Wheeze and asthma prevalence and related health-service use in white and south Asian pre-schoolchildren in the United Kingdom

Ethnic variation in asthma healthcare utilisation and exacerbation: systematic review and meta-analysis

Background

Patients from ethnic minority groups (EMGs) frequently report poorer asthma outcomes; however, a broad synthesis summarising ethnic disparities is yet to be undertaken. What is the magnitude of ethnic disparities in asthma healthcare utilisation, exacerbations and mortality?

Methods

MEDLINE, Embase and Web of Science databases were searched for studies reporting ethnic variation in asthma healthcare outcomes (primary care attendance, exacerbation, emergency department (ED) visits, hospitalisation, hospital readmission, ventilation/intubation and mortality) between White patients and those from EMGs. Estimates were displayed using forest plots and random-effects models were used to calculate pooled estimates. We conducted subgroup analyses to explore heterogeneity, including by specific ethnicity (Black, Hispanic, Asian and other).

Results

65 studies, comprising 699 882 patients, were included. Most studies (92.3%) were conducted in the United States of America (USA). Patients from EMGs had evidence suggestive of lower levels of primary care attendance (OR 0.72, 95% CI 0.48-1.09), but substantially higher ED visits (OR 1.74, 95% CI 1.53-1.98), hospitalisations (OR 1.63, 95% CI 1.48-1.79) and ventilation/intubation (OR 2.67, 95% CI 1.65-4.31) when compared to White patients. In addition, we found evidence suggestive of increased hospital readmissions (OR 1.19, 95% CI 0.90-1.57) and exacerbation rates (OR 1.10, 95% CI 0.94-1.28) among EMGs. No eligible studies explored disparities in mortality. ED visits were much higher among Black and Hispanic patients, while Asian and other ethnicities had similar rates to White patients.

Conclusions

EMGs had higher secondary care utilisation and exacerbations. Despite the global importance of this issue, the majority of studies were performed in the USA. Further research into the causes of these disparities, including whether these vary by specific ethnicity, is required to aid the design of effective interventions.

Sensitivity of FEV1 and Clinical Parameters in Children With a Suspected Asthma Diagnosis

BACKGROUND

Asthma is the most common chronic disease in children and a robust diagnosis is crucial to optimize patient care and reduce its burden. To diagnose asthma in children, the Global Initiative for Asthma (GINA) recommendations propose a 12% improvement in forced expiratory volume in 1 second (FEV₁) after a bronchodilation test. Nevertheless, such a criterion is rarely confirmed in these patients in clinical practice.

OBJECTIVE

The objective of this study was to evaluate the sensitivity of spirometric and clinical parameters in identifying children with possible asthma.

METHODS

The VERI-VEMS Study is a multicenter international retrospective cohort study. Data were collected, from January 2008 until January 2019, for all consecutive children (aged 5-18 years), with a diagnosis of asthma, who performed a spirometry at the time of the diagnosis. We compared the sensitivity of the reversibility criterion proposed by GINA guidelines, with other spirometric and clinical variables, using physician-diagnosed asthma and response to treatment as the standard.

RESULTS

The study included 871 children. The reversibility criterion of 12% of FEV₁ showed a sensitivity of 30.4%. The 3 best spirometric or clinical criteria were the presence of dry cough, or wheezing or atopy and dry cough, or wheezing or exercise-induced dyspnea, with a sensitivity reaching 99.5%, with no added value of the spirometric parameters in the calculation of the cumulated sensitivity for the diagnosis of pediatric asthma.

CONCLUSIONS

Postbronchodilator reversibility of 12%, although essential for patients' follow-up, has an insufficient low sensitivity in reaching a diagnosis of asthma in pediatric patients, compared with a combination of clinical symptoms, that show a better sensitivity. Further studies on specificity will help clarify the role of this change in the diagnostic paradigm in formally diagnosing children with asthma.

ITGB4 Deficiency in Airway Epithelium Aggravates RSV Infection and Increases HDM Sensitivity

Background

The heterogeneity of RSV-infected pathology phenotype in early life is strongly associate with increased susceptibility of asthma in later life. However, the inner mechanism of this heterogeneity is still obscure. ITGB4 is a down-regulated adhesion molecular in the airway epithelia of asthma patients which may participate in the regulation of RSV infection related intracellular pathways.

Object

This study was designed to observe the involvement of ITGB4 in the process of RSV infection and the effect of ITGB4 deficiency on anti-RSV responses of airway epithelia.

Results

RSV infection caused a transient decrease of ITGB4 expression both in vitro and in vivo. Besides, ITGB4 deficiency induced not only exacerbated RSV infection, but also enhanced HDM sensitivity in later life. Moreover, IFN III (IFN-λ) was significantly suppressed during RSV infection in ITGB4 deficient airway epithelial cells. Furthermore, the suppression of IFN-λ were regulated by IRF-1 through the phosphorylation of EGFR in airway epithelial cells after RSV infection.

Conclusion

These results demonstrated the involvement of ITGB4 deficiency in the development of enhance RSV infection in early life and the increased HDM sensitivity in later life by down-regulation of IFN-λ through EGFR/IRF-1 pathway in airway epithelial cells.

Burden of allergic disease among ethnic minority groups in high-income countries

The COVID‐19 pandemic raised acute awareness regarding inequities and inequalities and poor clinical outcomes amongst ethnic minority groups. Studies carried out in North America, the UK and Australia have shown a relatively high burden of asthma and allergies amongst ethnic minority groups. The precise reasons underpinning the high disease burden are not well understood, but it is likely that this involves complex gene–environment interaction, behavioural and cultural elements. Poor clinical outcomes have been related to multiple factors including access to health care, engagement with healthcare professionals and concordance with advice which are affected by deprivation, literacy, cultural norms and health beliefs. It is unclear at present if allergic conditions are intrinsically more severe amongst patients from ethnic minority groups. Most evidence shaping our understanding of disease pathogenesis and clinical management is biased towards data generated from white population resident in high‐income countries. In conjunction with standards of care, it is prudent that a multi‐pronged approach towards provision of composite, culturally tailored, supportive interventions targeting demographic variables at the individual level is needed, but this requires further research and validation. In this narrative review, we provide an overview of epidemiology, sensitization patterns, poor clinical outcomes and possible factors underpinning these observations and highlight priority areas for research.

Key considerations when involving children in health intervention design: reflections on working in partnership with South Asian children in the UK on a tailored Management and Intervention for Asthma (MIA) study

Participatory research is an empowering process through which individuals can increase control over their lives, and allows researchers/clinicians to gain a clearer understanding of a child's needs. However, involving children in participatory research is still relatively novel, despite national and international mandates to engage children in decision making. This paper draws on the learnings from designing the Management and Intervention for Asthma (MIA) study, which used a collaborative participatory method to develop an intervention-planning framework for South Asian children with asthma. There are currently 1 million children in the UK receiving treatment for asthma, making it one of the most prevalent chronic childhood illnesses. Symptoms of asthma are often underrecognized in children from South Asian communities in the UK, contributing to increased disease severity and increased attendance at the emergency department compared to White British children. Despite this, ethnic minorities are often excluded from research and thus absent from the 'evidence base', making it essential to hear their perspectives if health inequalities are to be successfully addressed. We worked alongside healthcare professionals, community facilitators, parents, and children to identify the key concerns and priorities they had and then designed the framework around their needs. Reflecting on the process, we identified several key considerations that need to be addressed when co-developing interventions with children. These include the power dynamics between the parent/researcher and child; navigating the consent/assent process; how parental involvement might affect the research; establishing a convenient time and location; how to keep children engaged throughout the process; tailoring activities to different levels of ability; and accounting for cultural differences. These factors were considered by the researchers when designing the study, however, implementing them was not without its challenges and highlighted the need for researchers to develop expertise in this field. Tailoring existing research methods allowed us to explore children's perceptions, priorities, and experiences of illness more effectively. However, involving children in participatory research is a complex undertaking, and researchers need to ensure that they have the expertise, time, and resources necessary to be able to fully support the needs of child participants before deciding to commit to this approach.

A structured collaborative approach to intervention design using a modified intervention mapping approach: a case study using the Management and Interventions for Asthma (MIA) project for South Asian children

BACKGROUND

To describe how using a combined approach of community-based participatory research and intervention mapping principles could inform the development of a tailored complex intervention to improve management of asthma for South Asian (SA) children; Management and Interventions for Asthma (MIA) study.

METHODS

A qualitative study using interviews, focus groups, workshops, and modified intervention mapping procedures to develop an intervention planning framework in an urban community setting in Leicester, UK. The modified form of intervention mapping (IM) included: systematic evidence synthesis; community study; families and healthcare professionals study; and development of potential collaborative intervention strategies. Participants in the community study were 63 SA community members and 12 key informants; in-depth semi-structured interviews involved 30 SA families, 14 White British (WB) families and 37 Healthcare Professionals (HCPs) treating SA children living with asthma; prioritisation workshops involved 145 SA, 6 WB and 37 HCP participants; 30 participants in finalisation workshops.

RESULTS

Two key principles were utilised throughout the development of the intervention; community-based participatory research (CBPR) principles and intervention mapping (IM) procedures. The CBPR approach allowed close engagement with stakeholders and generated valuable knowledge to inform intervention development. It accounted for diverse perceptions and experiences with regard to asthma and recognised the priorities of patients and their families/caregivers for service improvement. The 'ACT on Asthma' programme was devised, comprising four arms of an intervention strategy: education and training, clinical support, advice centre and raising awareness, to be co-ordinated by a central team.

CONCLUSIONS

The modified IM principles utilised in this study were systematic and informed by theory. The combined IM and participatory approach could be considered when tailoring interventions for other clinical problems within diverse communities. The IM approach to intervention development was however resource intensive. Working in meaningful collaboration with minority communities requires specific resources and a culturally competent methodology.

Isolated night cough in children: how does it differ from wheeze?

It has been postulated that some children with recurrent cough but no wheeze have a mild form of asthma (cough variant asthma), with similar risk factors and an increased risk of future wheeze.

This longitudinal study compared risk factors for isolated night cough and for wheeze in the Leicester Respiratory Cohort in children aged 1, 4, 6 and 9 years and compared prognosis of children with isolated night cough, children with wheeze and asymptomatic children.

We included 4101 children aged 1 year, 2854 aged 4 years, 2369 aged 6 years and 1688 aged 9 years. The prevalence of isolated night cough was 10% at age 1 year and 18% in older children. Prevalence of wheeze decreased from 35% at 1 year to 13% at 9 years. Although several risk factors were similar for cough and wheeze, day care, reflux and family history of bronchitis were more strongly associated with cough, and male sex and family history of asthma with wheeze. Over one-third of preschool children with cough continued to cough at school age, but their risk of developing wheeze was similar to that of children who were asymptomatic at earlier surveys. Wheeze tracked more strongly throughout childhood than cough.

In conclusion, our study showed that only some risk factors for cough and wheeze were shared but many were not, and there was little evidence for an increased risk of future wheeze in children with isolated night cough. This provides little support for the hypothesis that recurrent cough without wheeze may indicate a variant form of asthma.

Children with isolated night cough do not have an increased risk of future wheeze, and risk factors for cough and wheeze only partially overlap.https://bit.ly/31IbXSC

The risk of preschool asthma at 2-4 years is not associated with leukocyte telomere length at birth or at 1 year of age

Background

Exposure to prenatal stress is associated with offspring allergic-disease development, and oxidative stress may mediate this relationship.

Objective

We aimed to evaluate whether leukocyte telomere length (LTL) shortening, a marker for exposure to oxidative stress, in early life is associated with increased risk of asthma development during the preschool period.

Methods

We assessed the follow-up clinical data of a subgroup from a birth cohort whose LTLs had been measured from cord-blood and 1-year peripheral-blood samples. We examined whether the LTLs would be associated with asthma development at the age of 2–4 years.

Results

The data of 84 subjects were analyzed. LTLs were measured from the cord-blood and 1-year peripheral blood of 75 and 79 subjects, respectively. Among them, 14 subjects (16.7%) developed bronchial asthma between 2–4 years old. Prenatally stressed subjects had marginally increased odds of developing asthma (p = 0.097). There was no significant difference in the odds of preschool-asthma development between the groups with shorter and longer cord-blood LTLs (odds ratio [OR], 0.651; 95% confidence interval [CI], 0.184–2.306) or in the odds between the groups with shorter and longer 1-year peripheral-blood LTLs (OR, 0.448; 95% CI, 0.135–1.483). Finally, subjects with both higher prenatal stress and shorter LTLs did not have significantly higher odds of preschool-asthma development (for cord-blood: OR, 1.242; 95% CI, 0.353–4.368; for 1-year peripheral-blood: OR, 1.451; 95% CI, 0.428–4.919).

Conclusion

There was no significant association between early life LTLs and higher risk of bronchial-asthma development during the preschool years.

Behavioral interventions for asthma self-management in South Asian populations: a systematic review

OBJECTIVE

Asthma outcomes are significantly worse for minority groups, including South Asians (SAs), in high-income settings. Despite this, comparatively few existing studies have focused on SAs when studying the effectiveness of behavioral interventions on asthma self-management, and no prior study has synthesized these findings. We review the effectiveness of behavioral interventions on asthma management in adults and children of SA origin across low- (LICs), middle- (MICs), and high-income countries (HICs).

METHODS

Data sources included EMBASE, MEDLINE, Cochrane Library and Trial registries: WHO, ICTRP and ClinicalTrials.gov. Eligibility criteria: randomized controlled trials (RCTs), quasi-RCTs and non-RCTs (controlled before-after [CBA] studies), published in English, with no publication year or country restrictions in adults and children of South Asian origin. Exclusion criteria: those focusing solely on pharmacological interventions. Search terms were "asthma" and "South Asian".

RESULTS

We included 33 studies, 27 from MICs and 6 from HICs (education [n = 10], self-management plans [n = 6], yoga/breathing exercises [n = 10]) organizational interventions [n =1], diet therapy [n = 1] and combined interventions [n = 5]). Outcome measures included: blood biochemistry, lung function, healthcare utilization and quality of life. A meta-analysis was not performed due to significant study heterogeneity.

CONCLUSION

Behavioral interventions for asthma management in SAs are effective. Educational interventions that aim to optimize asthma knowledge, control, and inhaler technique, and yoga/breathing exercises are most effective for improved long-term outcomes in adults and children across LICs and MICs. Further research is needed to evaluate the effectiveness of all behavioral interventions for SAs in HICs to better inform current guidance by policy makers and health care providers.

Assessing the association between bronchiolitis in infancy and recurrent wheeze: a whole English birth cohort case-control study

The precise association between bronchiolitis and predisposition to childhood wheeze is unclear. We assessed bronchiolitis aetiology and later wheeze phenotypes in the entire 2007 English birth cohort. All infants admitted to hospital in England during their first year of life with bronchiolitis or urinary tract infection (UTI) were followed using Hospital Episode Statistics to determine risk and characteristics of wheeze admission over the subsequent 8 years. In our cohort of 21 272 children compared with UTI, the risk of wheeze admission was higher with previous bronchiolitis (risk ratio (RR) 2.4), even higher in those with non-respiratory syncytial virus bronchiolitis (RR 3.1) and persisted into late-onset wheeze (RR 1.7).

Patient reported outcomes for preschool children with recurrent wheeze

Children with preschool wheeze regularly attend UK emergency departments. There is no international consensus on any specific personalised management approach. This paper describes the first attempt to co-design patient-centred outcomes with families. Preschool wheezers' parents participated in semi-structured interviews and focus-group discussions to air their concerns and identify potential additional support. Fifty-seven families participated in these interviews. From these, themes were defined through qualitative content analysis. Parental experience was mapped to the patient pathway and seven important personalised outcomes were described. These can be used to inform a tool which following further validation could potentially support management of children with preschool wheeze and provide an additional patient focused clinical outcome measure in audit and research.

Prevalence of recurrent wheezing during the first year of life in Setúbal district, Portugal

BACKGROUND

Recurrent wheezing during the first year of life is a major cause of respiratory morbidity worldwide, yet there are no studies on its prevalence in Portugal.

OBJECTIVE

Determine the prevalence and severity of recurrent wheezing, treatments employed and other related aspects, in infants during their first year of life in Setúbal, Portugal.

METHODS

This is a cross-sectional study of a random sample of infants aged 12-15 months living in Setúbal district. It uses a validated questionnaire answered by parents/caregivers at local healthcare facilities where infants attend for growth/development monitoring and/or vaccine administration.

RESULTS

Among the 202 infants surveyed, 44.6% (95% CI 37.7-51.4) had at least one episode of wheezing; and 18.3% (95% CI 12.9-23.6) had recurrent wheezing. There was significant morbidity associated to recurrent wheezing in terms of severe episodes (17.3%-95% CI 12-22.5), visits to the emergency department (26.2%-95% CI 20.1-32.2) and hospital admissions (5.4%-95% CI 2.2-8.5); 10.4% (95% CI 6.1-14.6) used inhaled corticosteroids and 7.9% (95% CI 4.1-11.6) used a leukotriene receptor antagonist.

CONCLUSIONS

The prevalence of recurrent wheezing in infants during the first year of life is high and is associated with significant morbidity, presenting as a relevant public health problem. An important proportion of infants' progress with a more severe condition, resulting in high use of health resources (visits to emergency department and hospitalisations). The prevalence of recurrent wheezing in this district of Portugal stays between those related in other European and Latin American Centres, suggesting that maybe some of the well-known risk factors are shared with affluent countries.

Qualitative study to identify ethnicity-specific perceptions of and barriers to asthma management in South Asian and White British children with asthma

OBJECTIVE

This paper draws on the data from the Management and Interventions for Asthma (MIA) study to explore the perceptions and experiences of asthma in British South Asian children using semi-structured interviews. A comparable cohort of White British children was recruited to identify whether any emerging themes were subject to variation between the two groups so that generic and ethnicity-specific themes could be identified for future tailored intervention programmes for South Asian children with asthma.

SETTING

South Asian and White British children with asthma took part in semi-structured interviews in Leicester, UK.

PARTICIPANTS

Thirty three South Asian and 14 White British children with asthma and aged 5-12 years were interviewed.

RESULTS

Both similar and contrasting themes emerged from the semi-structured interviews. Interviews revealed considerable similarities in the experience of asthma between the South Asian and White British children, including the lack of understanding of asthma (often confusing trigger with cause), lack of holistic discussions with healthcare professionals (HCPs), an overall neutral or positive experience of interactions with HCPs, the role of the family in children's self-management and the positive role of school and friends. Issues pertinent to South Asian children related to a higher likelihood of feeling embarrassed and attributing physical activity to being a trigger for asthma symptoms.

CONCLUSIONS

The two ethnicity-specific factors revealed by the interviews are significant in children's self-management of asthma and therefore, indicate the need for a tailored intervention in South Asian children.

Management of Recurrent Preschool, Doctor-Diagnosed Wheeze

Preschool wheeze occurs in half of the children before they reach 6 y of age and recurrence is also common. Recurrent preschool wheeze is classified as either typical or atypical. For typical recurrent preschool wheeze, the diagnoses are either asthma or bronchiolitis/bronchitis. Responsiveness to a properly administered bronchodilator confirms asthma, atopic or otherwise. All atypical preschool wheeze should be referred to pediatric respirologist for assessment. Lung function test by impulse oscillometry (IOS) before and after bronchodilator is helpful to confirm airway hyperresponsiveness, an essential feature of asthma. Assessment of atopy is important by either skin prick test or serum IgE level. Treatment of acute wheeze includes standard supportive care, bronchodilator for those diagnosed with asthma and hypertonic saline for those diagnosed as having acute bronchiolitis. Other treatments included nebulized adrenaline for acute bronchiolitis and systemic steroids for asthma. For those with significant respiratory distress, continuous positive airway pressure (CPAP) or heated humidified high flow should be considered. Daily or intermittent inhaled corticosteroid or intermittent montelukast would reduce asthma exacerbation rate. A significant proportion of preschool wheeze persists till school age. An early diagnosis of asthma would be important to allow early optimal management.

Changes in the prevalence and severity of recurrent wheezing in infants: The results of two surveys administered 7 years apart

OBJECTIVE

To identify changes in the prevalence and severity of recurrent wheezing (RW) in infants using data obtained from two surveys administered seven years apart.

METHODS

A cross-sectional, international, population-based study in infants aged 12-15 months was conducted. Data were obtained from two surveys (S1 and S2, in 2005 and 2012, respectively) using the same methodology in three large Latin American cities: Curitiba (Brazil), São Paulo (Brazil), and Santiago (Chile).

RESULTS

A decrease in the overall prevalence of RW was identified between S1 (23.3%) and S2 (20.4%), p = 0.004, but it was mainly driven by the reduction observed in São Paulo; in Curitiba and Santiago, this change was not significant. The mean prevalence of the following RW severity indicators remained high and stable: severe wheezing episodes (56.9% in S1 and 54.2% in S2, p = 0.32) and emergency department (ED) visits for wheezing (S1 = 68.1%, S2 70.9%, p = 0.21). A significant increase in admissions for wheezing (21.1% to 26.7%, p = 0.004) was observed. In Curitiba and São Paulo, there were significant increases in the prevalence of physician-diagnosed asthma and in the use of inhaled corticosteroids and oral antileukotrienes.

CONCLUSIONS

The prevalence and severity of RW during the first year of life remained high over time, with remarkably high rates of ED visits, admissions for wheezing and use of asthma medications. This study suggests the need for considering early asthma diagnosis and to establish an appropriate treatment in infants with recurrent and severe asthma-like symptoms.

A qualitative study to identify parents' perceptions of and barriers to asthma management in children from South Asian and White British families

Background

Over one million children receive treatment for asthma in the UK. South Asian children experience excess morbidity and higher rates of hospitalization than the White population. This study aimed to explore perceptions and experiences of asthma and asthma management in British South Asian and White British families, to identify barriers to optimal management and to inform culturally appropriate interventions to improve management.

Methods

A qualitative methodology, using semi-structured interviews was adopted. Members of 30 families from six major South Asian ethnic-religious groups were purposively sampled (n = 49). For comparison, 17 White British parents were interviewed. Topics included understandings of asthma; day-to-day management; interactions with health care providers and the perceived quality of healthcare services. Data were analyzed using interpretive thematic analysis, facilitated by NVivo. Similarities and differences between South Asian and White families were analysed across key themes.

Results

Many of the problems facing families of a child with asthma were common to South Asian and White British families. Both had limited understanding of asthma causes and triggers and expressed confusion about the use of medications. Both groups reported delays in receiving a clear diagnosis and many experienced what was perceived as uncoordinated care and inconsistent advice from health professionals. No family had received an asthma plan. South Asian families had more difficulty in recognising severity of symptoms and those with limited English faced additional barriers to receiving adequate information and advice about management due to poor communication support systems. South Asian parents reported higher levels of involvement of wider family and higher levels of stigma. Attendance at the emergency department was related to previous experience, difficulties in accessing primary care, lack of knowledge of alternatives and difficulties in assessing severity.

Conclusions

Barriers to optimal asthma management exist at the individual family, community and healthcare systems levels. Culturally sensitive, holistic and collaboratively designed interventions are needed. Improved communication support for families with lower proficiency in English is required. Healthcare professionals need to ensure that families receive an asthma plan and make greater efforts to check families’ understandings of asthma triggers, use of medications, assessment of asthma severity and accessing help.

Breastfeeding, maternal asthma and wheezing in the first year of life: a longitudinal birth cohort study

The impact of breastfeeding on respiratory health is uncertain, particularly when the mother has asthma. We examined the association of breastfeeding and wheezing in the first year of life.We studied 2773 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort. Caregivers reported on infant feeding and wheezing episodes at 3, 6 and 12 months. Breastfeeding was classified as exclusive, partial (supplemented with formula or complementary foods) or none.Overall, 21% of mothers had asthma, 46% breastfed for at least 12 months and 21% of infants experienced wheezing. Among mothers with asthma, breastfeeding was inversely associated with infant wheezing, independent of maternal smoking, education and other risk factors (adjusted rate ratio (aRR) 0.52; 95% CI 0.35-0.77 for ≥12 versus <6 months breastfeeding). Compared with no breastfeeding at 6 months, wheezing was reduced by 62% with exclusive breastfeeding (aRR 0.38; 95% CI 0.20-0.71) and by 37% with partial breastfeeding supplemented with complementary foods (aRR 0.63; 95% CI 0.43-0.93); however, breastfeeding was not significantly protective when supplemented with formula (aRR 0.89; 95% CI 0.61-1.30). Associations were not significant in the absence of maternal asthma (p-value for interaction <0.01).Breastfeeding appears to confer protection against wheezing in a dose-dependent manner among infants born to mothers with asthma.

Infantile wheeze: rethinking dogma

Wheeze is a common symptom in young children and is usually associated with viral illnesses. It is a major source of morbidity and is responsible for a high consumption of healthcare and economic resources worldwide. A few children have a condition resembling classical asthma. Rarer specific conditions may have a wheezy component and should be considered in the differential diagnosis. Over the last half century, there have been many circular discussions about the best way of managing preschool wheeze. In general, intermittent wheezing should be treated with intermittent bronchodilator therapy, and a controller therapy should be prescribed for a young child with recurrent wheezing only if positively indicated, and only then if carefully monitored for efficacy. Good multidisciplinary support, attention to environmental exposition and education are essential in managing this common condition. This article analyses the pathophysiological basis of wheezing in infancy and critically discusses the evolution of the scientific progress over time in this unique field of respiratory medicine.

Asthma management in British South Asian children: an application of the candidacy framework to a qualitative understanding of barriers to effective and accessible asthma care

Background

In the UK, people of South Asian origin with asthma experience excess morbidity, with hospitalisation rates three times those of the majority White population and evidence suggests that South Asian children with asthma are more likely to suffer uncontrolled symptoms and hospital admissions with acute asthma compared to White British children. This paper draws on data from The Management and Interventions for Asthma (MIA) study to identify the operation of barriers to optimal care and good asthma control for South Asian children.

Methods

The MIA study followed a multi-phase, iterative, participatory design, underpinned by the socio-ecological model. Findings presented here are from face-to face, semi-structured interviews with South Asian (Indian, Pakistani and Bangladeshi origin) parents and carers of a child with asthma (n = 49). Interviews were conducted in English or relevant South Asian languages using specially trained community facilitators. Data were transcribed verbatim and analysed according to the principles of interpretive thematic analysis, facilitated by the use of NVivo.

Results

Seven dimensions of candidacy are identified: identification of candidacy; navigation; the permeability of asthma services; appearances at health services; adjudications; offers and resistance and operating conditions in the local production of candidacy. The analysis demonstrates several ways in which a potential lack of alignment between the priorities and competencies of British South Asian families and the organization of health services combine to create vulnerabilities and difficulties in effectively managing childhood asthma.

Conclusions

Healthcare systems have a responsibility to develop services that are sensitive and appropriate to the needs of their communities. In South Asian communities, further efforts are required to raise awareness of symptoms and effectively communicate how, when and where to seek help for children. There is a need for improved diagnosis and consistent, effectively communicated information, especially regarding medication. Parents made several suggestions for improving services: presentations about asthma at easily accessible community venues; an advice centre or telephone helpline to answer queries; opportunities for sharing experiences with other families; having information provided in South Asian languages; longer GP appointments; extended use of asthma nurses; and better education for healthcare professionals to ensure consistency of care and advice.

Incidence and characteristics of early childhood wheezing, Dhaka, Bangladesh, 2004-2010

BACKGROUND

Early childhood wheezing substantially impacts quality of life in high-income countries, but data are sparse on early childhood wheezing in low-income countries. We estimate wheezing incidence, describe wheezing phenotypes, and explore the contribution of respiratory viral illnesses among children aged <5 years in urban Bangladesh.

METHODS

During 2004-2010, respiratory illness surveillance was conducted through weekly home visits. Children with fever or respiratory illness were referred for examination by study physicians including lung auscultation. During 2005-2007, every fifth referred child had nasal washes tested for human metapneumovirus, respiratory syncytial viruses, and influenza and parainfluenza viruses.

RESULTS

During April 2004-July 2010, 23,609 children were enrolled in surveillance. Of these, 11,912 (50%) were male, median age at enrollment was 20 months (IQR 5-38), and 4,711 (20%) had ≥1 wheezing episode accounting for 8,901 episodes (733 [8%] associated with hospitalization); 25% wheezed at <1 year of age. Among children aged <5 years, incidences of wheezing and wheezing hospitalizations were 2,335/10,000 and 192/10,000 child-years. Twenty-eight percent had recurrent wheezing. Recurrent versus non-recurrent wheezing episodes were more likely to be associated with oxygen saturation <93% (OR 6.9, 95%CI 2.8-17.3), increased work of breathing (OR 1.6, 95%CI 1.4-1.8), and hospitalization (OR 2.0, 95%CI 1.6-2.4). Respiratory viruses were detected in 66% (578/873) of episodes with testing.

CONCLUSION

In urban Bangladesh, early childhood wheezing is common and largely associated with respiratory virus infections. Recurrent wheezing is associated with more severe illness and may predict children who would benefit most from closer follow-up and targeted interventions. Pediatr Pulmonol. 2016;51:588-595. © 2015 Wiley Periodicals, Inc.

Prevalence, Severity, and Treatment of Recurrent Wheezing During the First Year of Life: A Cross-Sectional Study of 12,405 Latin American Infants

PURPOSE

This study aimed to determine the prevalence and severity of recurrent wheezing (RW) defined as ≥3 episodes of wheezing, risk factors, and treatments prescribed during the first year of life in Latin American infants.

METHODS

In this international, cross-sectional, and community-based study, parents of 12,405 infants from 11 centers in 6 South American countries (Argentina, Brazil, Chile, Colombia, Peru, and Uruguay) completed a questionnaire about wheezing and associated risk/protective factors, asthma medications, and the frequency of and indications for the prescription of antibiotics and paracetamol during the first year of life.

RESULTS

The prevalence of RW was 16.6% (95% CI 16.0-17.3); of the 12,405 infants, 72.7% (95% CI 70.7-74.6) visited the Emergency Department for wheezing, and 29.7% (27.7-31.7) was admitted. Regarding treatment, 49.1% of RW infants received inhaled corticosteroids, 55.7% oral corticosteroids, 26.3% antileukotrienes, 22.9% antibiotics ≥4 times mainly for common colds, wheezing, and pharyngitis, and 57.5% paracetamol ≥4 times. Tobacco smoking during pregnancy, household income per month <1,000 USD, history of parental asthma, male gender, and nursery school attendance were significant risk factors for higher prevalence and severity of RW, whereas breast-feeding for at least 3 months was a significant protective factor. Pneumonia and admissions for pneumonia were significantly higher in infants with RW as compared to the whole sample (3.5-fold and 3.7-fold, respectively).

CONCLUSIONS

RW affects 1.6 out of 10 infants during the first year of life, with a high prevalence of severe episodes, frequent visits to the Emergency Department, and frequent admissions for wheezing. Besides the elevated prescription of asthma medications, there is an excessive use of antibiotics and paracetamol in infants with RW and also in the whole sample, which is mainly related to common colds.

"Attacks" or "Whistling": Impact of Questionnaire Wording on Wheeze Prevalence Estimates

Background

Estimates of prevalence of wheeze depend on questionnaires. However, wording of questions may vary between studies. We investigated effects of alternative wording on estimates of prevalence and severity of wheeze, and associations with risk factors.

Methods

White and South Asian children from a population-based cohort (UK) were randomly assigned to two groups and followed up at one, four and six years (1998, 2001, 2003). Parents were asked either if their child ever had “attacks of wheeze” (attack group, N=535), or “wheezing or whistling in the chest” (whistling group, N=2859). All other study aspects were identical, including questions about other respiratory symptoms.

Results

Prevalence of wheeze ever was lower in the attack group than in the whistling group for all surveys (32 vs. 40% in white children aged one year, p<0.001). Prevalence of other respiratory symptoms did not differ between groups. Wheeze tended to be more severe in the attack group. The strength of association with risk factors was comparable in the two groups.

Conclusions

The wording of questions on wheeze can affect estimates of prevalence, but has less impact on measured associations with risk factors. Question wording is a potential source of between-study-heterogeneity in meta-analyses.

The burden of asthma among the South Asian and Chinese population residing in Ontario

BACKGROUND

The South Asian and Chinese populations represent a significant portion of the population of Ontario; however, little is known about the burden of respiratory OBJECTIVE: To investigate the prevalence of asthma and the associated health care burden among South Asian and Chinese populations living in Ontario.

METHODS

Using administrative health data for Ontario, the authors identified individuals of South Asian and Chinese descent using a validated surname algorithm and compared the prevalence of asthma in these groups with the general population using an established asthma case definition for the period 2002 to 2010. Also compared were the rates of asthma-specific emergency department visits and hospitalizations among the ethnic groups.

RESULTS

In 2010, the prevalence of asthma in South Asians residing in Ontario was similar to that of the general population (12.1% versus 12.4%), and was increasing at a faster rate than in the general population (0.51%⁄year versus 0.34%⁄year). Compared with the general population, the South Asian population had fewer emergency department visits for asthma, whereas the asthma-related hospitalization rate was greatest among the South Asian population (0.45 per 100 person-years). The Chinese population had the lowest asthma prevalence and associated health care use.

CONCLUSION

The burden of asthma among South Asians in Ontario is increasing and warrants further investigation to determine the reasons for this rise.

The use of a collaborative structured methodology for the development of a multifaceted intervention programme for the management of asthma (the MIA project), tailored to the needs of children and families of South Asian origin: a community-based, participatory study

Background

Asthma is one of the most common chronic childhood illnesses in the UK. South Asian children are more likely to suffer from their asthma and be admitted to hospital. While this inequality needs to be addressed, standard behaviour-change interventions are known to be less successful in minority ethnic groups. Evidence suggests a need to enhance services provided to ethnic minority communities by developing culturally sensitive tailored interventions.

Objectives

The Management and Interventions for Asthma (MIA) project aimed to test an iterative multiphase participatory approach to intervention development underpinned by the socioecological model of health, producing an intervention-planning framework and enhancing an evidence-based understanding of asthma management in South Asian and White British children.

Design

Interviews and focus groups facilitated by community facilitators (CFs) were used to explore knowledge and perceptions of asthma among South Asian communities, children, families and healthcare professionals (HCPs). A smaller comparison group of White British families was recruited to identify aspects of asthma management that could be addressed either by generic interventions or by a tailored approach. Collaborative workshops were held to develop an intervention planning framework and to prioritise an aspect of asthma management that would be used as an exemplar for the development of the tailored, multifaceted asthma intervention programme.

Setting

The community study was based in a largely urban environment in Leicester, UK.

Participants

Participants were recruited directly from the South Asian (Indian, Pakistani and Bangladeshi) and White British communities, and through the NHS. Children were aged between 4 and 12 years, with a range of asthma severity.

Intervention development

The study had four phases. Phase 1 consisted of an evidence review of barriers and facilitators to asthma management in South Asian children. Phase 2 explored lay understandings of childhood asthma and its management among South Asian community members (n = 63). Phase 3 explored perceptions and experiences of asthma management among South Asian (n = 82) and White British families (n = 31) and HCP perspectives (n = 37). Using a modified intervention mapping approach incorporating psychological theory, phase 4 developed an intervention planning framework addressing the whole asthma pathway leading to the development of an exemplar multifaceted, integrated intervention programme called ‘ACT [Awareness, Context (cultural and organisational) and Training] on Asthma’.

Results

Data on the social patterning of perceptions of asthma and a lack of alignment between the organisation of health services, and the priorities and competencies of British South Asian communities and families were produced. Eleven key problem areas along the asthma pathway were identified. A four-arm multifaceted tailored programme, ‘ACT on Asthma’, was developed, focusing on the theme ‘getting a diagnosis’. This theme was chosen following prioritisation by families during the collaborative workshops, demonstrating the participatory, iterative, phased approach used for the intervention design.

Conclusions

The MIA study demonstrated barriers to optimal asthma management in children at the family, provider and healthcare system levels and across the whole asthma pathway. Interventions need to address each of these levels to be effective. Minority ethnic communities can be successfully engaged in collaborative intervention development with a community-focused and culturally sensitive methodology.

Future work

Further research is required to (1) assess the feasibility and effectiveness of the proposed ‘ACT on Asthma’ programme, (2) develop methods to increase active participation of children in research and service development, (3) develop and test strategies to enhance public understanding of asthma in South Asian communities and (4) identify effective means of engaging the wider family in optimising asthma management.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

A systematic review of explanatory factors of barriers and facilitators to improving asthma management in South Asian children

BACKGROUND

South Asian children with asthma are less likely to receive prescriptions and more likely to suffer uncontrolled symptoms and acute asthma admissions compared with White British children. Understanding barriers are therefore vital in addressing health inequalities. We undertook a systematic review identifying explanatory factors for barriers and facilitators to asthma management in South Asian children. South Asians were defined as individuals of Indian, Pakistani or Bangladeshi descent.

METHODS

Data Sources - Medline, HMIC, EMBASE, ASSIA, Web of Science, BNI, CINAHL, PsycINFO, OpenSIGLE, CRD, Scopus, NHS Evidence, Cochrane Library, Campbell Collaboration, RCPCH, ATS, ERS, Asthma UK, Google Scholar & Asthma Guidelines (BTS, GINA, ATS, Monash, NAEPP, Singapore & New Zealand) to August 2013.Inclusion Criteria - Qualitative, quantitative or mixed methods research with primary focus on identifying explanations for barriers and/or facilitators to asthma management in South Asian children aged 0-18 years with diagnosed/suspected asthma and/or carers and/or healthcare professionals.Data Extraction - Three authors independently reviewed, selected & extracted eligible articles with disagreements resolved by research team discussion.

RESULTS

15 studies encompassing 25,755 children, 18,483 parents/carers and 239 healthcare professionals were included. Barriers and explanatory factors identified were:1. Lack of asthma knowledge in families and healthcare professionals.2. Under-use of preventer medications.3. Non-acceptance/denial of asthma.4. Over-reliance on Emergency Department management.5. Communication problems.6. Non-adherence to medication.7. Use of complementary therapies.Little facilitators regarding asthma management were identified.

CONCLUSIONS

Several key issues were identified as likely to be ethnic-specific to South Asian families, rather than a reflection of minority status: impact of parental and professional knowledge and beliefs, health service utilisation pattern explanations and the impact of prejudice and stigmatisation. Other explanations such as language barriers are not strictly ethnic specific but instead reflect a minority position.Further research is required to identify why barriers exist, the mechanisms by which they impact on asthma management and how they can be overcome. Furthermore, understanding the difference between barriers and explanations that are ethnic-specific and those that are related to being a minority will enable the application of generic system-wide interventions where ethnicity is not the issue and ethnically-tailored interventions where needed.

Tobacco intervention teachable moments for pediatric otolaryngologists: atopy and second hand smoke exposure among children

OBJECTIVES

Pediatric otolaryngology clinics have tremendous access to children with allergic conditions, yet no research has evaluated in this setting environmental tobacco smoke and the occurrence of atopic diseases.

METHODS

Caregivers or parents of 201 consecutive patients in a Hungarian pediatric otolaryngology clinic were queried on otolaryngologic conditions; self-reported diagnoses of atopic diseases; and tobacco smoke exposure.

RESULTS

A history of asthma was reported in 10.3% of children; 38.7% had at least one parent who smoked. Fifteen out of the 20 children with asthma (75.0%) had at least one parent who smoked. Having a diagnosis of hay fever and having a parent who smoked greatly increased the odds of having a diagnosis of asthma.

CONCLUSIONS

Second hand smoke exposure among children in an otolaryngology clinic was common, and was associated with co-existing atopic conditions. Pediatric otolaryngologists have an important opportunity to address parental smoking as part their care of children.

Socioeconomic and sociodemographic factors associated with asthma related outcomes in early childhood: the Generation R Study

Rationale

Few studies have analyzed the association of socioeconomic and sociodemographic factors with asthma related outcomes in early childhood, including Fraction of exhaled Nitric Oxide (FeNO) and airway resistance (Rint). We examined the association of socioeconomic and sociodemographic factors with wheezing, asthma, FeNO and Rint at age 6 years. Additionally, the role of potential mediating factors was studied.

Methods

The study included 6717 children participating in The Generation R Study, a prospective population-based cohort study. Data on socioeconomic and sociodemographic factors, wheezing and asthma were obtained by questionnaires. FeNO and Rint were measured at the research center. Statistical analyses were performed using logistic and linear regression models.

Results

At age 6 years, 9% (456/5084) of the children had wheezing symptoms and 7% (328/4953) had asthma. Children from parents with financial difficulties had an increased risk of wheezing (adjusted Odds Ratio (aOR) = 1.63, 95% Confidence Interval (CI):1.18–2.24). Parental low education, paternal unemployment and child's male sex were associated with asthma, independent of other socioeconomic or sociodemographic factors (aOR = 1.63, 95% CI:1.24–2.15, aOR = 1.85, 95% CI:1.11–3.09, aOR = 1.58, 95% CI:1.24–2.01, respectively). No socioeconomic or gender differences in FeNO were found. The risks of wheezing, asthma, FeNO and Rint measurements differed between ethnic groups (p<0.05). Associations between paternal unemployment, child's sex, ethnicity and asthma related outcomes remained largely unexplained.

Conclusions

This study showed differences between the socioeconomic and sociodemographic correlates of wheezing and asthma compared to the correlates of FeNO and Rint at age 6 years. Several socioeconomic and sociodemographic factors were independently associated with wheezing and asthma. Child's ethnicity was the only factor independently associated with FeNO. We encourage further studies on underlying pathways and public health intervention programs, focusing on reducing socioeconomic or sociodemographic inequalities in asthma.

Etiology of ethnic differences in childhood spirometry

OBJECTIVES

Age- and height-adjusted spirometric lung function of South Asian children is lower than those of white children. It is unclear whether this is purely genetic, or partly explained by the environment. In this study, we assessed whether cultural factors, socioeconomic status, intrauterine growth, environmental exposures, or a family and personal history of wheeze contribute to explaining the ethnic differences in spirometric lung function.

METHODS

We studied children aged 9 to 14 years from a population-based cohort, including 1088 white children and 275 UK-born South Asians. Log-transformed spirometric data were analyzed using multiple linear regressions, adjusting for anthropometric factors. Five different additional models adjusted for (1) cultural factors, (2) indicators of socioeconomic status, (3) perinatal data reflecting intrauterine growth, (4) environmental exposures, and (5) personal and family history of wheeze.

RESULTS

Height- and gender-adjusted forced vital capacity (FVC) and forced expired volume in 1 second (FEV1) were lower in South Asian than white children (relative difference -11% and -9% respectively, P < .001), but PEF and FEF50 were similar (P ≥ .5). FEV1/FVC was higher in South Asians (1.8%, P < .001). These differences remained largely unchanged in all 5 alternative models.

CONCLUSIONS

Our study confirmed important differences in lung volumes between South Asian and white children. These were not attenuated after adjustment for cultural and socioeconomic factors and intrauterine growth, neither were they explained by differences in environmental exposures nor a personal or family history of wheeze. This suggests that differences in lung function may be mainly genetic in origin. The implication is that ethnicity-specific predicted values remain important specifically for South Asian children.

Early respiratory morbidity in a multicultural birth cohort: the Generation R Study

Ethnic disparities in the prevalence of asthma symptoms in children have been described. We evaluated to what extent the association between ethnic background and respiratory symptoms during the first 2 years of life could be explained by the mediating effect of risk factors for respiratory morbidity. The Generation R Study is a multiethnic, population-based birth cohort study. Pre and postnatal risk factors for respiratory morbidity were prospectively assessed by questionnaires. Information about ethnicity was available for 5,684 infants. The associations between ethnic background and lower respiratory symptoms at 12 and 24 months were evaluated with log-binomial regression models. Relative risks and 95 % confidence intervals (RR [95 % CI]) were computed for Cape Verdean, Moroccan, Antillean, Surinamese and Turkish ethnicity with Dutch ethnicity as the reference category. We found an increased risk of lower respiratory symptoms at 24 months in Antillean infants (1.32 [95 % CI 1.12-1.57]) that was mediated by early postnatal exposures (pets keeping, siblings, breastfeeding, daycare attendance, smoke exposure). Turkish infants also had an increased risk of lower respiratory symptoms at 12 and 24 months (1.14 [95 % CI 1.02-1.27] and 1.21 [95 % CI 1.07-1.38], respectively), partly explained by previous morbidity (eczema, infections and upper respiratory symptoms). There were no differences for Cape Verdean, Moroccan or Surinamese, as compared to Dutch infants. Hence, ethnic background was associated with respiratory symptoms during the first 2 years of life and this association was largely explained by mediating effects of known pre and postnatal risk factors for respiratory morbidity.

Environmental injustices of children's exposure to air pollution from road-transport within the model British multicultural city of Leicester: 2000-09

The significant contribution of road-transport to air pollution within the urban arena is widely acknowledged, and traditionally explored in relation to health outcomes across a temporal scale. However, the structure of the urban environment is also of importance in dictating the existence of extremely variable traffic pollutant levels, which often tend to be linked with social disparities. Nevertheless 'Environmental Justice' studies have rarely tackled the adverse health implications of exposures from mobile sources (Chakraborty, 2009), or have applied statistical techniques that are appropriate for such spatial data (Gilbert and Chakraborty, 2011). This article addresses these gaps by spatially examining the distribution of respiratory hospitalisation incidents of children aged 0-15 years in relation to social circumstances and residential exposures of annual PM(10) road-transport emissions within Leicester during 2000-09. Continuing upon the theme of 'Environmental Justice', the research explores the intra-urban spatial distribution of those who produce and residentially experience the majority of road-transport emissions. The findings indicate significant global relationships to exist between children's hospitalisation rates and social-economic-status, ethnic minorities, and PM(10) road-transport emissions within Leicester. Local Indicators of Spatial Association (LISA) and Geographically Weighted Regression (GWR) identified important localised variations within the dataset, specifically relating to a double-burden of residentially experienced road-transport emissions and deprivation effecting inner city children's respiratory health. Furthermore, affluent intra-urban communities tended to contribute the highest levels of emission from private transport, while residentially experiencing relatively low exposure of transport emissions. This would suggest that environmental injustices prevail across the model British multicultural city of Leicester.

Risk factors for current wheezing and its phenotypes among elementary school children

BACKGROUND

Accumulating evidence suggests, asthma includes many phenotypes with varying clinical and prognostic features. Epidemiological surveys documented a number of environmental risk factors for the development of asthma and interestingly these differ between and within countries, suggesting that the differences may be related with the different distribution of asthma phenotypes. This study aimed to investigate risk factors of current wheezing (CW) and different wheezing phenotypes in elementary school children.

METHODS

Six thousand nine hundred sixty-three 9- to 11-year-old children of a previous multicenter survey where the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase-II was used were analyzed. Wheezing phenotypes were defined as wheezing with rhinitis (RW), wheezing with rhinoconjunctivitis (RCW), atopic wheezing (AW), non-atopic wheezing (NAW), and frequent wheezing (FW) (≥4/year wheezing episodes).

RESULTS

The prevalence of CW was 15.8% and among these, 22.4%, 67.3%, 45.9%, 20.5%, and 79.5% were classified as FW, RW, RCW, AW, and NAW, respectively. History of parental asthma/allergic rhinitis, coexistence of other allergic diseases, presence of mold and dampness in the house lived during the first year of life and maternal smoking in pregnancy were found to be risk factors for most phenotypes (odds ratio (OR) ranged from 1.43 to 3.56). Number of household in the last year (OR = 1.14), prematurity (OR = 2.08), and duration of breastfeeding (OR = 1.02) per additional month were found to be risk factor for FW, AW, and RCW, respectively.

CONCLUSION

Beside common risk factors for the development of asthma and its phenotypes, certain risk factors appeared to play a role in the development of phenotypic characteristics of asthma. These findings support our hypothesis that each phenotype has not only different clinical characteristics but also has different roots.

Global strategy for the diagnosis and management of asthma in children 5 years and younger

Asthma is the most common chronic disease of childhood and the leading cause of childhood morbidity from chronic disease as measured by school absences, emergency department visits, and hospitalisation. During the past two decades, many scientific advances have improved our understanding of asthma and our ability to manage and control it effectively. However, in children 5 years and younger, the clinical symptoms of asthma are variable and non-specific. Furthermore, neither airflow limitation nor airway inflammation, the main pathologic hallmarks of the condition, can be assessed routinely in this age group. For this reason, to aid in the diagnosis of asthma in young children, a symptoms-only descriptive approach that includes the definition of various wheezing phenotypes has been recommended. In 1993, the Global Initiative for Asthma (GINA) was implemented to develop a network of individuals, organizations, and public health officials to disseminate information about the care of patients with asthma while at the same time assuring a mechanism to incorporate the results of scientific investigations into asthma care. Since then, GINA has developed and regularly revised a Global Strategy for Asthma Management and Prevention. Publications based on the Global Strategy for Asthma Management and Prevention have been translated into many different languages to promote international collaboration and dissemination of information. In this report, Global Strategy for Asthma Management and Prevention in Children 5 Years and Younger, an effort has been made to present the special challenges that must be taken into account in managing asthma in children during the first 5 years of life, including difficulties with diagnosis, the efficacy and safety of drugs and drug delivery systems, and the lack of data on new therapies. Approaches to these issues will vary among populations in the world based on socioeconomic conditions, genetic diversity, cultural beliefs, and differences in healthcare access and delivery. Patients in this age group are often managed by pediatricians and general practitioners routinely faced with a wide variety of issues related to childhood diseases.

International study of wheezing in infants: risk factors in affluent and non-affluent countries during the first year of life

Risk factors for wheezing during the first year of life (a major cause of respiratory morbidity worldwide) are poorly known in non-affluent countries. We studied and compared risk factors in infants living in affluent and non-affluent areas of the world. A population-based study was carried out in random samples of infants from centres in Latin America (LA) and Europe (EU). Parents answered validated questionnaires referring to the first year of their infant's life during routine health visits. Wheezing was stratified into occasional (1-2 episodes, OW) and recurrent (3 + episodes, RW). Among the 28687 infants included, the most important independent risk factors for OW and RW (both in LA and in EU) were having a cold during the first 3 months of life [OR for RW 3.12 (2.60-3.78) and 3.15 (2.51-3.97); population attributable fraction (PAF) 25.0% and 23.7%]; and attending nursery school [OR for RW 2.50 (2.04-3.08) and 3.09 (2.04-4.67); PAF 7.4% and 20.3%]. Other risk factors were as follows: male gender, smoking during pregnancy, family history of asthma/rhinitis, and infant eczema. Breast feeding for >3 months protected from RW [OR 0.8 (0.71-0.89) in LA and 0.77 (0.63-0.93) in EU]. University studies of mother protected only in LA [OR for OW 0.85 (0.76-0.95) and for RW 0.80 (0.70-0.90)]. Although most risk factors for wheezing are common in LA and EU; their public health impact may be quite different. Avoiding nursery schools and smoking in pregnancy, breastfeeding babies >3 months, and improving mother's education would have a substantial impact in lowering its prevalence worldwide.

Phenotypes of childhood asthma: are they real?

It has been suggested that there are several distinct phenotypes of childhood asthma or childhood wheezing. Here, we review the research relating to these phenotypes, with a focus on the methods used to define and validate them. Childhood wheezing disorders manifest themselves in a range of observable (phenotypic) features such as lung function, bronchial responsiveness, atopy and a highly variable time course (prognosis). The underlying causes are not sufficiently understood to define disease entities based on aetiology. Nevertheless, there is a need for a classification that would (i) facilitate research into aetiology and pathophysiology, (ii) allow targeted treatment and preventive measures and (iii) improve the prediction of long-term outcome. Classical attempts to define phenotypes have been one-dimensional, relying on few or single features such as triggers (exclusive viral wheeze vs. multiple trigger wheeze) or time course (early transient wheeze, persistent and late onset wheeze). These definitions are simple but essentially subjective. Recently, a multi-dimensional approach has been adopted. This approach is based on a wide range of features and relies on multivariate methods such as cluster or latent class analysis. Phenotypes identified in this manner are more complex but arguably more objective. Although phenotypes have an undisputed standing in current research on childhood asthma and wheezing, there is confusion about the meaning of the term 'phenotype' causing much circular debate. If phenotypes are meant to represent 'real' underlying disease entities rather than superficial features, there is a need for validation and harmonization of definitions. The multi-dimensional approach allows validation by replication across different populations and may contribute to a more reliable classification of childhood wheezing disorders and to improved precision of research relying on phenotype recognition, particularly in genetics. Ultimately, the underlying pathophysiology and aetiology will need to be understood to properly characterize the diseases causing recurrent wheeze in children.

Properdin in childhood and its association with wheezing and atopy

Properdin, a serum glycoprotein, is an important component of innate immunity, the only known positive regulator of complement, acting as an initiation point for alternative pathway activation. As an X-linked protein, we hypothesized that properdin may play a modulatory role in the pathogenesis of viral wheeze in children, which tends to be more common and more severe in boys. We aimed to determine properdin levels in a community-based paediatric sample, and to assess whether levels of properdin were associated with childhood wheeze phenotypes and atopy. We studied 137 school-children aged 8-12 yrs, a nested sample from a cohort study. Properdin was measured by a commercial enzyme-linked immunoabsorbant assay. We assessed wheeze by questionnaire, validated it by a nurse-led interview and performed skin prick tests and a methacholine challenge in all children. Forty children (29%) reported current wheeze. Serum properdin levels ranged between 18 and 40 microg/ml. Properdin was not associated with age, gender, atopy, bronchial responsiveness, current wheeze (neither the viral wheeze nor multiple-trigger wheeze phenotype) or severity of wheeze, but was slightly lower in south Asian (median 21.8 microg/ml) compared with white children (23.3 microg/ml; p = 0.006). Our data make it unlikely that properdin deficiency is common in healthy children or that levels of properdin are a major risk factor for wheeze or atopy.

The transient value of classifying preschool wheeze into episodic viral wheeze and multiple trigger wheeze

BACKGROUND

A recently proposed method for classifying preschool wheeze is to describe it as either episodic (viral) wheeze or multiple trigger wheeze. In research studies, phenotype is generally determined by retrospective questionnaire.

AIM

To determine whether recently proposed phenotypes of preschool wheeze are stable over time.

METHODS

In all, 132 two to six-year-old children with doctor diagnosed asthma on maintenance inhaled corticosteroids were classified as having episodic (viral) wheeze or multiple trigger wheeze at a screening visit and then followed up at three-monthly intervals for a year. At each follow-up visit, standardized questionnaires were used to determine whether the subjects wheezed only with, or also in the absence of colds. Stability of the phenotypes was assessed at the end of the study.

RESULTS

Phenotype as determined by retrospective parental report at the start of the study was not predictive of phenotype during the study year. Phenotypic classification remained the same in 45.9% of children and altered in 54.1% of children.

CONCLUSION

When children with preschool wheeze are classified into episodic (viral) wheeze or multiple trigger wheeze based on retrospective questionnaire, the classification is likely to change significantly within a 1-year period.

Regular vs prn nebulized treatment in wheeze preschool children

BACKGROUND

International guidelines recommend regular treatment with inhaled glucocorticoids for children with frequent wheezing; however, prn inhaled bronchodilator alone or in combination with glucocorticoid is also often used in practice. We aimed to evaluate whether regular nebulized glucocorticoid plus a prn bronchodilator or a prn nebulized bronchodilator/glucocorticoid combination is more effective than prn bronchodilator alone in preschool children with frequent wheeze.

METHODS

Double-blind, double-dummy, randomized, parallel-group trial. After a 2-week run-in period, 276 symptomatic children with frequent wheeze, aged 1-4 years, were randomly assigned to three groups for a 3-month nebulized treatment: (1) 400 microg beclomethasone bid plus 2500 microg salbutamol prn; (2) placebo bid plus 800 microg beclomethasone/1600 microg salbutamol combination prn; (3) placebo bid plus 2500 microg salbutamol prn. The percentage of symptom-free days was the primary outcome measure. Secondary outcomes included symptom scores, use of relief medication and exacerbation frequency.

RESULTS

As compared with prn salbutamol (61.0 +/- 24.83 [SD]), the percentage of symptom-free days was higher with regular beclomethasone (69.6%, SD 20.89; P = 0.034) but not with prn combination (64.9%, SD 24.74). Results were no different in children with or without risk factors for developing persistent asthma. The effect of prn combination was no different from that of regular beclomethasone on the primary and on several important secondary outcomes.

CONCLUSIONS

Regular inhaled glucocorticoid is the most effective treatment for frequent wheezing in preschool children. However, prn bronchodilator/glucocorticoid combination might be an alternative option, but it requires further study.