The Global Asthma Network rationale and methods for Phase I global surveillance: prevalence, severity, management and risk factors.

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.

Ethnic and socio-economic differences in the prevalence of wheeze, severe wheeze, asthma, eczema and medication usage at 4 years of age: Findings from the Born in Bradford birth cohort.

BACKGROUND: Asthma, wheeze and eczema are common in early childhood and cause considerable morbidity. Generally rates of these conditions are higher in high income compared to low income countries. Rates in developed nations are generally higher than in less developed countries. After migration to Western countries, differences in risks of developing these conditions may between migrant and non-migrant may diminish. METHODS: A convenience sample of 1648 children of White British, Pakistani or Other ethnicity aged between 4 and 5 years were recruited from the main Born in Bradford cohort. Children's parents or guardians were asked to report on a range of potential risk factors and their associations with wheeze, asthma and eczema. Relationships between ethnicity and disease outcomes were examined using logistic regression after adjustment for other relevant risk factors and confounders. RESULTS: Ethnic differences in doctor diagnosed asthma were evident, with children of other ethnic Origin being less likely and children of Pakistani origin more likely to have a diagnosis than White British or other origin children, although after adjustment for other risk factors this difference only remained significant for the Other Ethnic group. Ethnic differences were not observed in other outcomes including wheeze in the past 12 months, severe wheeze and taking medications for breathing problems. CONCLUSIONS: In UK born children, traditional risk factors such as gender, family history, socio-economic status and child's medical history may be stronger risk factors than ethnicity or familial migration patterns.

Incidence and Burden of Wheezing Disorders, Eczema, and Rhinitis in Children: findings from the Born in Bradford Cohort.

BACKGROUND: Bradford city has high infant mortality and there is a major health concern in the community due to environmental pollution. The aim of the study was to investigate the incidence and burden of wheezing disorders, eczema, and rhinitis in children aged 3-7 years . METHODS: It is a prospective cohort study; the participants were 13 734 children from the Born in Bradford cohort. RESULTS: There were a total of 22.1% (95% Confidence Interval (CI) 21.4, 22.8%), 52.4% (95% CI 51.5%, 53.2%), and 19.3% (95% CI 18.6, 19.9%) incidence cases of wheezing disorders, eczema, and rhinitis respectively. A total of 37% (95% CI 36.2%, 37.8%), 19.5% (95% CI 18.9%, 20.2%,) and 5.9% (95% CI 5.5%, 6.3%) of the children were affected by only one, two, and three diseases respectively. Boys to girls incidence rate ratios for wheezing disorders, eczema, and rhinitis was 1.41 (95% CI 1.31, 1.51), 1.02 (95% CI 0.97, 1.07), and 1.18 (95% CI 1.09, 1.28) respectively. The respective incidence rate ratios of Pakistani to White British were 0.94 (95% CI 0.87, 1.02), 1.31 (95% CI 1.24, 1.39), and 2.03 (95% CI 1.83, 2.25) respectively. CONCLUSION: This study shows that the burden of wheezing disorders, eczema, and rhinitis in this cohort is higher than previously reported in earlier studies. In addition, it indicates that while boys are more likely to suffer from wheezing disorders, rhinitis, and multiple diseases than girls, Pakistani children are more likely to suffer from eczema, rhinitis, and multiple diseases than White British children.