativeness and the findings of the study can be generalised to the wider population of children with asthma in the Auckland region. The results suggested that some aspects of pharmacological management were more consistent with guideline recommendations than in the past. However, given the higher burden of disease experienced by Māori and Pacific children, the lack of observed ethnic differences in the use of preventative medications may reflect under treatment relative to need. There are important ethnic differences in the provision of asthma education and action plans. Future approaches to improving care should focus on interventions to assist health professionals to implement guideline recommendations and to monitor ethnic disparities in their practice. Asthma education that is comprehensive, structured and delivered in ways that are effective for the people concerned is needed.

Background Asthma is a common problem in New Zealand, and is associated with significant morbidity and costs to children, their families, and wider society. Previously published New Zealand literature suggested that M��ori and Pacific children were less likely than NZ European children to receive asthma medications and elements of asthma education, had poorer knowledge of asthma, and experienced greater morbidity and hospitalisations. However, none of the previous literature had been specifically designed to assess the nature of asthma care in the community, or to specifically answer whether there were ethnic disparities in care. A systematic review of studies published in the international literature that compared asthma management among different ethnic groups drawn from community-based samples was undertaken. The results of this review suggested that minority ethnic group children were less likely to receive elements of asthma medication use, asthma education and self-management (action) plans. Objectives The primary objectives of the study were to: ��� describe the use of medications, medication delivery systems, asthma education, and self-management plans in primary care for M��ori, Pacific, and Other ethnic group children ��� ascertain whether there were any ethnic disparities in the use of medications, medication delivery systems, asthma education, and self-management plans in primary care after controlling for differences in socio-economic position and other potential confounders. Secondary objectives were to: ��� describe the asthma-related utilisation of GP, after hours medical care, emergency departments, and hospital admissions among M��ori, Pacific, and Other ethnic group children with asthma ��� ascertain whether differences in medication use, the provision of asthma education, and the provision of self-management plans explained ethnic differences in health service utilisation. Methods A cross-sectional survey was conducted in Auckland, New Zealand. The caregivers of 647 children who were aged 2���14 years, had a diagnosis of asthma or experienced ���wheeze or whistling in the chest���, and had experienced symptoms in the previous 12 months were identified using random residential address start points and door knocking. Ethnically stratified sampling ratios were used to ensure that approximately equal numbers of children of M��ori, Pacific and Other ethnicity were enrolled into the study. A face-to-face interview was conducted with the caregivers of these children. Data was collected about: socio-demographic factors; asthma morbidity; asthma medications and delivery devices; exposure to, and experiences of, asthma education and asthma action plans; and asthma-related health services utilisation. Results In this study, the caregivers of 647 eligible children were invited to participate and 583 completed the interview, giving an overall completion rate of 90.1%. There were no ethnic differences in completion rates. The overall use of inhaled corticosteroid medications had increased since previous New Zealand research was published. Multivariable modelling that adjusted for potential confounders did not identify ethnic differences in the use of inhaled corticosteroids or oral steroids. Some findings about medication delivery mechanisms indicated that care was not consistent with guidelines. About 15% of participants reported they had not received asthma education from a primary care health professional. After adjusting for potential confounders there were no ethnic differences in the likelihood of having received asthma education from a health professional. Among those participants who had received education from a primary care health professional, significantly fewer M��ori and Pacific caregivers reported receiving education about asthma triggers, pathophysiology and action plans. Lower proportions of Pacific (77.7%; 95% confidence interval (95%CI) 70.3, 85.1) and M��ori (79.8%; 95% CI 73.6, 85.9) caregivers were given information about asthma triggers compared to Other caregivers (89.2%; 95% CI 84.9, 93.6; p=0.01). Fewer M��ori (63.6%; 95% CI 55.7, 71.4) and Pacific (68.1%; 95% CI 60.1, 76.1) caregivers reported receiving information about pathophysiology (Other 75.9%; 95% CI 69.5, 82.3; p=0.05). Information about asthma action plans had been given to 22.7% (95% CI 15.5, 29.9) of Pacific and 32.9% (95% CI 25.3, 40.6) of M��ori compared to Other participants (36.5%; 95% CI 28.6, 44.3; p=0.04). In addition, fewer M��ori (64.2%; 95% CI 56.1, 72.3) and Pacific (68.5%; 95% CI 60.1, 77.0) reported that the information they received was clear and easy to understand (Other 77.9%; 95% CI 71.8, 84.1; p=0.03). About half of those who had received education from a health professional reported receiving further education and, after adjustment for potential confounders, Pacific caregivers were less likely to have been given further education (odds ratio 0.57; 95% confidence interval 0.33, 0.96). A minority of participants (35.3%) had heard about action plans and, after adjustment for potential confounders, Pacific caregivers were less likely to have heard about these plans (odds ratio 0.54; 95% confidence interval 0.33, 0.96). About 10% of the sample was considered to have a current action plan. The mean number of visits to a GP for acute and routine asthma care (excluding after-hours doctors and medical services) in the previous twelve months were significantly higher for Pacific (3.89; CI 3.28, 4.60) and M��ori (3.56; CI 3.03, 4.16) children than Other ethnic group children (2.47; CI 2.11, 2.85; p<0.0001). Multivariable modelling of health service utilization outcomes (���number of GP visits for acute and routine asthma care in the previous twelve months���, ���high use of hospital emergency departments���, and ���hospital admissions���) showed that adjustment for potential confounding and asthma management variables reduced, but did not fully explain, ethnic differences in these outcomes. M��ori children experienced 22% more GP visits and Pacific children 28% more visits than Other children (p=0.05). Other variables that were significantly associated with a higher number of GP visits were: regular source of care they always used (regression coefficient (RC) 0.24; p<0.01); lower household income (RC 0.31; p=0.004) and having a current action plan (RC 0.38; p=0.006). Increasing age (RC -0.04; p=0.003), a lay source of asthma education (RC -0.41; p=0.001), and higher scores on asthma management scenario (RC -0.03; p=0.05) were all associated with a lower number of GP visits. Pacific (odds ratio (OR) 6.93; 95% CI 2.40, 19.98) and M��ori (OR 2.60; 95% CI 0.87, 8.32) children were more likely to have used an emergency department for asthma care in the previous twelve months (p=0.0007). Other variables that had a significant effect on the use of EDs in the multivariable model were: not speaking English in the home (OR 3.72; 95% CI 1.52, 9.09; p=0.004), male sex (OR 2.43; 95% CI 1.15, 5.15; p=0.02), and having a current action plan (OR 7.85; 95% CI 3.49, 17.66; p<0.0001). Increasing age was associated with a reduced likelihood of using EDs (OR 0.90; 95% CI 0.81, 1.00; p=0.05). Hospitalisations were more likely in the Pacific (OR 8.94; 95% CI 2.25, 35.62) and M��ori (OR 5.40; 95% CI 1.28, 23.06) ethnic groups (p=0.007). Four other variables had a significant effect on hospital admissions in the multivariable model. Participants who had a low income (OR 3.70; 95% CI 1.49, 9.18; p=0.005), and those who had a current action plan (OR 8.39; 95% CI 3.85, 18.30; p<0.0001) were more likely to have been admitted to hospital in the previous 12 months. Increasing age (OR 0.88; 95% CI 0.80, 0.98; p=0.02) and parental history of asthma (OR 0.39; 95% CI 0.18, 0.85; p=0.02) were associated with reduced likelihood of admission. Conclusions The study is a robust example of cross-sectional design and has high internal validity. The study population is representative of the population of children with asthma in the community. The three ethnic groups are also considered to be representative of those ethnic groups in the community. The study, therefore, has good representativeness and the findings of the study can be generalised to the wider population of children with asthma in the Auckland region. The results suggested that some aspects of pharmacological management were more consistent with guideline recommendations than in the past. However, given the higher burden of disease experienced by M��ori and Pacific children, the lack of observed ethnic differences in the use of preventative medications may reflect under treatment relative to need. There are important ethnic differences in the provision of asthma education and action plans. Future approaches to improving care should focus on interventions to assist health professionals to implement guideline recommendations and to monitor ethnic disparities in their practice. Asthma education that is comprehensive, structured and delivered in ways that are effective for the people concerned is needed.

Whole document restricted until August 2010, see Access Instructions file below for details of how to access the print copy. / Abstract Background Asthma is a common problem in New Zealand, and is associated with significant morbidity and costs to children, their families, and wider society. Previously published New Zealand literature suggested that Māori and Pacific children were less likely than NZ European children to receive asthma medications and elements of asthma education, had poorer knowledge of asthma, and experienced greater morbidity and hospitalisations. However, none of the previous literature had been specifically designed to assess the nature of asthma care in the community, or to specifically answer whether there were ethnic disparities in care. A systematic review of studies published in the international literature that compared asthma management among different ethnic groups drawn from community-based samples was undertaken. The results of this review suggested that minority ethnic group children were less likely to receive elements of asthma medication use, asthma education and self-management (action) plans. Objectives The primary objectives of the study were to: • describe the use of medications, medication delivery systems, asthma education, and self-management plans in primary care for Māori, Pacific, and Other ethnic group children • ascertain whether there were any ethnic disparities in the use of medications, medication delivery systems, asthma education, and self-management plans in primary care after controlling for differences in socio-economic position and other potential confounders. Secondary objectives were to: • describe the asthma-related utilisation of GP, after hours medical care, emergency departments, and hospital admissions among Māori, Pacific, and Other ethnic group children with asthma • ascertain whether differences in medication use, the provision of asthma education, and the provision of self-management plans explained ethnic differences in health service utilisation. Methods A cross-sectional survey was conducted in Auckland, New Zealand. The caregivers of 647 children who were aged 2–14 years, had a diagnosis of asthma or experienced ‘wheeze or whistling in the chest’, and had experienced symptoms in the previous 12 months were identified using random residential address start points and door knocking. Ethnically stratified sampling ratios were used to ensure that approximately equal numbers of children of Māori, Pacific and Other ethnicity were enrolled into the study. A face-to-face interview was conducted with the caregivers of these children. Data was collected about: socio-demographic factors; asthma morbidity; asthma medications and delivery devices; exposure to, and experiences of, asthma education and asthma action plans; and asthma-related health services utilisation. Results In this study, the caregivers of 647 eligible children were invited to participate and 583 completed the interview, giving an overall completion rate of 90.1%. There were no ethnic differences in completion rates. The overall use of inhaled corticosteroid medications had increased since previous New Zealand research was published. Multivariable modelling that adjusted for potential confounders did not identify ethnic differences in the use of inhaled corticosteroids or oral steroids. Some findings about medication delivery mechanisms indicated that care was not consistent with guidelines. About 15% of participants reported they had not received asthma education from a primary care health professional. After adjusting for potential confounders there were no ethnic differences in the likelihood of having received asthma education from a health professional. Among those participants who had received education from a primary care health professional, significantly fewer Māori and Pacific caregivers reported receiving education about asthma triggers, pathophysiology and action plans. Lower proportions of Pacific (77.7%; 95% confidence interval (95%CI) 70.3, 85.1) and Māori (79.8%; 95% CI 73.6, 85.9) caregivers were given information about asthma triggers compared to Other caregivers (89.2%; 95% CI 84.9, 93.6; p=0.01). Fewer Māori (63.6%; 95% CI 55.7, 71.4) and Pacific (68.1%; 95% CI 60.1, 76.1) caregivers reported receiving information about pathophysiology (Other 75.9%; 95% CI 69.5, 82.3; p=0.05). Information about asthma action plans had been given to 22.7% (95% CI 15.5, 29.9) of Pacific and 32.9% (95% CI 25.3, 40.6) of Māori compared to Other participants (36.5%; 95% CI 28.6, 44.3; p=0.04). In addition, fewer Māori (64.2%; 95% CI 56.1, 72.3) and Pacific (68.5%; 95% CI 60.1, 77.0) reported that the information they received was clear and easy to understand (Other 77.9%; 95% CI 71.8, 84.1; p=0.03). About half of those who had received education from a health professional reported receiving further education and, after adjustment for potential confounders, Pacific caregivers were less likely to have been given further education (odds ratio 0.57; 95% confidence interval 0.33, 0.96). A minority of participants (35.3%) had heard about action plans and, after adjustment for potential confounders, Pacific caregivers were less likely to have heard about these plans (odds ratio 0.54; 95% confidence interval 0.33, 0.96). About 10% of the sample was considered to have a current action plan. The mean number of visits to a GP for acute and routine asthma care (excluding after-hours doctors and medical services) in the previous twelve months were significantly higher for Pacific (3.89; CI 3.28, 4.60) and Māori (3.56; CI 3.03, 4.16) children than Other ethnic group children (2.47; CI 2.11, 2.85; p<0.0001). Multivariable modelling of health service utilization outcomes (‘number of GP visits for acute and routine asthma care in the previous twelve months’, ‘high use of hospital emergency departments’, and ‘hospital admissions’) showed that adjustment for potential confounding and asthma management variables reduced, but did not fully explain, ethnic differences in these outcomes. Māori children experienced 22% more GP visits and Pacific children 28% more visits than Other children (p=0.05). Other variables that were significantly associated with a higher number of GP visits were: regular source of care they always used (regression coefficient (RC) 0.24; p<0.01); lower household income (RC 0.31; p=0.004) and having a current action plan (RC 0.38; p=0.006). Increasing age (RC -0.04; p=0.003), a lay source of asthma education (RC -0.41; p=0.001), and higher scores on asthma management scenario (RC -0.03; p=0.05) were all associated with a lower number of GP visits. Pacific (odds ratio (OR) 6.93; 95% CI 2.40, 19.98) and Māori (OR 2.60; 95% CI 0.87, 8.32) children were more likely to have used an emergency department for asthma care in the previous twelve months (p=0.0007). Other variables that had a significant effect on the use of EDs in the multivariable model were: not speaking English in the home (OR 3.72; 95% CI 1.52, 9.09; p=0.004), male sex (OR 2.43; 95% CI 1.15, 5.15; p=0.02), and having a current action plan (OR 7.85; 95% CI 3.49, 17.66; p<0.0001). Increasing age was associated with a reduced likelihood of using EDs (OR 0.90; 95% CI 0.81, 1.00; p=0.05). Hospitalisations were more likely in the Pacific (OR 8.94; 95% CI 2.25, 35.62) and Māori (OR 5.40; 95% CI 1.28, 23.06) ethnic groups (p=0.007). Four other variables had a significant effect on hospital admissions in the multivariable model. Participants who had a low income (OR 3.70; 95% CI 1.49, 9.18; p=0.005), and those who had a current action plan (OR 8.39; 95% CI 3.85, 18.30; p<0.0001) were more likely to have been admitted to hospital in the previous 12 months. Increasing age (OR 0.88; 95% CI 0.80, 0.98; p=0.02) and parental history of asthma (OR 0.39; 95% CI 0.18, 0.85; p=0.02) were associated with reduced likelihood of admission. Conclusions The study is a robust example of cross-sectional design and has high internal validity. The study population is representative of the population of children with asthma in the community. The three ethnic groups are also considered to be representative of those ethnic groups in the community. The study, therefore, has good representativeness and the findings of the study can be generalised to the wider population of children with asthma in the Auckland region. The results suggested that some aspects of pharmacological management were more consistent with guideline recommendations than in the past. However, given the higher burden of disease experienced by Māori and Pacific children, the lack of observed ethnic differences in the use of preventative medications may reflect under treatment relative to need. There are important ethnic differences in the provision of asthma education and action plans. Future approaches to improving care should focus on interventions to assist health professionals to implement guideline recommendations and to monitor ethnic disparities in their practice. Asthma education that is comprehensive, structured and delivered in ways that are effective for the people concerned is needed.