Use of inhaled corticosteroids and the risk of hospitalisation for pneumonia in children with asthma: a nationwide cohort study

BACKGROUND

The potential association between the use of inhaled corticosteroids (ICS) and the risk of pneumonia among adults is disputed and paediatric-specific evidence is scarce.

AIM

To assess the potential association between ICS, use and the risk of hospitalisation for pneumonia among children (age 2-17 years) with asthma.

METHODS

This was a cohort study based on nationwide data from routine clinical practice in Sweden (January 2007 to November 2021). From 425 965 children with confirmed asthma, episodes of new ICS use and no use were identified using records of dispensed drugs. We adjusted for potential confounders with propensity score overlap weighting and the risk of a hospitalisation with pneumonia as primary diagnosis was estimated. Multiple subgroup and sensitivity analyses were also performed.

RESULTS

We identified 249 351 ICS (mean follow-up of 0.9 years) and 214 840 no-use (mean follow-up of 0.7 years) episodes. During follow-up, 369 and 181 events of hospitalisation for pneumonia were observed in the ICS and no-use episodes, respectively. The weighted incidence rates of hospitalisation for pneumonia was 14.5 per 10 000 patient-years for ICS use episodes and 14.6 for no-use episodes. The weighted HR for hospitalisation for pneumonia associated with ICS use was 1.06 (95% CI 0.88 to 1.28) and the absolute rate difference was -0.06 (95% CI -2.83 to 2.72) events per 10 000 patient-years, compared with no use.

CONCLUSIONS

In this nationwide cohort study, we found no evidence of an association between ICS use and the risk of hospitalisation for pneumonia among children with asthma, as compared with no use.

Clinical implications of airway obstruction with normal or low FEV1 in childhood and adolescence

BACKGROUND

Airway obstruction is defined by spirometry as a low forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio. This impaired ratio may originate from a low FEV1 (classic) or a normal FEV1 in combination with a large FVC (dysanaptic). The clinical implications of dysanaptic obstruction during childhood and adolescence in the general population remain unclear.

AIMS

To investigate the association between airway obstruction with a low or normal FEV1 in childhood and adolescence, and asthma, wheezing and bronchial hyperresponsiveness (BHR).

METHODS

In the BAMSE (Barn/Child, Allergy, Milieu, Stockholm, Epidemiology; Sweden) and PIAMA (Prevention and Incidence of Asthma and Mite Allergy; the Netherlands) birth cohorts, obstruction (FEV1:FVC ratio less than the lower limit of normal, LLN) at ages 8, 12 (PIAMA only) or 16 years was classified as classic (FEV1

RESULTS

The prevalence of classic obstruction at ages 8, 12 and 16 in the two cohorts was 1.5%, 1.1% and 1.5%, respectively. Dysanaptic obstruction was slightly more prevalent: 3.9%, 2.5% and 4.6%, respectively. Obstruction, regardless of FEV1, was consistently associated with higher odds of asthma (dysanaptic obstruction: OR 2.29, 95% CI 1.40 to 3.74), wheezing, asthma medication use and BHR compared with the normal lung function group. Approximately one-third of the subjects with dysanaptic obstruction in childhood remained dysanaptic during adolescence.

CLINICAL IMPLICATIONS

Children and adolescents with airway obstruction had, regardless of their FEV1 level, a higher prevalence of asthma and wheezing. Follow-up and treatment at these ages should be guided by the presence of airway obstruction.

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Key Words

• Asthma
• Asthma Epidemiology
• Asthma Guidelines
• Clinical Epidemiology
• Lung Physiology
• Paediatric asthma

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Affiliation(s)

Hans Jacob Lohne Koefoed Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Beatrix Children's Hospital, Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Center Groningen, Groningen, The Netherlands Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, Groningen, The Netherlands
Gang Wang Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Department of Integrated Traditional Chinese and Western Medicine, Sichuan University West China Hospital, Chengdu, Sichuan, China Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
Ulrike Gehring Institute for Risk Assessment Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
Sandra Ekstrom Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden
Inger Kull Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Pediatrics, Sachs' Children's Hospital, Stockholm, Sweden
Roel Vermeulen Institute for Risk Assessment Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
Jolanda M A Boer Center for Nutrition, Prevention, and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
Anna Bergstrom Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden
Gerard H Koppelman Beatrix Children's Hospital, Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Center Groningen, Groningen, The Netherlands Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, Groningen, The Netherlands
Erik Melén Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Pediatrics, Sachs' Children's Hospital, Stockholm, Sweden
Judith M Vonk Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, Groningen, The Netherlands Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
Jenny Hallberg Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden Pediatrics, Sachs' Children's Hospital, Stockholm, Sweden

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Identification and treatment of persistent small airway dysfunction in paediatric patients with asthma: a retrospective cohort study

BACKGROUND

Asthma is a common respiratory disease. In asthma, the small airways have more intensive inflammation and prominent airway remodelling, compared to the central airways. We aimed to investigate the predictive value of risk factors and the fractional concentration of exhaled nitric oxide (FeNO) for persistent small airway dysfunction (p-SAD), and compare the effects of different treatment modalities.

METHODS

This retrospective cohort study included 248 children with asthma (aged 4-11 years). Binary logistic regression was used to analyse the risk factors for p-SAD. Correlations among FEV1/FVC, small airway function parameters, and FeNO levels in patients with asthma were analysed using Spearman's rank correlation. The receiver operating characteristic curve and the Delong test were used to analyse the predictive value of FeNO for p-SAD. Differences in the treatment effects of inhaled corticosteroids (ICS) and ICS with a long-acting beta-agonist (ICS/LABA) on p-SAD were analysed using Fisher's exact test.

RESULTS

Asthmatic children with older age of receiving the regular treatment (OR 1.782, 95% CI 1.082-2.935), with younger age at the time of onset of suspected asthma symptoms (OR 0.602, 95% CI 0.365-0.993), with longer duration of using ICS or ICS/LABA (OR 1.642, 95% CI 1.170-2.305) and with worse asthma control (OR 3.893, 95% CI 1.699-8.922) had increased risk for p-SAD. Significant negative correlations of small airway function parameters with FeNO at a 200 mL/s flow rate (FeNO200), and the concentration of nitric oxide in the alveolar or acinar region (CaNO) were observed. The areas under the curve of FeNO200 (cut-off:10.5ppb), CaNO (cut-off:5.1ppb), and FeNO200 combined with CaNO were 0.743, 0.697, and 0.750, respectively, for asthma with p-SAD. After using ICS or ICS/LABA, switching to ICS/LABA was easier than continuing with ICS to improve small airway dysfunction (SAD) in the 8th month.

CONCLUSIONS

Paediatric asthma with p-SAD is associated with older age at receiving regular treatment, younger age at the time of onset of suspected asthma symptoms, longer duration of using ICS or ICS/LABA, worse asthma control, and higher FeNO200 and CaNO levels, all of which can be combined with small airway function indicators to distinguish p-SAD from asthma. ICS/LABA improves SAD better than ICS alone.

What if… your research is suddenly affiliated with a tobacco manufacturing company?

The tobacco industry is accountable for an annual global death toll of approximately 8 million people and cigarette smoking is the foremost risk factor for several types of cancer. In addition, the tobacco industry has a long and controversial history of trying to influence scientific research and of engaging in other morally problematic practices. In September 2021, the respiratory community was alarmed by the takeover of Vectura Group (Vectura) by Philip Morris International. As a reaction to this acquisition, strict measures were imposed by the International Respiratory Societies to prohibit the involvement of Vectura in respiratory research and its participation in societies' activities. International Respiratory Societies argued that Vectura had become part of the tobacco industry due to this takeover and is, therefore, subject to the same rules and restrictions. From a healthcare and historical perspective, the reaction and imposed measures are very understandable. However, for researchers that were already affiliated with Vectura through long-standing agreements and for research that was funded by Vectura, the imposed measures have serious consequences. With this article, we provide an example of these consequences. By reflecting on this issue, we would like to start a conversation regarding the current measures and to encourage the respiratory community to begin thinking of a way to avoid these consequences in the future. In addition, we hope that with this conversation the Respiratory Societies can set an example for other medical societies on how to cope with possible morally tainted affiliations (eg, fast food companies, alcohol manufacturing companies) in the future.

Influence of age on clinical characteristics, pharmacological management and exacerbations in children with asthma

BACKGROUND

Asthma trials and guidelines often do not distinguish between adolescents and younger children. Using a large English data set, we evaluated the impact of age on asthma characteristics, management and exacerbations.

METHODS

Primary care medical records, 2004-2021, were linked to hospital records. Children were categorised by age at diagnosis and followed until the next age bracket. Ages (based on management guidelines) were 5-8 years, 9-11 years and adolescents (12-16 years). Characteristics evaluated included body mass index, allergies and events before and after diagnosis (symptoms, medication). Exacerbation incidence was calculated. Multivariable Cox proportional hazards determined associations with exacerbations.

RESULTS

119 611 children were eligible: 61 940 (51.8%) 5-8 years, 32 316 (27.7%) 9-11 years and 25 355 (21.2%) adolescents. Several characteristics differed by age; children aged 5-8 years had the highest proportion with eczema, food/drug allergy and cough, but adolescents had the highest proportion with overweight/obesity, aeroallergen sensitisation, dyspnoea and short-acting-beta-agonist only use. Exacerbation rates were highest in the youngest children (per 100 person-years (95% CI): 5-8 years =13.7 (13.4-13.9), 9-11 years =10.0 (9.8-10.4), adolescents =6.7 (6.5-7.0)). Exacerbation risk factors also differed by age; 5-8 years: male, eczema and food/drug allergy were strongly associated, but for children ≥9 years old, obesity and aeroallergen sensitisation were strongly associated. For all children, higher socioeconomic deprivation was significantly associated with having an exacerbation. Delayed diagnosis was most common in children aged 5-8 years and was associated with increased exacerbations across all ages.

CONCLUSION

Children's baseline characteristics and exacerbation rates varied according to their age group. Clinical guidelines should consider age at time of diagnosis more discretely than the broad range, 5-16 years, as this appears to impact on asthma severity and management.

Recent trends in asthma diagnosis, preschool wheeze diagnosis and asthma exacerbations in English children and adolescents: a SABINA Jr study

BACKGROUND

Asthma-related burden remains poorly characterised in children in the UK. We quantified recent trends in asthma prevalence and burden in a UK population-based cohort (1‒17-year-olds).

METHODS

The Clinical Practice Research Datalink Aurum database (2008‒2018) was used to assess annual asthma incidence and prevalence in 1‒17-year-olds and preschool wheeze in 1‒5-year-olds, stratified by sex and age. During the same period, annual asthma exacerbation rates were assessed in those with either a diagnosis of preschool wheeze or asthma.

RESULTS

Annual asthma incidence rates decreased by 51% from 1403.4 (95% CI 1383.7 to 1423.2) in 2008 to 688.0 (95% CI 676.3 to 699.9) per 105 person-years (PYs) in 2018, with the most pronounced decrease observed in 1‒5-year olds (decreasing by 65%, from 2556.9 (95% CI 2509.8 to 2604.7) to 892.3 (95% CI 866.9 to 918.3) per 105 PYs). The corresponding decreases for the 6‒11- and 12‒17-year-olds were 36% (1139.9 (95% CI 1110.6 to 1169.7) to 739.9 (95% CI 720.5 to 759.8)) and 20% (572.3 (95% CI 550.4 to 594.9) to 459.5 (95% CI 442.9 to 476.4)) per 105 PYs, respectively. The incidence of preschool wheeze decreased over time and was slightly more pronounced in the 1‒3 year-olds than in the 4-year-olds. Prevalence of asthma and preschool wheeze also decreased over time, from 18.0% overall in 2008 to 10.2% in 2018 for asthma. Exacerbation rates increased over time from 1.33 (95% CI 1.31 to 1.35) per 10 PYs in 2008 to 1.81 (95% CI 1.78 to 1.83) per 10 PYs in 2018.

CONCLUSION

Paediatric asthma incidence decreased in the UK since 2008, particularly in 1-5-year-olds; this was accompanied by a decline in asthma prevalence. Preschool wheeze incidence also decreased in this age group. However, exacerbation rates have been increasing.

Perinatal and early life factors and asthma control among preschoolers: a population-based retrospective cohort study

BACKGROUND

Preventing poor childhood asthma control is crucial for short-term and long-term respiratory health. This study evaluated associations between perinatal and early-life factors and early childhood asthma control.

METHODS

This retrospective study used administrative health data from mothers and children born 2010-2012 with a diagnosis of asthma before age 5 years, in Alberta, Canada. The outcome was asthma control within 2 years after diagnosis. Associations between perinatal and early-life factors and risk of partly and uncontrolled asthma were evaluated by multinomial logistic regression.

RESULTS

Of 7206 preschoolers with asthma, 52% had controlled, 37% partly controlled and 12% uncontrolled asthma 2 years after diagnosis. Compared with controlled asthma, prenatal antibiotics (adjusted risk ratio (aRR): 1.19; 95% CI 1.06 to 1.33) and smoking (aRR: 1.18; 95% CI 1.02 to 1.37), C-section delivery (aRR: 1.11; 95% CI 1.00 to 1.25), summer birth (aRR: 1.16; 95% CI 1.00 to 1.34) and early-life hospitalisation for respiratory illness (aRR: 2.24; 95% CI 1.81 to 2.76) increased the risk of partly controlled asthma. Gestational diabetes (aRR: 1.41; 95% CI 1.06 to 1.87), C-section delivery (aRR: 1.18; 95% CI 1.00 to 1.39), antibiotics (aRR: 1.32; 95% CI 1.08 to 1.61) and hospitalisation for early-life respiratory illness (aRR: 1.65; 95% CI 1.19 to 2.27) were associated with uncontrolled asthma.

CONCLUSION

Maternal perinatal and early-life factors including antibiotics in pregnancy and childhood, gestational diabetes, prenatal smoking, C-section and summertime birth, and hospitalisations for respiratory illness are associated with partly or uncontrolled childhood asthma. These results underline the significance of perinatal health and the lasting effects of early-life experiences on lung development and disease programming.

Burden and unmet need for specialist care in poorly controlled and severe childhood asthma in a Danish nationwide cohort

BACKGROUND

Asthma is a common disease in childhood and adolescence with lifelong consequences particularly among those at risk of severe disease, poor control and/or frequent exacerbations. Specialist care is recommended for at-risk children and adolescents, yet access to specialist management in free-to-access healthcare settings remains poorly understood.

METHODS

A Danish nationwide cohort of children and adolescents aged 2-17 years with persistent asthma, defined as repeated redemption of inhaled corticosteroids (ICS) during 2015, were followed for two years, to identify at-risk children and adolescents comprising those with severe asthma (classified according to GINA 2020 guidelines), poor control (defined as use of 400/600 (ages 2-11/12 +) annual doses of short-acting bronchodilators), or frequent exacerbations (defined as use of oral steroids or hospitalization), and access to specialist care. The population is chosen due to detailed medical records in the setting of universal health care.

RESULTS

The cohort comprised of 29,851 children and adolescents (59% boys), with a median age of 9 years. While 17% of children were on high dose ICS, 22% were on daily ICS below GINA low dose cut-off. Prevalence of severe asthma (3.0-6.5%) was lower than poor asthma control (6.4-25%); both declined from childhood to adolescence. Exacerbations occurred in 7.1-9.0% of children, with median number of exacerbations being 1 (IQR 1-1). Despite being classified as having mild-to-moderate asthma, 15% had poor asthma control and 3.8% experienced exacerbation(s), respectively. While 61% of children with severe asthma and 58% with exacerbation-prone disease were in specialist care, only 24% with uncontrolled disease were receiving specialist care. Of children and adolescents using high-dose ICS, 71% were managed in primary care, while the use of additional controllers was more common in specialist care.

CONCLUSIONS

Throughout childhood and adolescence, there was a high prevalence of severe asthma and poor control, although their prevalence declined with age. We demonstrate a large unmet need for specialist care among children with at-risk asthma, particularly among those with poorly controlled asthma, even in a system with free-to-access, tax-funded healthcare.

Prevalence, severity and risk factors for asthma in school-going adolescents in KwaZulu Natal, South Africa

BACKGROUND

Asthma remains highly prevalent, with more severe symptoms in low-income to middle-income countries (LMICs) compared with high-income countries. Identifying risk factors for severe asthma symptoms can assist with improving outcomes. We aimed to determine the prevalence, severity and risk factors for asthma in adolescents in an LMIC.

METHODS

A cross-sectional survey using the Global Asthma Network written and video questionnaires was conducted in adolescents aged 13 and 14 from randomly selected schools in Durban, South Africa, between May 2019 and June 2021.

RESULTS

A total of 3957 adolescents (51.9% female) were included. The prevalence of lifetime, current and severe asthma was 24.6%, 13.7% and 9.1%, respectively. Of those with current and severe asthma symptoms; 38.9% (n=211/543) and 40.7% (n=147/361) had doctor-diagnosed asthma; of these, 72.0% (n=152/211) and 70.7% (n=104/147), respectively, reported using inhaled medication in the last 12 months. Short-acting beta agonists (80.4%) were more commonly used than inhaled corticosteroids (13.7%). Severe asthma was associated with: fee-paying school quintile (adjusted OR (CI)): 1.78 (1.27 to 2.48), overweight (1.60 (1.15 to 2.22)), exposure to traffic pollution (1.42 (1.11 to 1.82)), tobacco smoking (2.06 (1.15 to 3.68)), rhinoconjunctivitis (3.62 (2.80 to 4.67)) and eczema (2.24 (1.59 to 3.14)), all p<0.01.

CONCLUSION

Asthma prevalence in this population (13.7%) is higher than the global average (10.4%). Although common, severe asthma symptoms are underdiagnosed and associated with atopy, environmental and lifestyle factors. Equitable access to affordable essential controller inhaled medicines addressing the disproportionate burden of asthma is needed in this setting.

Admixture mapping of severe asthma exacerbations in Hispanic/Latino children and youth

BACKGROUND

In the USA, genetically admixed populations have the highest asthma prevalence and severe asthma exacerbations rates. This could be explained not only by environmental factors but also by genetic variants that exert ethnic-specific effects. However, no admixture mapping has been performed for severe asthma exacerbations.

OBJECTIVE

We sought to identify genetic variants associated with severe asthma exacerbations in Hispanic/Latino subgroups by means of admixture mapping analyses and fine mapping, and to assess their transferability to other populations and potential functional roles.

METHODS

We performed an admixture mapping in 1124 Puerto Rican and 625 Mexican American children with asthma. Fine-mapping of the significant peaks was performed via allelic testing of common and rare variants. We performed replication across Hispanic/Latino subgroups, and the transferability to non-Hispanic/Latino populations was assessed in 1001 African Americans, 1250 Singaporeans and 941 Europeans with asthma. The effects of the variants on gene expression and DNA methylation from whole blood were also evaluated in participants with asthma and in silico with data obtained through public databases.

RESULTS

Genomewide significant associations of Indigenous American ancestry with severe asthma exacerbations were found at 5q32 in Mexican Americans as well as at 13q13-q13.2 and 3p13 in Puerto Ricans. The single nucleotide polymorphism (SNP) rs1144986 (C5orf46) showed consistent effects for severe asthma exacerbations across Hispanic/Latino subgroups, but it was not validated in non-Hispanics/Latinos. This SNP was associated with DPYSL3 DNA methylation and SCGB3A2 gene expression levels.

CONCLUSIONS

Admixture mapping study of asthma exacerbations revealed a novel locus that exhibited Hispanic/Latino-specific effects and regulated DPYSL3 and SCGB3A2.

International perspective on research priorities and outcome measures of importance in the care of children with acute exacerbations of asthma: a qualitative interview study

BACKGROUND

Acute exacerbations of asthma are common in children, however, treatment decisions for severe exacerbations are challenging due to a lack of robust evidence. In order to create more robust research, a core set of outcome measures needs to be developed. In developing these outcomes, it is important to understand the views of clinicians who care for these children in particular, views that relate to outcome measures and research priorities.

METHODS

To determine the views of clinicians, a total of 26 semistructured interviews based on the theoretical domains framework were conducted. These included experienced clinicians from emergency, intensive care and inpatient paediatrics across 17 countries. The interviews were recorded, and later transcribed. All data analyses were conducted in Nvivo by using thematic analysis.

RESULTS

The length of stay in hospital and patient-focused parameters, such as timing to return to school and normal activity, were the most frequently highlighted outcome measures, with clinicians identifying the need to achieve a consensus on key core outcome measure sets. Most research questions focused on understanding the best treatment options, including the role of novel therapies and respiratory support.

CONCLUSION

Our study provides an insight into what research questions and outcome measures clinicians view as important. In addition, information on how clinicians define asthma severity and measure treatment success will assist with methodological design in future trials. The current findings will be used in parallel with a further Paediatric Emergency Research Network study focusing on the child and family perspectives and will contribute to develop a core outcome set for future research.

Wheeze in the time of COVID-19: overcoming obstacles to an unusual diagnosis

This case is an example of a rare cause of a common clinical presentation (persistent lobar collapse with wheeze). We describe patient management from primary care through to a national thoracic referral centre. We highlight the importance of objective testing to support an asthma diagnosis and the need to consider alternative or additional diagnoses if a patient does not respond to treatment or the clinical course is unexpected. We highlight the importance of follow-up X-ray to determine whether atelectasis has resolved, which was significantly delayed in this case due to COVID-19 restrictions. Though rare, an endobronchial tumour should be considered if atelectasis persists and when planning endoscopy for a presumed foreign body, especially if the clinical history and patient factors make a foreign body less likely. Greater awareness of this as a differential may expedite diagnoses for patients in future. We show how virtual, multicentre, multidisciplinary meetings can aid rapid diagnosis, surgical planning and coordination of follow-up across centres.

Impact of lockdowns on paediatric asthma hospital presentations over three waves of COVID-19 pandemic

Public health measures to mitigate the COVID-19 pandemic have altered health care for chronic conditions. The impact of the COVID-19 pandemic on paediatric asthma, the most common chronic respiratory cause of childhood hospitalisation, in Australia, remains unknown. In a multicentre study, we examined the impact of three waves of COVID-19 on paediatric asthma in New South Wales Australia. Time series analysis was performed to determine trends in asthma hospital presentations in children aged 2–17 years before (2015–2019) and during the COVID-19 pandemic (2020–2021) using emergency department and hospital admission datasets from two large tertiary paediatric hospitals.

In this first report from Australia, we observed a significant decrease in asthma hospital presentations during lockdown periods including April (68.85%), May (69.46%), December (49.00%) of 2020 and August (66.59%) of 2021 compared to pre-pandemic predictions.

The decrease in asthma hospital presentations coincided with the lockdown periods during first, second and third waves of the COVID-19 pandemic and was potentially due to reduced transmission of other common respiratory viruses from restricted movement.

At-risk children with asthma (ARC): a systematic review

Introduction

Asthma attacks are responsible for considerable morbidity and may be fatal. We aimed to identify and weight risk factors for asthma attacks in children (5–12 years) in order to inform and prioritise care.

Methods

We systematically searched six databases (May 2016; updated with forward citations January 2017) with no language/date restrictions. Two reviewers independently selected studies for inclusion, assessed study quality and extracted data. Heterogeneity precluded meta-analysis. Weighting was undertaken by an Expert Panel who independently assessed each variable for degree of risk and confidence in the assessment (based on study quality and size, effect sizes, biological plausibility and consistency of results) and then achieved consensus by discussion. Assessments were finally presented, discussed and agreed at a multidisciplinary workshop.

Results

From 16 109 records, we included 68 papers (28 cohort; 4 case-control; 36 cross-sectional studies). Previous asthma attacks were associated with greatly increased risk of attack (ORs between 2.0 and 4.1). Persistent symptoms (ORs between 1.4 and 7.8) and poor access to care (ORs between 1.2 and 2.3) were associated with moderately/greatly increased risk. A moderately increased risk was associated with suboptimal drug regimen, comorbid atopic/allergic disease, African-American ethnicity (USA), poverty and vitamin D deficiency. Environmental tobacco smoke exposure, younger age, obesity and low parental education were associated with slightly increased risk.

Discussion

Assessment of the clinical and demographic features identified in this review may help clinicians to focus risk reduction management on the high-risk child. Population level factors may be used by health service planners and policymakers to target healthcare initiatives.

Trial registration number

CRD42016037464.

Trends in paediatric asthma hospitalisations - differences between neighbouring countries

Paediatric asthma hospitalisation trends in Finland and Sweden over the past 10 years are unclear. We investigated the incidence of paediatric asthma hospitalisations in both countries from 2005 to 2014, using Finland's National Hospital Discharge Register and Sweden's National Patient Register which cover all hospitalisations in the respective countries. During the study period, the incidence of paediatric asthma hospitalisations decreased by 51% in Finland, but remained stable in Sweden. In both countries, asthma hospitalisations decreased over time among children aged 0-4 years, with unclear trends for older ages. The reasons for these intercountry differences are unclear, thus warranting future research.

STAAR: a randomised controlled trial of electronic adherence monitoring with reminder alarms and feedback to improve clinical outcomes for children with asthma

BACKGROUND

Suboptimal adherence to inhaled steroids is common in children with asthma and is associated with poor disease control, reduced quality of life and even death. Previous studies using feedback of electronically monitored adherence data have demonstrated improved adherence, but have not demonstrated a significant impact on clinical outcomes. The aim of this study was to determine whether introduction of this approach into routine practice would result in improved clinical outcomes.

METHODS

Children with asthma aged 6-16 years were randomised to the active intervention consisting of electronic adherence monitoring with daily reminder alarms together with feedback in the clinic regarding their inhaled corticosteroid (ICS) use or to the usual care arm with adherence monitoring alone. All children had poorly controlled asthma at baseline, taking ICS and long-acting β-agonists. Subjects were seen in routine clinics every 3 months for 1 year. The primary outcome was the Asthma Control Questionnaire (ACQ) score. Secondary outcomes included adherence and markers of asthma morbidity.

RESULTS

77 of 90 children completed the study (39 interventions, 38 controls). Adherence in the intervention group was 70% vs 49% in the control group (p≤0.001). There was no significant difference in the change in ACQ, but children in the intervention group required significantly fewer courses of oral steroids (p=0.008) and fewer hospital admissions (p≤0.001).

CONCLUSIONS

The results indicate that electronic adherence monitoring with feedback is likely to be of significant benefit in the routine management of poorly controlled asthmatic subjects.

TRIAL REGISTRATION NUMBER

NCT02451709; pre-result.

Identification of Asthma Subtypes Using Clustering Methodologies

Asthma is a heterogeneous disease comprising a number of subtypes which may be caused by different pathophysiologic mechanisms (sometimes referred to as endotypes) but may share similar observed characteristics (phenotypes). The use of unsupervised clustering in adult and paediatric populations has identified subtypes of asthma based on observable characteristics such as symptoms, lung function, atopy, eosinophilia, obesity, and age of onset. Here we describe different clustering methods and demonstrate their contributions to our understanding of the spectrum of asthma syndrome. Precise identification of asthma subtypes and their pathophysiological mechanisms may lead to stratification of patients, thus enabling more precise therapeutic and prevention approaches.

Tidal changes in respiratory resistance are sensitive indicators of airway obstruction in children

RATIONALE

Individual assessment of airway obstruction in preschool-age children requires sensitive and specific lung function methods with low demand of cooperation. Although the forced oscillation technique (FOT) is feasible in young children, conventional measurements of respiratory impedance (Zrs) have limited diagnostic power in individuals.

OBJECTIVE

To find descriptors of within-breath Zrs that are sensitive indicators of airway obstruction during tidal breathing in children.

METHODS

Zrs was measured with (i) a standard multifrequency FOT (4-26 Hz) to assess the mean values of resistance and reactance for whole breaths and (ii) a 10 Hz signal to track the within-breath changes. Various Zrs measures obtained in healthy children (n=75) and those with acute wheeze (n=31) were investigated with receiver operator characteristic (ROC) analysis. The cut-off values obtained for airway obstruction were then tested in children with recurrent wheeze (n=20) before and after administration of salbutamol.

RESULTS

The largest area under the ROC curve (0.95) was observed for the tidal changes of resistance between the zero-flow values (ΔR). The ΔR cut-off value of 1.42 hPa s/L detected airway obstruction with sensitivity of 92% and specificity of 89% in children with acute wheeze and distinguished children with recurrent wheeze (16/20 above the cut-off value) from healthy children (22/23 below the cut-off value). Furthermore, ΔR significantly decreased after salbutamol in wheezy children but remained unchanged in healthy children.

CONCLUSIONS

New lung function measure ΔR is able to detect airway obstruction with high sensitivity and specificity and is suitable for use in lung function testing in young children.

Cost-effectiveness of FENO-based and web-based monitoring in paediatric asthma management: a randomised controlled trial

BACKGROUND

In children with asthma, web-based monitoring and inflammation-driven therapy may lead to improved asthma control and reduction in medications. However, the cost-effectiveness of these monitoring strategies is yet unknown.

OBJECTIVE

We assessed the cost-effectiveness of web-based monthly monitoring and of 4-monthly monitoring of FENO as compared with standard care.

METHODS

An economic evaluation was performed alongside a randomised controlled multicentre trial with a 1-year follow-up. Two hundred and seventy-two children with asthma, aged 4-18 years, were randomised to one of three strategies. In standard care, treatment was adapted according to Asthma Control Test (ACT) at 4-monthly visits, in the web-based strategy also according to web-ACT at 1 month intervals, and in the FENO-based strategy according to ACT and FENO at 4-monthly visits. Outcome measures were patient utilities, healthcare costs, societal costs and incremental cost per quality-adjusted life year (QALY) gained.

RESULTS

No statistically significant differences were found in QALYs and costs between the three strategies. The web-based strategy had 77% chance of being most cost-effective from a healthcare perspective at a willingness to pay a generally accepted €40 000/QALY. The FENO-based strategy had 83% chance of being most cost-effective at €40 000/QALY from a societal perspective.

CONCLUSIONS

Economically, web-based monitoring was preferred from a healthcare perspective, while the FENO-based strategy was preferred from a societal perspective, although in QALYs and costs no statistically significant changes were found as compared with standard care. As clinical outcomes also favoured the web-based and FENO-based strategies, these strategies may be useful additions to standard care.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register (NTR1995).

Gastro-oesophageal reflux and worse asthma control in obese children: a case of symptom misattribution?

BACKGROUND

Obese children for unknown reasons report greater asthma symptoms. Asthma and obesity both independently associate with gastro-oesophageal reflux symptoms (GORS). Determining if obesity affects the link between GORS and asthma will help elucidate the obese-asthma phenotype.

OBJECTIVE

Extend our previous work to determine the degree of associations between the GORS and asthma phenotype.

METHODS

We conducted a cross-sectional study of lean (20%-65% body mass index, BMI) and obese (≥95% BMI) children aged 10-17 years old with persistent, early-onset asthma. Participants contributed demographics, GORS and asthma questionnaires and lung function data. We determined associations between weight status, GORS and asthma outcomes using multivariable linear and logistic regression. Findings were replicated in a second well-characterised cohort of asthmatic children.

RESULTS

Obese children had seven times higher odds of reporting multiple GORS (OR=7.7, 95% CI 1.9 to 31.0, interaction p value=.004). Asthma symptoms were closely associated with GORS scores in obese patients (r=0.815, p<0.0001) but not in leans (r=0.291, p=0.200; interaction p value=0.003). Higher GORS scores associated with higher FEV1-per cent predicted (p=0.003), lower airway resistance (R10, p=0.025), improved airway reactance (X10, p=0.005) but significantly worse asthma control (Asthma Control Questionnaire, p=0.007). A significant but weaker association between GORS and asthma symptoms was seen in leans compared with obese in the replicate cohort.

CONCLUSION

GORS are more likely to associate with asthma symptoms in obese children. Better lung function among children reporting gastro-oesophageal reflux and asthma symptoms suggests that misattribution of GORS to asthma may be a contributing mechanism to excess asthma symptoms in obese children.

Getting the basics right resolves most cases of uncontrolled and problematic asthma

AIM

The prevalence of true therapy-resistant asthma among children whose asthma remains uncontrolled, despite daily controller therapy, is unknown. The aim of this study was to investigate the underlying causes in children with uncontrolled asthma.

METHODS

This was a retrospective chart review of 142 children aged from five to 17 years over a five-year period. The patients had uncontrolled asthma and were referred by general practitioners to a hospital-based paediatric asthma clinic.

RESULTS

An underlying cause for uncontrolled asthma was found in 138 children (97.2%). The causes were poor adherence (n = 53, 37.3%), ongoing exposure to environmental triggers (n = 40, 28.2%), comorbidities (n = 28, 19.7%), incorrect inhaler technique (n = 11, 7.7%) and incorrect diagnosis (n = 6, 4.2%). After properly addressing these basics in asthma management, the asthma was well controlled in all 138 patients and lung function was normal. Only four children (2.8%) fulfilled the criteria for true therapy-resistant asthma.

CONCLUSION

A remedial cause in the basics of asthma management could be found in 97% of children with uncontrolled asthma referred to a hospital-based asthma clinic. True therapy-resistant asthma was found to be very rare in children.

Breastfeeding, lung volumes and alveolar size at school-age

Background

Previous studies found larger lung volumes at school-age in formerly breastfed children, with some studies suggesting an effect modification by maternal asthma. We wanted to explore this further in children who had undergone extensive lung function testing. The current study aimed to assess whether breastfeeding was associated with larger lung volumes and, if so, whether all compartments were affected. We also assessed association of breastfeeding with apparent diffusion coefficient (ADC), which measures freedom of gas diffusion in alveolar-acinar compartments and is a surrogate of alveolar dimensions. Additionally, we assessed whether these effects were modified by maternal asthma.

Methods

We analysed data from 111 children and young adults aged 11–21 years, who had participated in detailed lung function testing, including spirometry, plethysmography and measurement of ADC of ³Helium (³He) by MR. Information on breastfeeding came from questionnaires applied in early childhood (age 1–4 years). We determined the association between breastfeeding and these measurements using linear regression, controlling for potential confounders.

Results

We did not find significant evidence for an association between duration of breastfeeding and lung volumes or alveolar dimensions in the entire sample. In breastfed children of mothers with asthma, we observed larger lung volumes and larger average alveolar size than in non-breastfed children, but the differences did not reach significance levels.

Conclusions

Confirmation of effects of breastfeeding on lung volumes would have important implications for public health. Further investigations with larger sample sizes are warranted.

Asthma in Latin America

Consistent with the diversity of Latin America, there is profound variability in asthma burden among and within countries in this region. Regional variation in asthma prevalence is likely multifactorial and due to genetics, perinatal exposures, diet, obesity, tobacco use, indoor and outdoor pollutants, psychosocial stress and microbial or parasitic infections. Similarly, non-uniform progress in asthma management leads to regional variability in disease morbidity. Future studies of distinct asthma phenotypes should follow-up well-characterised Latin American subgroups and examine risk factors that are unique or common in Latin America (eg, stress and violence, parasitic infections and use of biomass fuels for cooking). Because most Latin American countries share the same barriers to asthma management, concerted and multifaceted public health and research efforts are needed, including approaches to curtail tobacco use, campaigns to improve asthma treatment, broadening access to care and clinical trials of non-pharmacological interventions (eg, replacing biomass fuels with gas or electric stoves).

The Canadian Healthy Infant Longitudinal Development (CHILD) Study: examining developmental origins of allergy and asthma

The Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort study recruited 3624 pregnant women, most partners and 3542 eligible offspring. We hypothesise that early life physical and psychosocial environments, immunological, physiological, nutritional, hormonal and metabolic influences interact with genetics influencing allergic diseases, including asthma. Environmental and biological sampling, innate and adaptive immune responses, gene expression, DNA methylation, gut microbiome and nutrition studies complement repeated environmental and clinical assessments to age 5. This rich data set, linking prenatal and postnatal environments, diverse biological samples and rigorous phenotyping, will inform early developmental pathways to allergy, asthma and other chronic inflammatory diseases.

Asthma-COPD overlap 2015: now we are six

BACKGROUND

The overlap between asthma and COPD is increasingly recognised. This review examines the new insights, treatment and remaining knowledge gaps for asthma-COPD overlap.

METHOD

A systematic literature review of cluster analyses of asthma and COPD was performed. Articles from 2009 to the present dealing with prevalence, morbidity and treatment of asthma-COPD overlap were identified and reviewed.

RESULTS

Asthma-COPD overlap was consistently recognised in studies using a variety of different study designs and sampling. The prevalence was approximately 20% in patients with obstructive airways diseases. Asthma-COPD overlap was associated with increased morbidity and possibly an increased mortality and comorbidity. There was evidence of a heterogeneous pattern of airway inflammation that included eosinophilic (in adult asthma), neutrophilic or mixed patterns (in severe asthma and COPD). Systemic inflammation was present in asthma-COPD overlap and resembled that of COPD. Within asthma-COPD overlap, there is evidence of different subgroups, and recognition using bronchodilator responsiveness has not been successful. Guidelines generally recommend a serial approach to assessment, with treatment recommendations dominated by an asthma paradigm. Research is needed into key clinical features that impact outcome, mechanisms and treatment approaches in asthma-COPD overlap. Identifying and treating disease components by multidimensional assessment shows promise.

CONCLUSIONS

Asthma-COPD overlap has drawn attention to the significant heterogeneity that exists within obstructive airway diseases. It should be replaced by novel approaches that identify and manage the components of this heterogeneity, such as multidimensional assessment and treatment. Future research is needed to test these novel and personalised approaches.

Perinatal paracetamol exposure in mice does not affect the development of allergic airways disease in early life

Background

Current data concerning maternal paracetamol intake during pregnancy, or intake during infancy and risk of wheezing or asthma in childhood is inconclusive based on epidemiological studies. We have investigated whether there is a causal link between maternal paracetamol intake during pregnancy and lactation and the development of house dust mite (HDM) induced allergic airways disease (AAD) in offspring using a neonatal mouse model.

Methods

Pregnant mice were administered paracetamol or saline by oral gavage from the day of mating throughout pregnancy and/or lactation. Subsequently, their pups were exposed to intranasal HDM or saline from day 3 of life for up to 6 weeks. Assessments of airway hyper-responsiveness, inflammation and remodelling were made at weaning (3 weeks) and 6 weeks of age.

Results

Maternal paracetamol exposure either during pregnancy and/or lactation did not affect development of AAD in offspring at weaning or at 6 weeks. There were no effects of maternal paracetamol at any time point on airway remodelling or IgE levels.

Conclusions

Maternal paracetamol did not enhance HDM induced AAD in offspring. Our mechanistic data do not support the hypothesis that prenatal paracetamol exposure increases the risk of childhood asthma.

Monitoring strategies in children with asthma: a randomised controlled trial

BACKGROUND

Asthma guidelines recommend monitoring of asthma control. However, in a substantial proportion of children, asthma is poorly controlled and the best monitoring strategy is not known.

OBJECTIVES

We studied two monitoring strategies for their ability to improve asthma outcomes in comparison with standard care (SC): web-based monthly monitoring with the (Childhood) Asthma Control Test (ACT or C-ACT) and 4-monthly monitoring of FENO.

METHODS

In this randomised controlled, partly blinded, parallel group multicentre trial with a 1-year follow-up, children aged 4-18 with a doctor's diagnosis of asthma treated in seven hospitals were randomised to one of the three groups. In the web group, treatment was adapted according to ACT obtained via a website at 1-month intervals; in the FENO group according to ACT and FENO, and in the SC group according to the ACT at 4-monthly visits. The primary endpoint was the change from baseline in the proportion of symptom-free days (SFD).

RESULTS

Two-hundred and eighty children (mean age 10.4 years, 66% boys) were included; 268 completed the study. Mean changes from baseline in SFD were similar between the groups: -2.1% (web group, n=90), +8.9% (FENO group, n=91) versus 0.15% (SC, n=87), p=0.15 and p=0.78. Daily dose of inhaled corticosteroids (ICS) decreased more in the web-based group compared with both other groups (-200 μg/day, p<0.01), while ACT and SFD remained similar.

CONCLUSIONS

The change from baseline in SFD did not differ between monitoring strategies. With web-based ACT monitoring, ICS could be reduced substantially while control was maintained.

TRIAL REGISTRATION NUMBER

NTR 1995.

The Study Team for Early Life Asthma Research (STELAR) consortium 'Asthma e-lab': team science bringing data, methods and investigators together

We created Asthma e-Lab, a secure web-based research environment to support consistent recording, description and sharing of data, computational/statistical methods and emerging findings across the five UK birth cohorts. The e-Lab serves as a data repository for our unified dataset and provides the computational resources and a scientific social network to support collaborative research. All activities are transparent, and emerging findings are shared via the e-Lab, linked to explanations of analytical methods, thus enabling knowledge transfer. eLab facilitates the iterative interdisciplinary dialogue between clinicians, statisticians, computer scientists, mathematicians, geneticists and basic scientists, capturing collective thought behind the interpretations of findings.

Developmental determinants in non-communicable chronic diseases and ageing

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Which intravenous bronchodilators are being administered to children presenting with acute severe wheeze in the UK and Ireland?

During a prospective 10-week assessment period, 3238 children aged 1-16 years presented with acute wheeze to Paediatric Emergency Research in the UK and Ireland centres. 110 (3.3%) received intravenous bronchodilators. Intravenous magnesium sulfate (MgSO4) was used in 67 (60.9%), salbutamol in 61 (55.5%) and aminophylline in 52 (47.3%) of cases. In 35 cases (31.8%), two drugs were used together, and in 18 cases (16.4%), all three drugs were administered. When used sequentially the most common order was salbutamol, then MgSO4, then aminophylline. Overall, 30 different intravenous treatment regimens were used varying in drugs, dose, rate and duration.

A longitudinal study of lung function from 1 month to 18 years of age

BACKGROUND

Our hypothesis was that factors associated with wheeze will be associated with changes in lung function trajectory between 1 month and 18 years of age.

METHODS

Measurements of lung function were made in individuals aged 1, 6 and 12 months (V'maxFRC), and also at ages 6, 12 and 18 years (FEF(25-75)). Changes in lung function over time relative to sex, a history of asthma, maternal asthma and other factors were explored using random coefficient models.

RESULTS

Lung function (maximal flow at functional residual capacity in infants and FEF(25-75) in children) was determined in 241 individuals at 1 month, 192 at 6 months, 164 at 12 months, 106 at 6 years, 183 at 12 years and 141 at 18 years. In the multivariable model, maternal asthma (mean reduction in lung function 9.8%), flow limitation (mean reduction 17.4%), infant atopy (mean reduction 12.6%) and maternal smoking (mean reduction in lung function 8.1%) were acting independently. When interactions with time were sought, the reduction in lung function associated with maternal asthma and infant atopy were consistent over time, but % lung function increased in boys by a mean of 1%/year compared with girls, in flow-limited individuals by 3.0%/year and by 0.9%/year for those exposed to maternal smoking during pregnancy compared to other cohort members.

CONCLUSIONS

Decrements in lung function in 18-year-olds associated with maternal asthma and early onset atopy may be determined by 1 month of age. Low initial lung function in some individuals can 'recover' in some settings.