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Background: The Global Asthma Network (GAN), by using the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, has updated trends in prevalence of symptoms of childhood allergic diseases, including non‐infective rhinitis and conjunctivitis ('rhinoconjunctivitis'), which is reported here. Methods: Prevalence and severity of rhinoconjunctivitis were assessed by questionnaire among schoolchildren in GAN Phase I and ISAAC Phase I and III surveys 15–23 years apart. Absolute rates of change in prevalence were estimated for each centre and modelled by multi‐level linear regression to compare trends by age group, time period and per capita national income. Results: Twenty‐seven GAN centres in 14 countries surveyed 74,361 13‐ to 14‐year‐olds ('adolescents') and 45,434 6‐ to 7‐year‐olds ('children'), with average response proportions of 90% and 79%, respectively. Many centres showed highly significant (p <.001) changes in prevalence of rhinoconjunctivitis in the past year ('current rhinoconjunctivitis') compared with ISAAC. The direction and magnitude of centre‐level trends varied significantly (p <.001) both within and between countries. Overall, current rhinoconjunctivitis prevalence decreased slightly from ISAAC Phase III to GAN: −1.32% per 10 years, 95% CI [−2.93%, +0.30%] among adolescents; and −0.44% [−1.29%, +0.42%] among children. Together, these differed significantly (p <.001) from the upward trend within ISAAC. Among adolescents, centre‐level trends in current rhinoconjunctivitis were highly correlated with those for eczema symptoms (rho = 0.72, p <.0001) but not with centre‐level trends in asthma symptoms (rho = 0.15, p =.48). Among children, these correlations were positive but not significant. Conclusion: Symptoms of non‐infective rhinoconjunctivitis among schoolchildren may no longer be on the increase globally, although trends vary substantially within and between countries. [ABSTRACT FROM AUTHOR]

Aim: To examine the relationship between reported vigorous physical activity (VPA) and body mass index (BMI) in children (6-7 years) and adolescents (13-14 years).Methods: In the International Study of Asthma and Allergies in Childhood Phase Three, 75 895 children's parents and 199 502 adolescents answered questions relating to VPA, height and weight. The association between VPA and BMI was analysed using general linear models, adjusting for country gross national index.Results: Compared to children who undertook no VPA, those in the infrequent group (once or twice per week) and those in the frequent group (three or more times per week) had mean (95% CI) BMI values 0.07 kg/m2 (0.03-0.11) and 0.09 kg/m2 (0.03-0.15) greater, respectively (p = 0.001). Compared to adolescents reporting no VPA, those in the infrequent group had a BMI 0.19 kg/m2 (0.15-0.23) greater while those in the frequent group had a BMI 0.01 kg/m2 (-0.03-0.05) greater (p < 0.0001).Conclusion: Reported VPA is not associated with lower BMI among children and adolescents. Investigation of VPA and BMI may be best undertaken in conjunction with other variables in the energy expenditure equation. A focus on VPA alone may be an inefficient way to manage BMI. [ABSTRACT FROM AUTHOR]

OBJECTIVES: This study tested the hypothesis that immunization is related to the prevalence of atopic disease in childhood. METHODS: We used data from the International Study of Asthma and Allergies in Childhood to perform an ecologic analysis of national and local immunization rates for tuberculosis, diphtheria and tetanus toxoids and pertussis (DTP), and measles and prevalence of atopic disease symptoms (asthma, allergic rhinoconjunctivitis, and atopic eczema). RESULTS: In 13- to 14-year-old children, there were significant negative associations with local birth-year immunization rates for DTP and measles but none with rates for tuberculosis. No associations were found in 6- to 7-year-old children. No associations with national immunization rates were found. CONCLUSIONS: International variations in childhood atopic diseases are unlikely to be explained by variations in immunization. [ABSTRACT FROM AUTHOR]

Background: To examine whether responses to questions about the lifetime prevalence and 12-month period prevalence of symptoms of asthma and allergies are affected by the season in which the questions are asked.Methods: The international Study of Asthma and Allergies in Childhood (ISAAC) Phase One was undertaken in six New Zealand centres; in three centres the effect of season was studied. Over three school terms at least 3000 children were studied in each of two age groups per centre (6-7 years; 13-14 years), one-third in each term respectively. The ISAAC standardized written questionnaires were used to identify asthma, rhinitis and eczema symptoms. The written questionnaire in the younger age group was completed by the parent/guardian. The older age group self-completed the written questionnaire and also a video questionnaire about asthma symptoms.Results: The total number of respondents was 21,437, approximately half in each age group. The season of responding had no effect on the level of response to eczema questions. For the written asthma questionnaire no season-of-response effect was present for 6-7 year olds; for 13-14 year olds there was a trend to a higher rate of positive responses by those responding in winter, but in only one question did this reach statistical significance. With the video questionnaire there was a similar trend for a higher rate of positive responses when questions were asked in winter, but this did not reach statistical significance. For rhinitis symptoms there was a statistically significant season-of-response effect in both age groups with two questions; the fewest positive responses by the winter responders.Conclusions: There was no significant effect of season-of-response to questions on eczema symptoms, and most questions on asthma symptoms. There was a season-of-response effect on responses to questions on rhinitis symptoms suggesting a recall bias relating to recency of symptoms. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phases I and III of the International Study of Asthma and Allergies in Childhood (ISAAC) documented increased asthma symptoms among Nigerian 13-14-year old adolescents. We investigated the trend further using the Global Asthma Network (GAN) surveillance. METHODS: Using ISAAC methodology, GAN Phase I data on symptoms and risk factors for asthma and asthma management were obtained from February to July 2018. RESULTS: There were 2,897 adolescents from 23 secondary schools. For current wheeze, there was an absolute prevalence fall per decade of -1.4 with -1 standard error (SE) in 16 years from 2002 (ISAAC Phase III) to 2018 (GAN Phase I). This pattern was evident for prevalence of reported asthma ever, severe asthma symptoms and night cough with ≥1 SE. During the 23-year interval between ISAAC Phase I and GAN Phase I, there was a fall (≥1 SE) in the absolute prevalence of reported asthma ever, severe asthma symptoms and night cough, except for severe asthma symptoms (-0.2 SE). Respectively 36% and 43% of symptomatic adolescents purchased and used salbutamol and prednisolone. CONCLUSION: The prevalence and severity of asthma symptoms remain high among adolescents in Ibadan. This could be mitigated by improved access to affordable and effective asthma treatments.

Background: Asthma is one of the most common non-communicable diseases globally. This study aimed to assess asthma medicine use, management plan availability, and disease control in childhood, adolescence, and adulthood across different country settings., Methods: We used data from the Global Asthma Network Phase I cross-sectional epidemiological study (2015-20). A validated, written questionnaire was distributed via schools to three age groups (children, 6-7 years; adolescents, 13-14 years; and adults, ≥19 years). Eligible adults were the parents or guardians of children and adolescents included in the surveys. In individuals with asthma diagnosed by a doctor, we collated responses on past-year asthma medicines use (type of inhaled or oral medicine, and frequency of use). Questions on asthma symptoms and health visits were used to define past-year symptom severity and extent of asthma control. Income categories for countries based on gross national income per capita followed the 2020 World Bank classification. Proportions (and 95% CI clustered by centre) were used to describe results. Generalised structural equation multilevel models were used to assess factors associated with receiving medicines and having poorly controlled asthma in each age group., Findings: Overall, 453 473 individuals from 63 centres in 25 countries were included, comprising 101 777 children (6445 [6·3%] with asthma diagnosed by a doctor), 157 784 adolescents (12 532 [7·9%]), and 193 912 adults (6677 [3·4%]). Use of asthma medicines varied by symptom severity and country income category. The most used medicines in the previous year were inhaled short-acting β2 agonists (SABA; range across age groups, 29·3-85·3% participants) and inhaled corticosteroids (12·6-51·9%). The proportion of individuals with severe asthma symptoms not taking inhaled corticosteroids (inhaled corticosteroids alone or with long-acting β2 agonists) was high in all age groups (934 [44·8%] of 2085 children, 2011 [60·1%] of 3345 adolescents, and 1142 [55·5%] of 2058 adults), and was significantly higher in middle-to-low-income countries. Oral SABA and theophylline were used across age groups and country income categories, contrary to current guidelines. Asthma management plans were used by 4049 (62·8%) children, 6694 (53·4%) adolescents, and 3168 (47·4%) adults; and 2840 (44·1%) children, 6942 (55·4%) adolescents, and 4081 (61·1%) adults had well controlled asthma. Independently of country income and asthma severity, having an asthma management plan was significantly associated with the use of any type of inhaled medicine (adjusted odds ratio [OR] 2·75 [95% CI 2·40-3·15] for children; 2·45 [2·25-2·67] for adolescents; and 2·75 [2·38-3·16] for adults) or any type of oral medicine (1·86 [1·63-2·12] for children; 1·53 [1·40-1·68] for adolescents; and 1·78 [1·55-2·04] for adults). Poor asthma control was associated with low country income (lower-middle-income and low-income countries vs high-income countries, adjusted OR 2·33 [95% CI 1·32-4·14] for children; 3·46 [1·83-6·54] for adolescents; and 4·86 [2·55-9·26] for adults)., Interpretation: Asthma management and control is frequently inadequate, particularly in low-resource settings. Strategies should be implemented to improve adherence to asthma treatment guidelines worldwide, with emphasis on access to affordable and quality-assured essential asthma medicines especially in low-income and middle-income countries., Funding: International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca, UK National Institute for Health Research, UK Medical Research Council, European Research Council, the Spanish Instituto de Salud Carlos III., Translation: For the Spanish translation of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests KM reports receiving advisory board fees from AstraZeneca, outside the submitted work. GBM reports grants and non-financial support from AstraZeneca and grants from GlaxoSmithKline Australia and Novartis Australia, outside the submitted work. RM reports receiving consulting fees from AstraZeneca and Merck Sharpe & Dohme (Organon) and honoraria for educational events organised by AstraZeneca. All other authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Aims: Asthma, hay fever and eczema are three common chronic conditions. There have been no recent multi-country data on the burden of these three conditions in adults; the aims of this study are to fill this evidence gap., Methods: The Global Asthma Network Phase I is a multi-country cross-sectional population-based study using the same core methodology as the International Study of Asthma and Allergies in Childhood Phase III. It provides data on the burden of asthma, hay fever and eczema in children and adolescents, and, for the first time, in their parents/guardians., Results: Data were available from 193 912 adults (104 061 female; mean±sd age 38±7.5 years) in 43 centres in 17 countries. The overall prevalence (range) of symptoms was 6.6% (0.9-32.7%) for current wheeze, 4.4% (0.9-29.0%) for asthma ever, 14.4% (2.8-45.7%) for hay fever ever and 9.9% (1.6-29.5%) for eczema ever. Centre prevalence varied considerably both between countries and within countries. There was a moderate correlation between hay fever ever and asthma ever, and between eczema ever and hay fever ever at the centre level. There were moderate to strong correlations between indicators of the burden of disease reported in adults and the two younger age groups., Conclusion: We found evidence for a substantial burden of asthma, hay fever ever and eczema ever in the countries examined, highlighting the major public health importance of these diseases. Prevention strategies and equitable access to effective and affordable treatments for these three conditions would help mitigate the avoidable morbidity they cause., Competing Interests: Conflict of interest: The authors declare that they have no conflict of interest., (Copyright ©The authors 2022.)

Aims: There have been no worldwide standardised surveys of prevalence and severity of asthma, rhinoconjunctivitis and eczema in school children for 15 years. The present study aims to provide this information., Methods: Following the exact International Study of Asthma and Allergies in Childhood (ISAAC) methodology (cross-sectional questionnaire-based survey), Global Asthma Network (GAN) Phase I was carried out between 2015 and 2020 in many centres worldwide., Results: The study included 157 784 adolescents (13-14 years of age) in 63 centres in 25 countries and 101 777 children (6-7 years of age) in 44 centres in 16 countries. The current prevalence of symptoms, respectively, was 11.0% and 9.1% for asthma, 13.3% and 7.7% for rhinoconjunctivitis and 6.4% and 5.9% for eczema. The prevalence of asthma ever was 10.5% and 7.6%, hay fever ever was 15.2% and 11.1% and eczema ever was 10.6% and 13.4%, respectively. Centres in low or lower middle gross national income countries (LICs or LMICs) had significantly lower prevalence of the three disease symptoms and diagnoses (except for hay fever). In children, the prevalence of asthma and rhinoconjunctivitis symptoms was higher in boys, while the reverse occurred among adolescents. For eczema, while the prevalence among female adolescents was double that of males, there was no sex difference among children. Centre accounted for non-negligible variability in all disease symptoms (10-20%)., Conclusion: The burdens of asthma, rhinoconjunctivitis and eczema vary widely among the limited number of countries studied. Although symptom prevalence is lower in LICs and LMICs, it represents a considerable burden everywhere studied., Competing Interests: Conflict of interest: C.E. Rutter declares UK Medical Research Council funding for a PhD as part of MRCLID DTP with LSHTM and St Georges, grant number MR/N013638/1, in connection with the present manuscript. All other authors declare no competing interests., (Copyright ©The authors 2022.)

Background: Asthma is the most common chronic disease in children globally. The Global Asthma Network (GAN) Phase I study aimed to determine if the worldwide burden of asthma symptoms is changing., Methods: This updated cross-sectional study used the same methods as the International study of Asthma and Allergies in Childhood (ISAAC) Phase III. Asthma symptoms were assessed from centres that completed GAN Phase I and ISAAC Phase I (1993-95), ISAAC Phase III (2001-03), or both. We included individuals from two age groups (children aged 6-7 years and adolescents aged 13-14 years) who self-completed written questionnaires at school. We estimated the 10-year rate of change in prevalence of current wheeze, severe asthma symptoms, ever having asthma, exercise wheeze, and night cough (defined by core questions in the questionnaire) for each centre, and we estimated trends across world regions and income levels using mixed-effects linear regression models with region and country income level as confounders., Findings: Overall, 119 795 participants from 27 centres in 14 countries were included: 74 361 adolescents (response rate 90%) and 45 434 children (response rate 79%). About one in ten individuals of both age groups had wheeze in the preceding year, of whom almost half had severe symptoms. Most centres showed a change in prevalence of 2 SE or more between ISAAC Phase III to GAN Phase I. Over the 27-year period (1993-2020), adolescents showed a significant decrease in percentage point prevalence per decade in severe asthma symptoms (-0·37, 95% CI -0·69 to -0·04) and an increase in ever having asthma (1·25, 0·67 to 1·83) and night cough (4·25, 3·06 to 5·44), which was also found in children (3·21, 1·80 to 4·62). The prevalence of current wheeze decreased in low-income countries (-1·37, -2·47 to -0·27], in children and -1·67, -2·70 to -0·64, in adolescents) and increased in lower-middle-income countries (1·99, 0·33 to 3·66, in children and 1·69, 0·13 to 3·25, in adolescents), but it was stable in upper-middle-income and high-income countries., Interpretation: Trends in prevalence and severity of asthma symptoms over the past three decades varied by age group, country income, region, and centre. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective therapies for asthma., Funding: International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca Educational Grant, National Institute for Health Research, UK Medical Research Council, European Research Council, and Instituto de Salud Carlos III., Competing Interests: Declaration of interests KM reports receiving advisory board fees from AstraZeneca, outside the submitted work. GBM reports grants and non-financial support from AstraZeneca and grants from GlaxoSmithKline Australia and Novartis Australia, outside the submitted work. All other authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

This review of trends in worldwide asthma prevalence starts with defining how asthma prevalence is measured in populations and how it is analysed. Four population studies of asthma across at least two regions are described: European Community Respiratory Health Survey (ECRHS), the International Study of Wheezing in Infants (EISL), the International Study of Asthma and Allergies in Childhood (ISAAC) and the World Health Survey (WHS). Two of these (ISAAC and WHS) covered all the regions of the world; each using its own standardised questionnaire-based methodology with cross-sectional study design, suitable for large populations. EISL (2005 and 2012) and ISAAC (1996-1997 and 2002-2003) have undertaken a second cross-sectional population survey from which trends are available: EISL in three centres in two countries; ISAAC 106 centres in 56 countries (13-14 year olds) and 66 centres in 37 countries (6-7 year olds). Key results from these studies are presented. Unfortunately, there is no new worldwide data outside of EISL since 2003. Global Burden of Disease estimates of asthma prevalence have varied greatly. Recent reliable worldwide data on asthma prevalence and trends is needed; the Global Asthma Network Phase I will provide this in 2021., Competing Interests: Conflict of interest: M.I. Asher has nothing to disclose. Conflict of interest: L. García-Marcos has nothing to disclose. Conflict of interest: N.E. Pearce has nothing to disclose. Conflict of interest: D.P. Strachan has nothing to disclose., (Copyright ©ERS 2020.)

Background-The Global Asthma Network (GAN) Phase I is surveying school pupils in high-income and low- or middle-income countries using the International Study of Asthma and Allergies in Childhood (ISAAC) methodology. Methods-Cross-sectional surveys of participants in two age groups in randomly selected schools within each centre (2015-2020). The compulsory age group is 13-14 years (adolescents), optionally including parents or guardians. Six to seven years (children) and their parents are also optional. Adolescents completed questionnaires at school, and took home adult questionnaires for parent/guardian completion. Children took home questionnaires for parent/guardian completion about the child and also adult questionnaires. Questions related to symptoms and risk factors for asthma and allergy, asthma management, school/work absence and hospitalisation. Results-53 centres in 20 countries completed quality checks by 31 May 2020. These included 21 centres that previously participated in ISAAC. There were 132,748 adolescents (average response rate 88.8%), 91,802 children (average response rate 79.1%), and 177,622 adults, with >97% answering risk factor questions and >98% answering questions on asthma management, school/work absence and hospitalisation. Conclusion-The high response rates achieved in ISAAC have generally been maintained in GAN. GAN Phase I surveys, partially overlapping with ISAAC centres, will allow within-centre analyses of time-trends in prevalence.

Background: Symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema in children cluster at both the individual and population levels., Objectives: To assess individual-level and school-level risk factors for symptoms of rhinoconjunctivitis and compare them to corresponding associations with symptoms of asthma and eczema in Phase Three of the International Study of Asthma and Allergies in Childhood., Methods: We studied 116,863 children aged 6-7 years from 2163 schools in 59 centres and 22 countries and 224,436 adolescents aged 13-14 years from 2037 schools in 97 centres in 41 countries. Multilevel logistic regression models were fitted with random intercepts for school, centre, and country, adjusting for sex and maternal education at the child level. Associations between symptoms and a range of lifestyle and environmental risk factors were assessed for both the child's exposure and mean exposure at the school. Models were fitted for rhinoconjunctivitis, asthma, and eczema singly (unimorbidity) and for combinations of these conditions (multimorbidity)., Results: Generally, associations between symptoms and exposures at the school level were similar in direction and magnitude to those at the child level. Associations with multimorbidity were stronger than for unimorbidity, particularly in individuals with symptoms of all three diseases, but risk factor associations found in conventional single disease analyses persisted among children with only one condition, after excluding multimorbid groups.Comparisons of individuals with only one disease showed that many risk factor associations were consistent across the three conditions. More strongly associated with asthma were low birthweight, cat exposure in infancy, and current maternal smoking. Current paracetamol use was more strongly associated with asthma and rhinoconjunctivitis than eczema. Breastfeeding was more strongly associated with eczema than asthma or rhinoconjunctivitis.The direction and magnitude of most risk factor associations were similar in affluent and non-affluent countries, although notable exceptions include farm animal contact in infancy and larger sibships, which were associated with increased risk of rhinoconjunctivitis in non-affluent countries but reduced risk in affluent countries. In both age groups, current paracetamol use increased risk of each disease to a greater extent in affluent countries than in non-affluent countries. Effects of paracetamol and antibiotics in infancy were more consistent between richer and poorer settings., Conclusions: Most of the environmental and lifestyle correlates of rhinoconjunctivitis, asthma and eczema in childhood display similarity across the three conditions, even in less affluent settings where allergic sensitisation is less likely to explain the concordant epidemiological patterns., Trial Registration: Not applicable., Competing Interests: The authors report no competing interests., (© 2020 The Authors.)

Background: Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC) measured the global prevalence of symptoms of asthma in children. We undertook comprehensive analyses addressing risk factors for asthma symptoms in combination, at both the individual and the school level, to explore the potential role of reverse causation due to selective avoidance or confounding by indication., Objective: To explore the role of reverse causation in risk factors of asthma symptoms., Methods: We compared two sets of multilevel logistic regression analyses, using (a) individual level exposure data and (b) school level average exposure (ie prevalence), in two different age groups. In individual level analyses, reverse causation is a possible concern if individual level exposure statuses were changed as a result of asthma symptoms or diagnosis. School level analyses may suffer from ecologic confounding, but reverse causation is less of a concern because individual changes in exposure status as a result of asthma symptoms would only have a small effect on overall school exposure levels., Results: There were 131 924 children aged 6-7 years (2428 schools, 25 countries) with complete exposure, outcome and confounder data. The strongest associations in individual level analyses (fully adjusted) were for current paracetamol use (odds ratio = 2.06; 95% confidence interval 1.97-2.16), early life antibiotic use (1.65; 1.58-1.73) and open fire cooking (1.44; 1.26-1.65). In school level analyses, these risk factors again showed increased risks. There were 238 586 adolescents aged 13-14 years (2072 schools, 42 countries) with complete exposure, outcome and confounder data. The strongest associations in individual level analyses (fully adjusted) were for current paracetamol use (1.80; 1.75-1.86), cooking on an open fire (1.32; 1.22-1.43) and maternal tobacco use (1.23; 1.18-1.27). In school level analyses, these risk factors again showed increased risks., Conclusions & Clinical Relevance: These analyses strengthen the potentially causal interpretation of previously reported individual level findings, by providing evidence against reverse causation., (© 2018 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.)

To determine incidence and outcome of biliary atresia (BA) between ethnic groups in New Zealand (NZ), a retrospective review was undertaken of children with BA born between 2002 and 2014. Prioritized ethnicity was used to determine ethnicity and was compared to population data. Uni- and multivariate analyses were undertaken to determine demographic and biochemical factors associated with outcome. Overall incidence was 1 in 9181 (Māori 1 in 5285; European 1 in 16,228; P < 0.0001). Overall and transplant-free survival rates at 1, 2, and 5 years were 92%, 86%, 82% and 70%, 49%, 30% respectively with Māori having improved transplant-free survival (P < 0.05) despite European children undergoing Kasai earlier (49 vs 63 days). BA is more common in NZ than Europe and North America, which is attributable to a higher incidence in Māori but overall outcome is poorer. Māori have improved transplant-free survival compared to NZ European children but the reason is unknown.

The Global Asthma Network (GAN), established in 2012, followed the International Study of Asthma and Allergies in Childhood (ISAAC). ISAAC Phase One involved over 700 000 adolescents and children from 156 centres in 56 countries; it found marked worldwide variation in symptom prevalence of asthma, rhinitis and eczema that was not explained by the current understanding of these diseases; ISAAC Phase Three involved over 1 187 496 adolescents and children (237 centres in 98 countries). It found that asthma symptom prevalence was increasing in many locations especially in low- and middle-income countries where severity was also high, and identified several environmental factors that required further investigation.GAN Phase I, described in this article, builds on the ISAAC findings by collecting further information on asthma, rhinitis and eczema prevalence, severity, diagnoses, asthma emergency room visits, hospital admissions, management and use of asthma essential medicines. The subjects will be the same age groups as ISAAC, and their parents. In this first global monitoring of asthma in children and adults since 2003, further evidence will be obtained to understand asthma, management practices and risk factors, leading to further recognition that asthma is an important non-communicable disease and to reduce its global burden., (Copyright ©ERS 2017.)

Research Question: Can the distribution of fast food outlets be obtained and effectively used to identify if there is a relationship between the placement of these and the prevalence and severity of asthma, rhinoconjunctivitis and eczema (ARE) in children and adolescents?, Method: Fast food restaurant location data was obtained for seven countries. Data from the International Study of Asthma and Allergies in Childhood (ISAAC) was used from 53 centres in the same seven countries. Each ISAAC centre provided a detailed map of the study area. The location of restaurants and ISAAC centres were overlaid using the ArcMap software, and the number of restaurants within each ISAAC centre counted. Bivariate regression analysis was used to compare outlet density with ARE prevalence and severity., Results: The results from the analyses showed a positive (non-significant) trend on a regression plot between outlet density and ARE severity. This project has shown that it is practical to systematically obtain and map fast food outlets and compare their distribution worldwide with the prevalence and severity of diseases, in this case ARE. The devised methodology has proven to be an efficient way to obtain restaurant distribution data in a form that is manageable and suitable to compare with area based disease prevalences. This project has shown that a larger scale investigation is both feasible and warranted., (Copyright © 2015 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.)

Background: Global variations in the prevalence of asthma and related diseases have suggested that environmental factors are causative, and that factors associated with urbanisation are of particular interest. A range of definitions for 'urban' and 'rural' have been used in articles on asthma and related diseases, making it difficult to assess their importance as aetiological factors. This study sets out to examine such definitions used in the literature., Methods: Medical and social science databases were searched for articles that made distinctions of 'urban' and/or 'rural' in the context of asthma and related diseases., Results: The search identified 73 articles and categorised four types of definitions. A specific definition of urban or rural was used in 19 (26%) articles. Nine (12%) articles used non-specific and/or administrative definitions. There were 23 (32%) articles that described locations as 'urban' or 'rural' but did not indicate if the description defined 'urban' or 'rural'. Distinctions were made between urban and rural locations without a description or definition in 22 (30%) articles., Conclusions: There is substantial variation in the definitions of 'urban' and 'rural' in articles regarding asthma and related diseases. It would be advantageous to have clearer and more precise definitions of 'urban' and 'rural' which could facilitate aetiological research and also comparisons between locations, especially in international studies., (Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.)

Background: The upper airway humidifies and warms inspired gases before they reach the trachea, a process bypassed by the insertion of a tracheostomy, necessitating humidification of inspired gases. The optimal method of humidification is not known., Methods: We conducted a short-term 20-hour study and a long-term 10-week randomized crossover study comparing a heated humidifier (HH) to a heat and moisture exchanger (HME) in children with established tracheostomies. Subjects were assessed for clinical events, clinical examination findings, airway cytokine levels, and airway secretion viscoelasticity., Results: For the short-term study, 15 children were recruited; for the long-term study, 14 children were recruited. Children using the HH had decreased respiratory examination score (P < .001) but no change in clinical events over the short term. There was a decrease in acute clinical events (P = .008) in the long-term study. No differences were found in airway secretion viscoelasticity results or cytokine levels in either study, but these sample numbers were limited., Conclusions: Over 20 hours use, HH, compared to HME, improved work of breathing. Over a longer 10 week treatment period HH resulted in decreased adverse clinical events.

Background: Indoor air pollution from a range of household cooking fuels has been implicated in the development and exacerbation of respiratory diseases. In both rich and poor countries, the effects of cooking fuels on asthma and allergies in childhood are unclear. We investigated the association between asthma and the use of a range of cooking fuels around the world., Methods: For phase three of the International Study of Asthma and Allergies in Childhood (ISAAC), written questionnaires were self-completed at school by secondary school students aged 13-14 years, 244,734 (78%) of whom were then shown a video questionnaire on wheezing symptoms. Parents of children aged 6-7 years completed the written questionnaire at home. We investigated the association between types of cooking fuels and symptoms of asthma using logistic regression. Adjustments were made for sex, region of the world, language, gross national income, maternal education, parental smoking, and six other subject-specific covariates. The ISAAC study is now closed, but researchers can continue to use the instruments for further research., Findings: Data were collected between 1999 and 2004. 512,707 primary and secondary school children from 108 centres in 47 countries were included in the analysis. The use of an open fire for cooking was associated with an increased risk of symptoms of asthma and reported asthma in both children aged 6-7 years (odds ratio [OR] for wheeze in the past year, 1·78, 95% CI 1·51-2·10) and those aged 13-14 years (OR 1·20, 95% CI 1·06-1·37). In the final multivariate analyses, ORs for wheeze in the past year and the use of solely an open fire for cooking were 2·17 (95% CI 1·64-2·87) for children aged 6-7 years and 1·35 (1·11-1·64) for children aged 13-14 years. Odds ratios for wheeze in the past year and the use of open fire in combination with other fuels for cooking were 1·51 (1·25-1·81 for children aged 6-7 years and 1·35 (1·15-1·58) for those aged 13-14 years. In both age groups, we detected no evidence of an association between the use of gas as a cooking fuel and either asthma symptoms or asthma diagnosis., Interpretation: The use of open fires for cooking is associated with an increased risk of symptoms of asthma and of asthma diagnosis in children. Because a large percentage of the world population uses open fires for cooking, this method of cooking might be an important modifiable risk factor if the association is proven to be causal., Funding: BUPA Foundation, the Auckland Medical Research Foundation, the Health Research Council of New Zealand, the Asthma and Respiratory Foundation of New Zealand, the Child Health Research Foundation, the Hawke's Bay Medical Research Foundation, the Waikato Medical Research Foundation, Glaxo Wellcome New Zealand, the NZ Lottery Board, Astra Zeneca New Zealand, Hong Kong Research Grant Council, Glaxo Wellcome International Medical Affairs., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Eczema is a common chronic disease which has significant morbidity and costs for children and their families. Phase One (1993) of the International Study of Asthma and Allergies in Childhood (ISAAC) found a high prevalence of symptoms of eczema in New Zealand., Objective: In Phase Three (2001-3) we aimed to answer these three questions: Is the prevalence of eczema changing over time?; Are there ethnic differences in prevalence?; and What are the risk factors for eczema?, Methods: Five New Zealand centres participated in ISAAC Phases One and Three using the same methodology. Questionnaires about ethnicity, symptoms of eczema and environmental factors were completed by parents of 6-7 year olds (children) and self-completed by 13-14 year olds (adolescents). Prevalence and change per year were calculated by centre, ethnicity and gender. Prevalence differences between centres and associations with environmental factors were examined using logistic regression., Results: There was little change in prevalence over time for the children, and a decrease in prevalence for the adolescents. Prevalence was higher among Māori and even higher among Pacific participants than among European children. Positive associations with current eczema symptoms were found for both age groups for truck traffic in the street of residence, and current paracetamol consumption, and for children only, antibiotics or paracetamol in the 1st year of life. Inverse associations were found with residence in New Zealand less than 5 years, consumption of milk, seafood, and eggs, and presence of a dog in the home., Conclusion: Eczema remains a significant problem, particularly for young Māori and Pacific New Zealanders in whom less recognition of eczema and poorer access to effective, sustained eczema management may be contributing factors. Reverse causation may explain all the environmental findings apart from truck traffic which is increasing in New Zealand.

Background: Certain foods may increase or decrease the risk of developing asthma, rhinoconjunctivitis and eczema. We explored the impact of the intake of types of food on these diseases in Phase Three of the International Study of Asthma and Allergies in Childhood., Methods: Written questionnaires on the symptom prevalence of asthma, rhinoconjunctivitis and eczema and types and frequency of food intake over the past 12 months were completed by 13-14-year-old adolescents and by the parents/guardians of 6-7-year-old children. Prevalence ORs were estimated using logistic regression, adjusting for confounders, and using a random (mixed) effects model., Results: For adolescents and children, a potential protective effect on severe asthma was associated with consumption of fruit ≥3 times per week (OR 0.89, 95% CI 0.82 to 0.97; OR 0.86, 95% CI 0.76 to 0.97, respectively). An increased risk of severe asthma in adolescents and children was associated with the consumption of fast food ≥3 times per week (OR 1.39, 95% CI 1.30 to 1.49; OR 1.27, 95% CI 1.13 to 1.42, respectively), as well as an increased risk of severe rhinoconjunctivitis and severe eczema. Similar patterns for both ages were observed for regional analyses, and were consistent with gender and affluence categories and with current symptoms of all three conditions., Conclusions: If the association between fast foods and the symptom prevalence of asthma, rhinoconjunctivitis and eczema is causal, then the findings have major public health significance owing to the rising consumption of fast foods globally.

Aim: To investigate prevalence, time trends and factors associated with rhinitis and rhinoconjunctivitis not related to acute infections in New Zealand., Methods: The International Study of Asthma and Allergies in Childhood (ISAAC) surveyed children aged 6-7 and 13-14 years for symptoms of these conditions. Five New Zealand centres were surveyed on two occasions (Phase One and Phase Three) 8-10 years apart. In Phase Three, questions were included on environmental factors, which might be associated with rhinoconjunctivitis. We report findings related to symptoms of rhinoconjunctivitis among 24 190 New Zealand children., Results: Symptoms of rhinoconjunctivitis in the past year were reported in 11.4% of 6- to 7-year-old children and 18% of 13- to 14-year-old adolescents in Phase Three compared with 9.5 and 19.1%, respectively, in Phase One. Severe symptoms of rhinoconjunctivitis were reported in 0.5% of children and 0.8% of adolescents. Current symptoms were more common in males at 6-7 years and in females of 13-14 years, and Māori and Pacific Island ethnic groups had higher prevalence compared with those of European descent, especially in the older age group. For immigrant children, there was a very strong positive relationship between symptoms and length of time resident in New Zealand, supporting the probable importance of environmental factors. A positive association was found between symptoms and use of paracetamol in infancy or in the last year, and weaker associations were noted for antibiotic use, exercise, and regular pasta ingestion., Conclusions: Further study of environmental factors is recommended., (© 2012 The Authors. Journal of Paediatrics and Child Health © 2012 Paediatrics and Child Health Division (Royal Australasian College of Physicians).)

Background: The International Study of Asthma and Allergies in Childhood (ISAAC) identified trends in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema over a seven-year period. We hypothesised that environmental influences on the three diseases are different and therefore investigated the correlation over time between trends in the prevalence of these diseases and their combinations at centre and individual level., Methods: Centre level analyses were correlations between time trends in the prevalence of symptoms. At an individual level, odds ratios were calculated for associations between symptoms between Phases One and Three. We also investigated potential effect modification in the younger versus older age group; male versus female; and by average Gross National Income per capita (GNI)., Results: Both phases were completed in 66 centres in 37 countries for the 6-7 year age group and in 106 centres in 56 countries for the 13-14 year age group. We found that the correlations in time trends were stronger for the older age group than the younger one. Between symptoms of diseases, correlations of time trends were the strongest for rhinoconjunctivitis with eczema and weakest for eczema with asthma. The relationship between the three diseases was generally consistent over the seven-year period, and there was little association found with average GNI., Conclusions: Despite some increase in the proportion of children with symptoms of asthma, rhinoconjunctivitis and eczema, the pattern between the three diseases has not changed much, suggesting that similar factors may be affecting them at a global level., (Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.)

Background: The International Study of Asthma and Allergies in Childhood (ISAAC) used standardised methods to examine symptom prevalence of asthma, rhinitis and eczema in adolescents and children between Phases I and III. Centres followed essential rules to ensure comparability of methodology, examined by a centralised data centre., Methods: Centre reports (CRs) were compared for both phases and age groups. Methodological differences were categorised under major deviations (centres excluded), minor deviations (deviations identified in published tables) and very minor deviations (deviations not identified)., Results: There were 112 CRs for adolescents and 70 for children. Six centres for adolescents and four for children had major deviations and were excluded. Minor deviations (35 for adolescents and 20 for children) were identified in the publications. Very minor deviations (92 for adolescents and 51 for children) were not identified. The odds ratios for having any differences in methodology between phases with a change in Principal Investigator were 0.80 (95%CI 0.36-1.81) for adolescents and 0.91 (95%CI 0.32-2.62) for children., Conclusion: The majority of the centres replicated the ISAAC methodology to a high standard. Careful documentation of methodology using standardised tools with careful checks allows the full potential of studies such as ISAAC to be realised.

The capacity of microbial products to inhibit allergic inflammation make them logical candidates for novel therapies in allergic diseases such as atopic dermatitis. To assess the effects of intradermal Mycobacterium vaccae derivative on allergen-specific immune responses in children with moderate to severe atopic dermatitis. Peripheral blood mononuclear cells were isolated from children aged 5-16 years who received intradermal injections of M. vaccae derivative AVAC(TM) (n = 26) or placebo (n = 34) three times at 2-weekly intervals, weeks 0, 2 and 4. Cytokine [interleukin (IL)-13, interferon (IFN)-γ and IL-10] responses to allergen [house dust mite (HDM)], mitogen [phytohaemagglutinin (PHA)], Staphylococcal enterotoxin B (SEB) and Toll-like receptor (TLR) ligands were assessed. At week 8 (1 month after all injections given) children in the AVAC group showed a significant increase in IL-10 (P = 0·009), T helper type 1 (Th1) IFN-γ (P = 0·017) and Th2 IL-13 (P = 0·004) responses to HDM compared with baseline (week 0). There were no significant changes in any cytokine production in the placebo. HDM-specific IL-10 responses remained significantly higher (P = 0·014) than at baseline in the AVAC group by week 12; however, the HDM-specific IL-13 and IFN-γ responses were no longer significantly different from baseline. IL-13 (r = 0·46, P < 0·001) and IL-10 (r = 0·27, P = 0·044) responses to HDM were correlated with total immunoglobulin E but not with disease severity. There were no effects of AVAC on mitogen, SEB, TLR-2- or TLR-4-mediated responses. This M. vaccae derivative appeared to modulate responses to HDM selectively, suggesting the capacity for in vivo effects on allergen-specific immune responses., (© 2011 Susan L Prescott. Clinical and Experimental Immunology © 2011 British Society for Immunology.)

The intention of this viewpoint article is to prompt discussion and debate about primary health care funding for children under the age of six. While New Zealand offers a superb natural environment for childhood, our child health outcomes continue to be poor, ranking lowest amongst 29 countries in a recent report by the Organisation for Economic Co-operation and Development. Since 1996, various funding arrangements have been introduced with the goal of achieving free primary health care for children under six years of age and nearly 80% of practices now offer care to this group without charge. Universal no cost or very low cost access for young children, however, remains elusive, particularly for after-hours care, and this is important given that at least one in five children lives in poverty. We are under no illusions about the complexity of primary care funding mechanisms and the challenges of supporting financially-sustainable systems of after-hours care. Good health care early in life, however, is a significant factor in producing a healthier and more productive adult population and improving access to primary care lessens the impact of childhood illness. We suggest that reducing cost barriers to primary care access for young children should remain an important target, and recent examples show that further reductions in cost for primary care visits for young children, including after-hours, is possible. Further funding is needed to make this widespread, in conjunction with innovative arrangements between funding authorities, primary care providers, and emergency departments. We encourage further debate on this topic with a view to resolving the question of whether the goal of free child health care for young children in New Zealand can be realised.

Background: Centres in Phases I and III of the International Study of Asthma and Allergies in Childhood (ISAAC) programme used the method of consent (passive or active) required by local ethics committees., Methods: Retrospectively, relationships between achieved response rates and method of consent for 13-14 and 6-7-year-olds (adolescents and children, respectively), were examined between phases and between English and non-English language centres., Results: Information was obtained for 113 of 115 centres for adolescents and 72/72 centres for children. Both age groups: most centres using passive consent achieved high response rates (>80% adolescents and >70% children). English language centres using active consent showed a larger decrease in response rate. Adolescents: seven centres changed from passive consent in Phase I to active consent in Phase III (median decrease of 13%), with five centres showing lower response rates (as low as 34%). Children: no centre changed consent method between phases. Centres using active consent had lower median response rates (lowest response rate 45%)., Conclusion: The requirement for active consent for population school-based questionnaire studies can impact negatively on response rates, particularly English language centres, thus adversely affecting the validity of the data. Ethics committees need to consider this issue carefully.

New research in asthma epidemiology in children includes the development of the ISAAC programme, which has shown large variations globally in the prevalence of asthma symptoms. Time trends in the prevalence of asthma symptoms have shown a mixed picture of increases in low prevalence centres, and a plateau or even a decrease in high prevalence centres. A range of environmental factors have been studied and some potentially protective associations have been found, as well as potentially aggravating factors. Atopy has less influence on the prevalence of symptoms of asthma in low and middle income countries. Breast feeding exerts a protective effect only on non-atopic asthma in non-affluent countries. Future research should explore these areas further., (Copyright 2009 SEICAP. Published by Elsevier Espana. All rights reserved.)