Worldwide time trends in prevalence of symptoms of rhinoconjunctivitis in children: Global Asthma Network Phase I.

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 Phases 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: 27 GAN centres in 14 countries surveyed 74,361 13-14-year-olds ("adolescents") and 45,434 6-7-year-olds ("children"), with average response proportions of 90% and 79% respectively. Many centres showed highly significant (p<0.001) changes in prevalence of rhinoconjunctivitis in the past year ("current rhinoconjunctivitis"), compared to ISAAC. The direction and magnitude of centre-level trends varied significantly (p<0.001) 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; -0.44% [-1.29%, +0.42%] among children. Together, these differed significantly (p<0.001) 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<0.0001) but not with centre-level trends in asthma symptoms (rho=0.15, p=0.48). 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

The burden of asthma, hay fever and eczema in children in 25 countries: GAN Phase I study

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

Asthma management and control in children, adolescents and adults: Global Asthma Network (GAN) Phase I cross-sectional study

Background Asthma is one of the most common non-communicable diseases. This study aimed to obtain information on asthma management and control in different country settings. Methods A validated questionnaire, including asthma medicines use, was filled in through schools, in three age groups (6-7, 13-14 years, and adults) from 63 centres in 25 countries. Severity and control of asthma was defined from specific questions. Gross National Income (GNI) followed World Bank classification. Proportions (and their 95%CI clustered by centre) were used to describe results. Generalised structural equation multilevel models were used to assess factors associated to receiving medicines or having uncontrolled asthma. Findings Overall, 453,473 individuals (101,777 children, 157,784 adolescents, 193,912 adults) were included; and 6·3%, 7·9%, and 3·4%, respectively, had doctor-diagnosed asthma. Medicines use varied across symptom severity and GNI. Inhaled short-acting beta2-agonists (SABA) (range 29·3%-85·3%) and corticosteroids (ICS) (range 12·6%-51·9%) were most used. The proportion of those with severe asthma symptoms not taking ICS was 44.8% in children, 60·1% in adolescents, and 55·5% in adults and was higher in centres in the lower GNI categories. Oral SABA and theophylline were widely used. Asthma management plans were used by 62·8%, 53·4% and 47·4% of children, adolescents, and adults, respectively; and 44·1%, 55·4% and 61·1% had well controlled asthma. Poor asthma control was associated with lower GNI. Interpretation Asthma management and control is commonly poor and particularly so in low resource settings. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective, affordable asthma care

Asthma management and control in children, adolescents, and adults in 25 countries: a Global Asthma Network Phase I cross-sectional study

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

Asthma management and control in children, adolescents, and adults in 25 countries: a Global Asthma Network Phase I cross-sectional study.

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

The burden of asthma, hay fever and eczema in adults in 17 countries: GAN Phase I study

Asthma, hay fever and eczema are three common chronic conditions. There are 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. The Global Asthma Network (GAN) 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 (ISAAC) Phase III. It provides data on the burden of asthma, hay fever, and eczema not only in children and adolescents but also for the first time in their parents/guardians. Data were available from 193,912 adults (104,061 female; mean age 38 (SD 7·5)) in 43 centres in 17 countries. The overall prevalences (range) of symptoms of current wheeze, asthma ever, hay fever ever and eczema ever were 6·6% (0·9% -32·7%), 4·4%(0·9% -29·0%), 14·4%(2·8%-45·7%), and 9·9%(1.6%-29.5%), respectively. 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. We found evidence for a substantial burden of asthma, hay fever ever and eczema ever in 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

Trends in eczema prevalence in children and adolescents: A Global Asthma Network Phase One Study

Background: Eczema (atopic dermatitis) is a major global public health issue with high prevalence and morbidity. Our goal was to see if eczema prevalence had stopped increasing, using standardised methodology. Methods: The Global Asthma Network (GAN) Phase I study is an international collaborative study arising from the International Study of Asthma and Allergies in Children (ISAAC). Using surveys we assessed eczema prevalence, severity and lifetime prevalence, in global centres participating in GAN Phase I (2015-2020) and one/ both of ISAAC Phase I (1993-1995) and Phase III (2001-3). We fitted linear mixed models to estimate ten-yearly prevalence trends, by age group, income and region. Results: We analysed GAN Phase I data from 27 centres in 14 countries involving 74,361 adolescents aged 13-14 and 47,907 children aged 6-7 (response rate 90%, 79%). A median of 6% of children and adolescents had symptoms of current eczema, with 1.1 and 0.6% in adolescents and children respectively reporting symptoms of severe eczema. Over 27 years, after adjusting for world region and income, we estimated small overall 10-year increases in current eczema prevalence (adolescents: 0.98%, 95% CI 0.04%-1.92%; children: 1.21%, 95% CI 0.18%-2.24%), and severe eczema (adolescents: 0.26%, 95% CI 0.06%-0.46%; children: 0.23%, 95% CI 0.02%-0.45%) with larger increases in lifetime prevalence (adolescents: 2.71%, 95% CI 1.10%-4.32%; children: 3.91%, 95% CI 2.07%-5.75%). There was substantial heterogeneity in 10-year change between centres (standard deviations 2.40, 0.58 and 3.04%), and strong evidence that some of this heterogeneity was explained by region and income level. Conclusions: There is substantial variation in changes in eczema prevalence over time by income and region. Understanding reasons for increases in some regions and decreases in others will help inform prevention