Fifty years of pediatric asthma in developed countries: how reliable are the basic data sources?

High-Flow Humidified Oxygen as an Early Intervention in Children With Acute Severe Asthma: Protocol for a Feasibility Randomized Controlled Trial

BACKGROUND

Acute severe asthma (ASA) is a leading cause of hospital attendance in children. Standard first-line therapy consists of high-dose inhaled bronchodilators plus oral corticosteroids. Treatment for children who fail to respond to first-line therapy is problematic: the use of intravenous agents is inconsistent, and side effects are frequent. High-flow humidified oxygen (HiFlo) is widely used in respiratory conditions and is increasingly being used in ASA, but with little evidence for its effectiveness. A well-designed, adequately powered randomized controlled trial (RCT) of HiFlo therapy in ASA is urgently needed, and feasibility data are required to plan such an RCT. In this study, we describe the protocol for a feasibility study designed to fill this knowledge gap.

OBJECTIVE

This study aims to establish whether a full RCT of early HiFlo therapy in children with ASA can be conducted successfully and safely, to establish whether recruitment using deferred consent is practicable, and to define appropriate outcome measures and sample sizes for a definitive RCT. The underlying hypothesis is that early HiFlo therapy in ASA will reduce the need for more invasive treatments, allow faster recovery and discharge from hospital, and in both these ways reduce distress to children and their families.

METHODS

We conducted a feasibility RCT with deferred consent to assess the use of early HiFlo therapy in children aged 2 to 11 years with acute severe wheeze not responding to burst therapy (ie, high-dose inhaled salbutamol with or without ipratropium). Children with a Preschool Respiratory Assessment Measure score ≥5 after burst therapy were randomized to commence HiFlo therapy or follow standard care. The candidate primary outcomes assessed were treatment failure requiring escalation and time to meet hospital discharge criteria. Patient and parent experiences were also assessed using questionnaires and telephone interviews.

RESULTS

The trial was opened to recruitment in February 2020 but was paused for 15 months owing to the COVID-19 pandemic. The trial was reopened at the lead site in July 2021 and opened at the other 3 sites from August to December 2022. Recruitment was completed in June 2023.

CONCLUSIONS

This feasibility RCT of early HiFlo therapy in children with ASA recruited to the target despite major disturbances owing to the COVID-19 pandemic. The data are currently being analyzed and will be published separately.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Registry ISRCTN78297040; https://www.isrctn.com/ISRCTN78297040.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54081.

Trends in worldwide asthma prevalence

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.

Obesity and childhood asthma

PURPOSE OF REVIEW

Asthma is a common chronic disease of the airways characterized by recurrent respiratory symptoms, bronchoreactivity, and airway inflammation. The high toll on quality of life has led to sustained efforts to understand the factors leading to asthma inception and poor disease control. Obesity is another increasingly common pediatric disease, which appears to increase the risk for incident asthma and worsened disease severity. Currently, our understanding of how obesity affects asthma risk and affects its phenotypic characteristics remains incomplete. The current review describes our current understanding of the epidemiology, clinical characteristics, and management considerations of obesity-related asthma in children.

RECENT FINDINGS

The epidemiologic relationship between obesity in children and incident asthma remains confusing despite numerous longitudinal cohort studies, and appears to be influenced by early life exposures, patterns of somatic growth and underlying familial risks of allergic disease. Children with comorbid obesity and asthma demonstrate diverse phenotypic characteristics which are still becoming clear.

SUMMARY

Like any child with asthma, a child with comorbid obesity requires an individualized approach adhering to current best-practice guidelines and an understanding of how obesity and asthma may interact.

Does discharging asthma patients after one hour of treatment if clinically well affect emergency department length of stay

AIM

Asthma is a major contributor to direct and indirect health-care costs and resource use. In May 2015, the Royal Children's Hospital (RCH) amended its clinical practice guideline for acute asthma management from discharging patients if the anticipated salbutamol requirement was every 3-4 h to discharging patients who were clinically well at 1 h after initial treatment. Our objective was to examine the impact of the new discharge recommendation on emergency department (ED) length of stay (LOS), rates of admission and representation.

METHODS

We retrospectively audited the case notes of children presenting with mild or moderate asthma to the RCH ED over the equivalent 2-week periods in winter 2014 (pre-implementation of the new guideline) and 2015 (post-implementation).

RESULTS

A total of 105 patients in 2014 and 92 patients in 2015 were included. In both years, all patients who initially presented with mild or moderate asthma either improved or stayed within the same severity classification at the 1-h assessment. For patients who were clinically well by the 1-h assessment, there was a significant reduction in admissions between 2014 and 2015 (40 vs. 10%, P = 0.001). There was also a reduction for these patients in median LOS from 3 h 13 min in 2014 to 2 h 31 min in 2015 (P = 0.03). In both years, all patients who were moderate at 1 h were admitted. There was no difference in the rate of representation or subsequent deterioration in those patients who were discharged at 1 h between the 2 years.

CONCLUSION

Early discharge of patients who are clinically well 1 h after initial therapy may be associated with a reduction in LOS and admission rate without an apparent compromise in patient safety. Further evaluation of this intervention is required to determine whether this is a true causal relationship.

Being Overweight or Obese and the Development of Asthma

OBJECTIVES

Adult obesity is linked to asthma cases and is estimated to lead to 250 000 new cases yearly. Similar incidence and attributable risk (AR) estimates have not been developed for children. We sought to describe the relationship between overweight and obesity and incident asthma in childhood and quantify AR statistics in the United States for overweight and obesity on pediatric asthma.

METHODS

The PEDSnet clinical data research network was used to conduct a retrospective cohort study (January 2009-December 2015) to compare asthma incidence among overweight and/or obese versus healthy weight 2- to 17-year-old children. Asthma incidence was defined as ≥2 encounters with a diagnosis of asthma and ≥1 asthma controller prescription. Stricter diagnostic criteria involved confirmation by spirometry. We used multivariable Poisson regression analyses to estimate incident asthma rates and risk ratios and accepted formulas for ARs.

RESULTS

Data from 507 496 children and 19 581 972 encounters were included. The mean participant observation period was 4 years. The adjusted risk for incident asthma was increased among children who were overweight (relative risk [RR]: 1.17; 95% confidence interval [CI]: 1.10-1.25) and obese (RR: 1.26; 95% CI: 1.18-1.34). The adjusted risk for spirometry-confirmed asthma was increased among children with obesity (RR: 1.29; 95% CI: 1.16-1.42). An estimated 23% to 27% of new asthma cases in children with obesity is directly attributable to obesity. In the absence of overweight and obesity, 10% of all cases of asthma would be avoided.

CONCLUSIONS

Obesity is a major preventable risk factor for pediatric asthma.

Trends in asthma hospital admissions and mortality in Kuwait, 2000-2014: a national retrospective observational study

OBJECTIVES

To examine trends in asthma hospitalisation and mortality rates from 2000 to 2014 in Kuwait according to sex, age and nationality.

METHODS

For this nationwide, retrospective observational study, data from hospital discharge records and death certificates listing asthma as the primary reason for hospitalisation or mortality were obtained from the National Center for Health Information database using International Classification of Diseases, Tenth Revision codes J45 and J46. Trends in sex-adjusted, age-adjusted and nationality-adjusted hospitalisation and mortality rates were examined. Poisson regression models were applied to test for linear trends overtime and estimate adjusted rate ratios and 95% CI.

RESULTS

During the 15-year study period, a total of 43 652 hospitalisations and 484 deaths due to asthma exacerbations were identified. The average annual adjusted rates of asthma hospitalisation and mortality were estimated to be 134.9 (95% CI 131.8 to 138.1) and 2.1 (95% CI 1.8 to 2.4) per 100 000 population, respectively. Hospitalisation rates decreased by 49.5% in the total population (from 180.8 to 91.3 admissions per 100 000 population between 2000 and 2014, ptrend <0.001) and by 57.9% in the age group of 5-44 years (from 77.3 to 32.5 admissions per 100 000 population, ptrend <0.001). Mortality rates decreased from 4.1 to 0.9 deaths per 100 000 population between 2000 and 2014 in the total population (77.6% decrease, ptrend <0.001) and from 0.6 to 0.2 deaths per 100 000 population among those aged 5-44 years (61.9% reduction, ptrend=0.005). Kuwaiti compared with non-Kuwaiti subjects had higher risk of asthma hospitalisation and mortality. Among children aged ≤19 years, the risk of hospitalisation was higher in boys compared with girls; however, among adults, women experienced more hospitalisations than men.

CONCLUSIONS

Asthma hospitalisation and mortality rates have substantially decreased between 2000 and 2014 in Kuwait, with persisting differences between genders, age groups and citizens versus non-citizens. The observed decreasing trends in Kuwait are in agreement with global trends.

Residential greenness and allergic respiratory diseases in children and adolescents - A systematic review and meta-analysis

BACKGROUND

The aetiology of allergic respiratory disease in children is not yet fully understood. Environmental factors are believed to play a major part. The amount of green vegetation surrounding the home (residential greenness) has been recently identified as a potentially important exposure OBJECTIVES: Our goal was to provide a systematic review and quantitative summary of the evidence regarding the relationship between residential greenness and allergic respiratory diseases in children.

METHODS

Peer-reviewed literature published prior to 1 March 2017 was systematically searched using nine electronic databases. Meta-analyses were conducted if at least three studies published risk estimates for the same outcome and exposure measures.

RESULTS

We included 11 articles across broad outcomes of asthma and allergic rhinitis. Reported effects were inconsistent with varying measures to define residential greenness. Only limited meta-analysis could be conducted, with the pooled odds ratios for asthma (OR 1.01 95%CI 0.93, 1.09; I² 68.1%) and allergic rhinitis (OR 0.99 95%CI 0.87, 1.12; I² 72.9%) being significantly heterogeneous.

CONCLUSIONS

Inconsistencies between the studies were too large to accurately assess the association between residential greenness and allergic respiratory disease. A standardised global measure of greenness which accounts for seasonal variation at a specific relevant buffer size is needed to create a more cohesive body of evidence and for future examination of the effect of residential greenness on allergic respiratory diseases.

Physician and parent barriers to the use of oral corticosteroids for the prevention of paediatric URTI-induced acute asthma exacerbations at home

Objectives

Administration of oral corticosteroids at the onset of an upper respiratory tract infection (URTI) can be effective in the management of acute asthma exacerbations in children. This study was designed to identify barriers to parent-initiated implementation of clinical practice guideline-recommended use of oral corticosteroids for prophylaxis against severe asthma exacerbations in children.

Methods

Twenty-seven children who presented to BC Children's Hospital with URTI-induced asthma exacerbations were recruited. Parents received a filled prescription for a course of oral corticosteroids to be used at the earliest onset of their child's next URTI. Each family was contacted monthly over a 1-year period to inquire about URTI events, asthma symptoms, medication use and health care utilization. Focus groups were held with family physicians, paediatricians and parents; transcripts were analyzed qualitatively to identify key themes.

Results

Incidence of URTI events among participants was high (85%). Uptake of study medication was low; 44% used the medication as directed at their first URTI event. Eleven per cent of the patients who used the study medication also visited the emergency department for an exacerbation. Focus groups identified four main barriers to the effective use of parent-initiated oral corticosteroids: physician resistance and conflicting messages from providers; parent uncertainty about oral corticosteroids; multiple caregivers and relative ease of access to an emergency department.

Conclusion

We have identified key barriers to the effective use of parent-administered oral corticosteroids as an asthma management strategy and gained important insights regarding the research that is required to enhance the applicability of the strategy.

Asthma in British Columbia: Are we finally breathing easier? A population-based study of the burden of disease over 14 years

OBJECTIVE

Asthma presents a significant global burden, but whether the incidence and prevalence of asthma is rising is still debated. The objective of this study was to determine the prevalence and incidence of asthma in British Columbia (BC), Canada, and characterize associated health services utilization.

METHODS

We extracted data from provincial administrative hospitalization, medical services, and prescription drug databases for patients aged 5 to 55 years, during 1996 to 2009 having ≥270 MSP registration days and meeting asthma definition of: ≥1 hospital admissions with asthma as the principal diagnosis, or ≥2 physician visits for asthma as the principal diagnosis, or ≥3 asthma drug dispensings. Regression models were used to test change in asthma incidence and prevalence, and use of various health care services, such as physician and emergency department (ED) visits, and hospitalizations.

RESULTS

379,950 patients met the study criteria. The prevalence (2.6%) and incidence (0.7%) of asthma was relatively stable over the study period. There was a decline in proportion of patients visiting family practitioners (FP) (OR 0.92; 95% CI 0.90-0.94), specialists (OR 0.60; 95% CI 0.58-0.62), using ED services (OR 0.31; 95% CI 0.30-0.32) and hospitalizations (OR 0.34; 95% CI 0.31-0.37). Regional differences were noted, with lower rates of FP and specialist visits and higher rates of ED visits for asthma in rural versus urban areas.

CONCLUSIONS

In BC, the incidence and prevalence of asthma has remained stable over 14 years. Although health service utilization declined, there is variation between rural and urban regions.

Decline in admissions for childhood asthma, a 26-year period population-based study

BACKGROUND

The prevalence of childhood asthma has increased, although the rate of hospitalization for asthma seems to decrease. In Norway, the rate of hospital admission for childhood asthma from 1984 to 2000 increased. The aim of this study was to assess further trends in hospital admissions for childhood asthma up to 2010.

METHODS

A population-based study including children 1-13 yrs of age hospitalized for asthma during six periods from 1984/1985 to 2009/2010 in Rogaland, Norway, was performed. Medical records from 1536 admissions (1050 children) were studied; and gender, age, number of admissions, length of hospital stay, medications and symptoms were recorded.

RESULTS

For all age groups, the rate of admissions per 10.000 increased from 20.1 in 1984/85 to 33.7 in 1989/90, but declined to 14.4 in 2009/2010. Rates were highest in boys (OR 1.87; 95% CI: 1.69, 2.09), younger age groups (OR 2.51; 2.38, 2.64) and decreased from 1984 to 2010 (OR 0.92; 0.88, 0.94). The rates of readmissions were higher than for primary admissions (OR 1.33; 1.19, 1.47). From 1984 to 2010, there was an increased use of inhaled corticosteroids prior to admission (6 to 51%) and started at discharge (7 to 37%), and systemic steroids given during admission (19 to 83%).

CONCLUSION

There has been a substantial decline in the rate of hospital admissions for childhood asthma after 1989/1990, with major differences between age groups and genders. The decline could be due to improved care of children with asthma or a real reduction in asthma exacerbations.

Stable admission rate for acute asthma in Danish children since 1977

Childhood asthma is consistently reported to have increased in recent decades in most westernized countries, but it is unknown if this increase is similar across severities. We aimed to study the time-trend of acute hospital admission and readmission for asthma of school-aged children in the recent 35 years in Denmark. We analyzed time-trends in the national incidence rate of hospitalization for acute severe asthma in children aged 5-15 in Denmark during the 35-year period 1977-2012 in the Danish national registry. Only in-patient admissions with a principal diagnosis of asthma (ICD-8: 493** or ICD-10: J45** or J46**) were included. Among children with asthma hospitalizations, we investigated the risk of readmission beyond 1 month of first admission. Admissions were summarized as rates per thousand person years at risk. The overall time-trend is stable with a rate of one admission per year per thousand children at risk and a per-year incidence rate ratio 0.999 [95 % CI 0.997-1.001]. The rate of any readmission decreased from approximately 20 per thousand children in the eighties to less than 10 in the early nineties before stabilizing at around 10 per thousand children from mid-nineties and onwards. During 35 years of nation-wide follow-up, we find a highly stable incidence rate of first hospital admission for acute severe asthma in children. Moreover, rates of readmission halved during the seventies and stabilized in the last twenty years. In conclusion, our data suggest that the reported increase in childhood asthma is mainly due to less severe cases.

Time trends in the incidence, prevalence and age at diagnosis of asthma in children

BACKGROUND

Current knowledge on the prevalence of asthma is mainly based on cross-sectional questionnaire data. Current population-based data on the incidence of asthma in children are scarce.

OBJECTIVE

To study the incidence, prevalence, and age at diagnosis of asthma in children in the Netherlands over the study period 2000-2012.

METHODS

A population-based cohort study was conducted in the Integrated Primary Care Information database. The cohort consisted of 176,516 children (379,536 personyears (PY) of follow-up), aged 5-18 years between 2000 and 2012. All medical records of children with physician diagnosed asthma were validated. Incidence rates, annual percent change (APC), and prevalence for asthma were calculated. Influence of age and gender on incidence rates and change in age at diagnosis were studied.

RESULTS

We identified an asthma cohort of 14,303 children with 35,118 PY. The overall incidence rate was 6.7/1000 PY (95% CI, 6.45-6.97). Until 2008, the incidence rate was significantly increasing (APC 5.79 (95% CI 1.43-10.34); from 2008 onwards, a non-significant decrease was observed (APC -12.16 (95% CI -23.07 to 0.28). Incidence for girls was lower than for boys, this difference decreased with increasing age. (p < 0.001) Overall, the age at diagnosis increased over calendar time and was lower for boys. (linear trend p < 0.001).

CONCLUSION

Our population-based cohort study observed an incidence rate of 6.7 per 1000 PY of physician-diagnosed asthma in children in the Netherlands over 2000-2012. The asthma incidence rate was increasing until 2008. Further studies are needed to confirm the decrease in asthma incidence rate from 2008 onwards.

Trends in the age of diagnosis of childhood asthma

BACKGROUND

The cause of rising asthma incidence over time remains unexplained. Examining trends in the age of diagnosis across successive birth cohorts may offer insights into asthma etiology.

OBJECTIVE

To examine trends in the age at asthma diagnosis and the age and proportion of children hospitalized at first asthma diagnosis in Ontario, Canada.

METHODS

Eight consecutive birth cohorts of children (1993-2000) were observed using administrative data from a universal health insurance plan in Ontario, Canada (population 13 million). Trends in the need for hospitalization and age at asthma diagnosis were examined with descriptive and survival analyses.

RESULTS

The records of 1,059,511 children were examined, of whom 201,958 developed asthma in the first 8 years of life, with an average cumulative incidence of 19.1%. Mean age at asthma diagnosis decreased from 4.7 ± 1.5 years in birth year 1993 to 2.6 ± 2.0 years in birth year 2000 (P < .0001), with a higher adjusted risk of asthma diagnosis (hazard ratio, 6.7; 95% CI, 6.5-6.9) in the first 3 years of life for children born after 1996 versus children born in the period 1993 to 1995 (hazard ratio, 1.4; 95% CI, 1.3-1.4). The proportion of children hospitalized at asthma diagnosis stayed stable while the age at first asthma hospitalization decreased over time (P < .0001).

CONCLUSIONS

This study demonstrates a significant increase in asthma incidence and a decrease in the age of asthma diagnosis across multiple birth cohorts. Changes in asthma incidence over time are primarily explained by variations in asthma rates in children younger than 3 years.

[Admissions for pediatric asthma in France]

INTRODUCTION

Most hospital admissions for asthma exacerbation are avoidable with adequate disease management. The objective of this study was to describe admissions for asthma in children in France using data from the French nationwide hospital database.

METHODS

We selected admissions having either a main diagnosis of asthma or a main diagnosis of acute respiratory failure (ARF) with asthma as an associated diagnosis, occurring in children (age<15years) between 2002 and 2010 in France (excluding French Guyana).

RESULTS

In 2010, 35,004 asthma admissions and 1381 cases of asthma-related ARF were recorded (crude admission rate, 30.1/10,000 children); the mean length of stay was 2days. The in-hospital lethality rate ranged from 0.01% to 0.03% depending on the year. The annual age-standardized admission rate increased between 2002 and 2010 (+2.5% per year on average in metropolitan France). In 2010, 11.8% of children admitted for asthma or asthma-related ARF were readmitted for asthma or asthma-related ARF at least once within the same calendar year, and 1.3% were readmitted within the week following admission. The proportion of children aged less than 5 years who were readmitted within the same calendar year increased between 2002 and 2010.

CONCLUSION

The increase in admission and readmission rates indicates non-optimal management of asthma in children in France.

Medication use in Australian children with asthma: user's perspective

BACKGROUND AND OBJECTIVES

Medication use-related issues remain problematic in childhood asthma despite effective treatment strategies and public investment into improved asthma management strategies in industrialized countries. This study aimed to carry out an in-depth exploration of the views of parents/carers and children with asthma on medication use.

METHODS

Semi-structured qualitative interviews were conducted with a purposive convenience sample of children with asthma and their parents recruited from general practices in Sydney. Interviews were tape-recorded, transcribed verbatim, and thematically analyzed.

RESULTS

A total of 52 interviews (26 parents/carers and 26 children with asthma) were conducted. Major themes which emerged from the children's interviews included issues such as self-image, resistance to medication use, and lack of responsibility in medication taking. Parental or carer issues included lack of clear understanding of how medications worked, as well as administration difficulties, cost constraints, and beliefs about medications contrary to quality use.

DISCUSSION

This is one of the few research studies exploring the viewpoint of children with asthma about their medications in Australia. Despite investment in dissemination of professional, targeted evidence-based asthma management strategies in healthcare, there seems to be a lack of depth in terms of what parents understand about their child's asthma. Effective communication about medication usage, especially the inclusion of the child in the consultation to empower them to be involved in their own asthma care, may be the answer.