Understanding the seasonal pattern of childhood asthma: results from the National Cooperative Inner-City Asthma Study (NCICAS)

The Bitemporal Lens Model-toward a holistic approach to chronic disease prevention with digital biomarkers

Objectives

We introduce the Bitemporal Lens Model, a comprehensive methodology for chronic disease prevention using digital biomarkers.

Materials and Methods

The Bitemporal Lens Model integrates the change-point model, focusing on critical disease-specific parameters, and the recurrent-pattern model, emphasizing lifestyle and behavioral patterns, for early risk identification.

Results

By incorporating both the change-point and recurrent-pattern models, the Bitemporal Lens Model offers a comprehensive approach to preventive healthcare, enabling a more nuanced understanding of individual health trajectories, demonstrated through its application in cardiovascular disease prevention.

Discussion

We explore the benefits of the Bitemporal Lens Model, highlighting its capacity for personalized risk assessment through the integration of two distinct lenses. We also acknowledge challenges associated with handling intricate data across dual temporal dimensions, maintaining data integrity, and addressing ethical concerns pertaining to privacy and data protection.

Conclusion

The Bitemporal Lens Model presents a novel approach to enhancing preventive healthcare effectiveness.

Asthma as a Risk Factor for Hospitalization in Children and Youth With COVID-19: A Retrospective Cohort Study

BACKGROUND

Studies examining the association between asthma and hospitalization among children and youth with coronavirus disease 2019 (COVID-19) have yielded mixed results. Both asthma and COVID-19 hospitalization are characterized by racial, ethnic and socioeconomic disparities which also pattern geographically, yet no studies to date have adjusted for neighborhood context in the assessment of this association.

METHODS

Mixed effects logistic regression was used to estimate the association between asthma and hospitalization due to COVID-19 in a sample of 28,997 children and youth diagnosed with COVID-19 in Milwaukee County, Wisconsin, from March 1, 2020, to May 31, 2022. Models adjusted for individual-level sociodemographic factors (age, gender, race, ethnicity and city/suburb residence) and season of diagnosis were examined as moderators. Random intercepts by census tract accounted for geographic variation in neighborhood factors and census tract-level measures of education, health and environment, and social and economic factors were assessed via childhood opportunity indices.

RESULTS

Asthma history was statistically significantly associated with hospitalization due to COVID-19 among children and youth. Hospitalization rates varied statistically significantly by census tract, and results were unchanged after accounting for childhood opportunity indices and census tract. Season of diagnosis was not found to moderate the effect of asthma history on COVID-19 hospitalization.

CONCLUSION

Our study suggests that asthma history is a risk factor for hospitalization in the context of COVID-19 infection among children and youth, warranting observation and follow-up of children with asthma as well as continued measures to prevent COVID-19 in this population.

Breathing zone pollutant levels are associated with asthma exacerbations in high-risk children

Background

Indoor and outdoor air pollution levels are associated with poor asthma outcomes in children. However, few studies have evaluated whether breathing zone pollutant levels associate with asthma outcomes.

Objective

Determine breathing zone exposure levels of NO 2 , O 3 , total PM 10 and PM 10 constituents among children with exacerbation-prone asthma, and examine correspondence with in-home and community measurements and associations with outcomes.

Methods

We assessed children's personal breathing zone exposures using wearable monitors. Personal exposures were compared to in-home and community measurements and tested for association with lung function, asthma control, and asthma exacerbations.

Results

81 children completed 219 monitoring sessions. Correlations between personal and community levels of PM 10 , NO 2 , and O 3 were poor, whereas personal PM 10 and NO 2 levels correlated with in-home measurements. However, in-home monitoring underdetected brown carbon (Personal:79%, Home:36.8%) and ETS (Personal:83.7%, Home:4.1%) personal exposures, and detected black carbon in participants without these personal exposures (Personal: 26.5%, Home: 96%). Personal exposures were not associated with lung function or asthma control. Children experiencing an asthma exacerbation within 60 days of personal exposure monitoring had 1.98, 2.21 and 2.04 times higher brown carbon (p<0.001), ETS (p=0.007), and endotoxin (p=0.012), respectively. These outcomes were not associated with community or in-home exposure levels.

Conclusions

Monitoring pollutant levels in the breathing zone is essential to understand how exposures influence asthma outcomes, as agreement between personal and in-home monitors is limited. Inhaled exposure to PM 10 constituents modifies asthma exacerbation risk, suggesting efforts to limit these exposures among high-risk children may decrease their asthma burden.

CLINICAL IMPLICATIONS

In-home and community monitoring of environmental pollutants may underestimate personal exposures. Levels of inhaled exposure to PM 10 constituents appear to strongly influence asthma exacerbation risk. Therefore, efforts should be made to mitigate these exposures.

CAPSULE SUMMARY

Leveraging wearable, breathing-zone monitors, we show exposures to inhaled pollutants are poorly proxied by in-home and community monitors, among children with exacerbation-prone asthma. Inhaled exposure to multiple PM 10 constituents is associated with asthma exacerbation risk.

Targeting immunodominant Bet v 1 epitopes with monoclonal antibodies prevents the birch allergic response

BACKGROUND

Blocking the major cat allergen, Fel d 1, with mAbs was effective in preventing an acute cat allergic response.

OBJECTIVES

This study sought to extend the allergen-specific antibody approach and demonstrate that a combination of mAbs targeting Bet v 1, the immunodominant and most abundant allergenic protein in birch pollen, can prevent the birch allergic response.

METHODS

Bet v 1-specific mAbs, REGN5713, REGN5714, and REGN5715, were isolated using the VelocImmune platform. Surface plasmon resonance, x-ray crystallography, and cryo-electron microscopy determined binding kinetics and structural data. Inhibition of IgE-binding, basophil activation, and mast cell degranulation were assessed via blocking ELISA, flow cytometry, and the passive cutaneous anaphylaxis mouse model.

RESULTS

REGN5713, REGN5714, and REGN5715 bind with high affinity and noncompetitively to Bet v 1. A cocktail of all 3 antibodies, REGN5713/14/15, blocks IgE binding to Bet v 1 and inhibits Bet v 1- and birch pollen extract-induced basophil activation ex vivo and mast cell degranulation in vivo. Crystal structures of the complex of Bet v 1 with immunoglobulin antigen-binding fragments of REGN5713 or REGN5715 show distinct interaction sites on Bet v 1. Cryo-electron microscopy reveals a planar and roughly symmetrical complex formed by REGN5713/14/15 bound to Bet v 1.

CONCLUSIONS

These data confirm the immunodominance of Bet v 1 in birch allergy and demonstrate blockade of the birch allergic response with REGN5713/14/15. Structural analyses show simultaneous binding of REGN5713, REGN5714, and REGN5715 with substantial areas of Bet v 1 exposed, suggesting that targeting specific epitopes is sufficient to block the allergic response.

Seasonal Variation in miR-328-3p and let-7d-3p Are Associated With Seasonal Allergies and Asthma Symptoms in Children

OBJECTIVE

MicroRNAs (miRs) are small non-coding RNA molecules of around 18-22 nucleotides that are key regulators of many biologic processes, particularly inflammation. The purpose of this study was to determine the association of circulating miRs from asthmatic children with seasonal variation in allergic inflammation and asthma symptoms.

METHODS

We used available small RNA sequencing on blood serum from 398 children with mild-to-moderate asthma from the Childhood Asthma Management Program. We used seasonal asthma symptom data at the study baseline and allergen affection status from baseline skin prick tests as primary outcomes. We identified differentially expressed (DE) miRs between pairs of seasons using DESeq2. Regression analysis was used to identify associations between allergy status to specific seasonal allergens and DE miRs in 4 seasons and between seasonal asthma symptom data and DE miRs. We performed pathway enrichment analysis for target genes of the DE miRs using DAVID.

RESULTS

After quality control, 398 samples underwent differential analysis between the 4 seasons. We found 52 unique miRs from a total of 81 DE miRs across seasons. Further investigation of the association between these miRs and sensitization to seasonal allergens using skin prick tests revealed that 26 unique miRs from a total of 38 miRs were significantly associated with a same-season allergen. Comparison between seasonal asthma symptom data revealed that 2 of these 26 miRs also had significant associations with asthma symptoms in the same seasons: miR-328-3p (P < 0.03) and let-7d-3p (P < 0.05). Enrichment analysis showed that the most enriched pathway clusters were Rap1, Ras, and MAPK signaling pathways.

CONCLUSION

Our results show seasonal variation in miR-328-3p and let-7d-3p are significantly associated with seasonal asthma symptoms and seasonal allergies. These indicate a potentially protective role for let-7d-3p and a deleterious role for miR-328-3p in asthmatics sensitized to mulberry. Further work will determine whether these miRs are drivers or results of the allergic response.

Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort

Background

The interplay between COVID‐19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID‐19 pandemic on childhood asthma outcomes.

Methods

The PeARL multinational cohort included 1,054 children with asthma and 505 non‐asthmatic children aged between 4 and 18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID‐19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control.

Results

During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks, and hospitalizations due to asthma, in comparison with the preceding year. Sixty‐six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre‐bronchodilatation FEV₁ and peak expiratory flow rate were improved during the pandemic. When compared to non‐asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits, or hospitalizations during the pandemic. However, an increased risk of URTIs emerged.

Conclusion

Childhood asthma outcomes, including control, were improved during the first wave of the COVID‐19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID‐19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent.

Epidemiology and utilization of primary health care services in Qatar by asthmatic children 5-12 years old: secondary data analysis 2016-2017

Background

Childhood asthma is a growing clinical problem and a burden on the health care system due to repetitive visits to children's emergency departments and frequent hospital admissions where it is poorly controlled. Due to lack of reliable baseline information on its prevalence among children in Qatar and the extent of their utilization of primary health care services, we sought to analyse electronic medical records data for children aged 5-12 years.

Objectives

Our primary objective was to establish point prevalence over the period 2016-2017. Furthermore, we wanted to assess the frequency and pattern of use of the primary care services including any demographic and seasonal variations, the types of clinical encounter and treatment received.

Methods

A cross sectional study on 54,704 clinical encounters of electronic health records for children aged 5 to 12 years in which a diagnosis of Asthma was tagged during a two years period.

Results

The prevalence rate of Asthma out of total registered clients in the specified pediatric age group (196,557) is 6.1%. The rate was highest (10.2%) in youngest age group (5-6 years old) and lowest (4.1%) in teenagers (10-12 years old). An obvious peak of clinical encounters of Asthma cases was observed in Oct and Nov. The work load in PHCC clinics for Asthma clinical encounters is increased by more than 50% compared to the average monthly count of 4556.Moreover, the rate was higher in males (7.6%) compared to females (4.6%). The most frequently prescribed medication group was antihistamine (57.8%) followed by adrenergic bronchodilators (33.9%).

Conclusions

Asthma constitutes an important part (8.5%) of the total primary care clinic work load among children aged 5-12 years in Qatar. A guideline need to encourage physician to use preventive Asthma strategies including steroid medications to provide continuity of care for Asthma cases.

Inner-City Asthma in Children

Asthma in inner-city children is often severe and difficult to control. Residence in poor and urban areas confers increased asthma morbidity even after adjusting for ethnicity, age, and gender. Higher exposure to household pests, such as cockroaches and mice, pollutants and tobacco smoke exposure, poverty, material hardship, poor-quality housing, differences in health care quality, medication compliance, and heath care access also contribute to increased asthma morbidity in this population. Since 1991, the National Institutes of Allergy and Infectious Diseases established research networks: the National Cooperative Inner-City Asthma Study (NCICAS), the Inner-City Asthma Study (ICAS), and the Inner-City Asthma Consortium (ICAC), to improve care for this at risk population. The most striking finding of the NCICAS is the link between asthma morbidity and the high incidence of allergen sensitization and exposure, particularly cockroach. The follow-up ICAS confirmed that reductions in household cockroach and dust mite were associated with reduction in the inner-city asthma morbidity. The ICAC studies have identified that omalizumab lowered fall inner-city asthma exacerbation rate; however, the relationship between inner-city asthma vs immune system dysfunction, respiratory tract infections, prenatal environment, and inner-city environment is still being investigated. Although challenging, certain interventions for inner-city asthma children have shown promising results. These interventions include family-based interventions such as partnering families with asthma-trained social workers, providing guidelines driven asthma care as well as assured access to controller medication, home-based interventions aim at elimination of indoor allergens and tobacco smoke exposure, school-based asthma programs, and computer/web-based asthma programs.

Influence of viral infection on the relationships between airway cytokines and lung function in asthmatic children

BACKGROUND

Few longitudinal studies examine inflammation and lung function in asthma. We sought to determine the cytokines that reduce airflow, and the influence of respiratory viral infections on these relationships.

METHODS

Children underwent home collections of nasal lavage during scheduled surveillance periods and self-reported respiratory illnesses. We studied 53 children for one year, analyzing 392 surveillance samples and 203 samples from 85 respiratory illnesses. Generalized estimated equations were used to evaluate associations between nasal lavage biomarkers (7 mRNAs, 10 proteins), lung function and viral infection.

RESULTS

As anticipated, viral infection was associated with increased cytokines and reduced FVC and FEV1. However, we found frequent and strong interactions between biomarkers and virus on lung function. For example, in the absence of viral infection, CXCL10 mRNA, MDA5 mRNA, CXCL10, IL-4, IL-13, CCL4, CCL5, CCL20 and CCL24 were negatively associated with FVC. In contrast, during infection, the opposite relationship was frequently found, with IL-4, IL-13, CCL5, CCL20 and CCL24 levels associated with less severe reductions in both FVC and FEV1.

CONCLUSIONS

In asthmatic children, airflow obstruction is driven by specific pro-inflammatory cytokines. In the absence of viral infection, higher cytokine levels are associated with decreasing lung function. However, with infection, there is a reversal in this relationship, with cytokine abundance associated with reduced lung function decline. While nasal samples may not reflect lower airway responses, these data suggest that some aspects of the inflammatory response may be protective against viral infection. This study may have ramifications for the treatment of viral-induced asthma exacerbations.

Open-label, cluster randomised controlled trial and economic evaluation of a brief letter from a GP on unscheduled medical contacts associated with the start of the school year: the PLEASANT trial

BACKGROUND

Asthma is seasonal with peaks in exacerbation rates in school-age children associated with the return to school following the summer vacation. A drop in prescription collection in August is associated with an increase in the number of unscheduled contacts after the school return.

OBJECTIVE

To assess whether a public health intervention delivered in general practice reduced unscheduled medical contacts in children with asthma.

DESIGN

Cluster randomised trial with trial-based economic evaluation. Randomisation was at general practice level, stratified by size of practice. The intervention group received a letter from their general practitioner (GP) in late July outlining the importance of (re)taking asthma medication before the return to school. The control group was usual care.

SETTING

General practices in England and Wales.

PARTICIPANTS

12 179 school-age children in 142 general practices (70 randomised to intervention).

MAIN OUTCOME

Proportion of children aged 5-16 years who had an unscheduled contact in September. Secondary endpoints included collection of prescriptions in August and medical contacts over 12 months (September-August). Economic endpoints were quality-adjusted life-years gained and health service costs.

RESULTS

There was no evidence of effect (OR 1.09; 95% CI 0.96 to 1.25 against treatment) on unscheduled contacts in September. The intervention increased the proportion of children collecting a prescription in August by 4% (OR 1.43; 95% CI 1.24 to 1.64). The intervention also reduced the total number of medical contacts between September-August by 5% (incidence ratio 0.95; 95% CI 0.91 to 0.99).The mean reduction in medical contacts informed the health economics analyses. The intervention was estimated to save £36.07 per patient, with a high probability (96.3%) of being cost-saving.

CONCLUSIONS

The intervention succeeded in increasing children collecting prescriptions. It did not reduce unscheduled care in September (the primary outcome), but in the year following the intervention, it reduced the total number of medical contacts.

TRIAL REGISTRATION NUMBER

ISRCTN03000938; Results.

Interventions for autumn exacerbations of asthma in children

BACKGROUND

Asthma exacerbations in school-aged children peak in autumn, shortly after children return to school following the summer holiday. This might reflect a combination of risk factors, including poor treatment adherence, increased allergen and viral exposure, and altered immune tolerance. Since this peak is predictable, interventions targeting modifiable risk factors might reduce exacerbation-associated morbidity and strain upon health resources. The peak occurs in September in the Northern Hemisphere and in February in the Southern Hemisphere.

OBJECTIVES

To assess the effects of pharmacotherapy and behavioural interventions enacted in anticipation of school return during autumn that are designed to reduce asthma exacerbations in children during this period.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, reference lists of primary studies and existing reviews, and manufacturers' trial registries (Merck, Novartis and Ono Parmaceuticals). We searched databases from their inception to 1 December 2017, and imposed no restriction on language of publication.

SELECTION CRITERIA

We included all randomised controlled trials comparing interventions aimed specifically at reducing autumn exacerbations with usual care, (no systematic change in management in preparation for school return). We included studies providing data on children aged 18 years or younger.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened records identified by the search and then extracted data and assessed bias for trials meeting the inclusion criteria. A third review author checked for accuracy and mediated consensus on disagreements. The primary outcome was proportion of children experiencing one or more asthma exacerbations requiring hospitalisation or oral corticosteroids during the autumn period.

MAIN RESULTS

Our searches returned 546 trials, of which five met our inclusion criteria. These studies randomised 14,252 children to receive either an intervention or usual care. All studies were conducted in the Northern Hemisphere. Three interventions used a leukotriene receptor antagonist, one used omalizumab or a boost of inhaled corticosteroids, and the largest study, (12,179 children), used a medication reminder letter. Whilst the risk of bias within individual studies was generally low, we downgraded the evidence quality due to imprecision associated with low participant numbers, poor consistency between studies, and indirect outcome ascertainment.A US study of 513 children with mild/severe asthma and allergic sensitisation was the only study to provide data for our primary outcome. In this study, the proportion of participants experiencing an exacerbation requiring oral corticosteroids or hospital admission in the 90 days after school return was significantly reduced to 11.3% in those receiving omalizumab compared to 21.0% in those receiving placebo (odds ratio 0.48, 95% confidence interval 0.25 to 0.92, moderate-quality evidence). The remaining studies used alternative exacerbation definitions. When data from two leukotriene receptor antagonist studies with comparable outcomes were combined in a random-effects model, there was no evidence of an effect upon exacerbations. There was no evidence that a seasonal medication reminder letter decreased unscheduled contacts for a respiratory diagnosis between September and December.Four studies recorded adverse events. There was no evidence that the proportion of participants experiencing at least one adverse event differed between intervention and usual care groups. Lack of data prevented planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Seasonal omalizumab treatment from four to six weeks before school return might reduce autumn asthma exacerbations. We found no evidence that this strategy is associated with increased adverse effects other than injection site pain, but it is costly. There were no data upon which to judge the effect of this or other seasonal interventions on asthma control, quality of life, or asthma-related death. In future studies definitions of exacerbations should be provided, and standardised where possible. To investigate possible differential effects according to subgroup, participants in future trials should be well characterised with respect to baseline asthma severity and exacerbation history in addition to age and gender.

PLEASANT: Preventing and Lessening Exacerbations of Asthma in School-age children Associated with a New Term - a cluster randomised controlled trial and economic evaluation

BACKGROUND

Asthma episodes and deaths are known to be seasonal. A number of reports have shown peaks in asthma episodes in school-aged children associated with the return to school following the summer vacation. A fall in prescription collection in the month of August has been observed, and was associated with an increase in the number of unscheduled contacts after the return to school in September.

OBJECTIVE

The primary objective of the study was to assess whether or not a NHS-delivered public health intervention reduces the September peak in unscheduled medical contacts.

DESIGN

Cluster randomised trial, with the unit of randomisation being 142 NHS general practices, and trial-based economic evaluation.

SETTING

Primary care.

INTERVENTION

A letter sent (n = 70 practices) in July from their general practitioner (GP) to parents/carers of school-aged children with asthma to remind them of the importance of taking their medication, and to ensure that they have sufficient medication prior to the start of the new school year in September. The control group received usual care.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of children aged 5-16 years who had an unscheduled medical contact in September 2013. Supporting end points included the proportion of children who collected prescriptions in August 2013 and unscheduled contacts through the following 12 months. Economic end points were quality-adjusted life-years (QALYs) gained and costs from an NHS and Personal Social Services perspective.

RESULTS

There is no evidence of effect in terms of unscheduled contacts in September. Among children aged 5-16 years, the odds ratio (OR) was 1.09 [95% confidence interval (CI) 0.96 to 1.25] against the intervention. The intervention did increase the proportion of children collecting a prescription in August (OR 1.43, 95% CI 1.24 to 1.64) as well as scheduled contacts in the same month (OR 1.13, 95% CI 0.84 to 1.52). For the wider time intervals (September-December 2013 and September-August 2014), there is weak evidence of the intervention reducing unscheduled contacts. The intervention did not reduce unscheduled care in September, although it succeeded in increasing the proportion of children collecting prescriptions in August as well as having scheduled contacts in the same month. These unscheduled contacts in September could be a result of the intervention, as GPs may have wanted to see patients before issuing a prescription. The economic analysis estimated a high probability that the intervention was cost-saving, for baseline-adjusted costs, across both base-case and sensitivity analyses. There was no increase in QALYs.

LIMITATION

The use of routine data led to uncertainty in the coding of medical contacts. The uncertainty was mitigated by advice from a GP adjudication panel.

CONCLUSIONS

The intervention did not reduce unscheduled care in September, although it succeeded in increasing the proportion of children both collecting prescriptions and having scheduled contacts in August. After September there is weak evidence in favour of the intervention. The intervention had a favourable impact on costs but did not demonstrate any impact on QALYs. The results of the trial indicate that further work is required on assessing and understanding adherence, both in terms of using routine data to make quantitative assessments, and through additional qualitative interviews with key stakeholders such as practice nurses, GPs and a wider group of children with asthma.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN03000938.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 93. See the HTA programme website for further project information.

Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index

BACKGROUND

A Seasonal Asthma Exacerbation Predictive Index (saEPI) was previously reported based on 2 prior National Institute of Allergy and Infectious Diseases Inner City Asthma Consortium trials.

OBJECTIVE

This study sought to validate the saEPI in a separate trial designed to prevent fall exacerbations with omalizumab therapy.

METHODS

The saEPI and its components were analyzed to characterize those who had an asthma exacerbation during the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study. We characterized those inner-city children with and without asthma exacerbations in the fall period treated with guidelines-based therapy (GBT) in the absence and presence of omalizumab.

RESULTS

A higher saEPI was associated with an exacerbation in both the GBT alone (P < .001; area under the curve, 0.76) and the GBT + omalizumab group (P < .01; area under the curve, 0.65). In the GBT group, younger age at recruitment, higher total IgE, higher blood eosinophil percentage and number, and higher treatment step were associated with those who had an exacerbation compared with those who did not. In the GBT + omalizumab group, younger age at recruitment, increased eosinophil number, recent exacerbation, and higher treatment step were also associated with those who had an exacerbation. The saEPI was associated with a high negative predictive value in both groups.

CONCLUSIONS

An exacerbation in children treated with GBT with or without omalizumab was associated with a higher saEPI along with higher markers of allergic inflammation, treatment step, and a recent exacerbation. Those that exacerbated on omalizumab had similar features with the exception of some markers of allergic sensitization, indicating a need to develop better markers to predict poor response to omalizumab therapy and alternative treatment strategies for children with these risk factors. The saEPI was able to reliably predict those children unlikely to have an asthma exacerbation in both groups.

Clinical relevance of IgE-mediated sensitization against the mould Alternaria alternata in children with asthma

Background:

Asthma in childhood has a prevalence of 5–10% in Germany and severe asthma accounts for about 5% in this patient group. Positive predictive values for severe asthma are atopy, a positive family history and sensitizations against inhalative allergens. Alternaria is an important inhalative allergen and sensitization is suspected to correlate with severe and lethal asthma. We investigated the prevalence and impact of Alternaria sensitization in paediatric asthma.

Methods:

We reviewed paediatric patients with a diagnosis of low-grade, moderate and severe asthma. Data collection included concomitant atopic diseases, sensitization profiles, family history and prior hospitalization for asthma exacerbation.

Results:

A total of 207 paediatric patients (aged 1–17 years) were included in the study. Overall, 25% had low-grade asthma, 31% moderate and 44% severe asthma and 26% were formerly hospitalized. Alternaria sensitization was the most common in moulds, although without significant correlation with hospitalization and severe asthma. Alternaria sensitization increased with age and was significantly associated with co-sensitization against other moulds, grass pollen and cat epithelia. Allergic rhinitis was significantly correlated with hospitalization, independent of Alternaria sensitization.

Conclusions:

Alternaria sensitization was common and increased with age. No significant correlation was found between asthma degree, hospitalization rates and sensitization profiles. Alternaria sensitization demonstrated no isolated risk factor for severe asthma and hospitalization.

A comparison of seasonal trends in asthma exacerbations among children from geographic regions with different climates

BACKGROUND

The fall peak in childhood asthma exacerbations is thought to be related to an increase in viral infections and allergen exposure when children return to school. Whether the seasonality of asthma attacks among children from different geographic regions follows similar trends is unclear.

OBJECTIVE

To compare seasonal trends in asthma exacerbations among school-age children who lived in different geographic locations, with different climates, within the United States.

METHODS

Hospital billing data bases were examined to determine the monthly number of school-age children who were hospitalized or treated in the emergency department (ED) for asthma exacerbations. Data from four cities within three states were compared. Climate data were obtained from archives of the National Climate Data Center, U.S. Department of Commerce.

RESULTS

An annual peak in asthma exacerbations was observed during the fall months (September through November) among children who lived in Charlottesville, Virginia, as well as throughout the state of Virginia. An increase in exacerbations, which peaked in November, was observed for exacerbations among children who lived in Tucson, Arizona, and Yuma, Arizona. In contrast, exacerbations among children from New Orleans, Louisiana, increased in September but remained elevated throughout the school year. Although there was annual variation in the frequency of exacerbations over time, the seasonal patterns observed remained similar within the locations from year to year. A nadir in the frequency of attacks was observed during the summer months in all the locations.

CONCLUSION

Seasonal peaks for asthma exacerbations varied among the children who lived in geographic locations with different climates, and were not restricted to the beginning of the school year.

Reducing Exacerbations in the Inner City: Lessons from the Inner-City Asthma Consortium (ICAC)

Asthma exacerbations are important components of asthma morbidity. The Inner-City Asthma Consortium was established in the early 1990s to identify risk factors for and to evaluate treatments to reduce asthma symptoms and exacerbations. Early studies identified atopy and inadequate treatment as important drivers of asthma morbidity. Later studies demonstrated that good adherence to guidelines-based asthma care could virtually eliminate symptoms and reduce but not eliminate exacerbations. Looking at exacerbations by season, risk factors were found to vary across the different seasons. Of the 7 factors identified, allergic status and pulmonary functions were found to be important for exacerbations in all seasons, but allergy had its strongest effect in the fall season. Therefore, additional therapy directed at reducing the role of allergy was evaluated and found to significantly reduce exacerbations even in participants with good symptom control when receiving guidelines-based therapy. Despite this year around aggressive therapy, exacerbations remain albeit at a lower level and with less seasonal variation. Another strategy, the short term use of therapy aimed at reducing the role of allergy begun before the fall season and focused on individuals at high risk for exacerbations, was found to be an effective approach to minimize exacerbations and to limit the amount of therapy necessary.

Impact of a multi-trigger intervention on seasonal patterns of asthma symptoms in inner city children

OBJECTIVES

Peaks in childhood asthma symptoms and asthma morbidity occur universally in the fall and late winter/early spring. This study examines whether there is a time of the year best suited to implement environmental interventions to attenuate this pattern.

METHODS

From September 2006 to June 2010, mid-Atlantic inner-city children asthmatics with 1 asthma-related hospitalization (IP) or 2 emergency (ED) visits the year prior to enrollment received 5 in-home self-management education sessions which included multi-trigger avoidance techniques and supplies. Children's daily asthma symptoms were recorded for 12 months by caregivers.

RESULTS

One-hundred and thirty-six children (48%) completed 12 months of symptoms diaries. Symptom days were reduced by 4.5 days at 12 months follow-up (p < 0.001). Symptom severity improved with a decreased severity score of 29.0 to 7.9 at month 12 (p < 0.001). Sixty-one percent of patients with ≥2 ED visits at baseline dropped to 0-1visits (p < 0.001). Eighty percent of patients with ≥1 IP visits dropped to 0 visits at 12 months (p < 0.001). Patients who received intervention in the summer months had half the average monthly symptoms score (10.8) as those who received intervention in the spring months (20.8). When controlling for environment and morbidity, the summer enrolled group had a significantly lower (p = 0.021) symptom score than those in other seasons.

CONCLUSION

Home self-management/environmental interventions for this cohort appear to have the greatest effect for those receiving the intervention in the summer and fall. The largest impact occurs in the summer cohort. Further studies with a control group are necessary to confirm these findings.

Seasonal risk factors for asthma exacerbations among inner-city children

BACKGROUND

Asthma exacerbations remain common, even in children and adolescents, despite optimal medical management. Identification of host risk factors for exacerbations is incomplete, particularly for seasonal episodes.

OBJECTIVE

We sought to define host risk factors for asthma exacerbations unique to their season of occurrence.

METHODS

This is a retrospective analysis of patients aged 6 to 20 years who comprised the control groups of the Asthma Control Evaluation study and the Inner City Anti-IgE Therapy for Asthma study. Univariate and multivariate models were constructed to determine whether patients' demographic and historical factors, allergic sensitization, fraction of exhaled nitric oxide values, spirometric measurements, asthma control, and treatment requirements were associated with seasonal exacerbations.

RESULTS

The analysis included 400 patients (54.5% male; 59.0% African American; median age, 13 years). Exacerbations occurred in 37.5% of participants over the periods of observation and were most common in the fall (28.8% of participants). In univariate analysis impaired pulmonary function was significantly associated with greater odds of exacerbations for all seasons, as was an exacerbation in the previous season for all seasons except spring. In multivariate analysis exacerbation in the previous season was the strongest predictor in fall and winter, whereas a higher requirement for inhaled corticosteroids was the strongest predictor in spring and summer. The multivariate models had the best predictive power for fall exacerbations (30.5% variance attributed).

CONCLUSIONS

Among a large cohort of inner-city children with asthma, patients' risk factors for exacerbation vary by season. Thus information on individual patients might be beneficial in strategies to prevent these seasonal events.

Can meteorological factors forecast asthma exacerbation in a paediatric population?

BACKGROUND

Asthma exacerbations attended in emergency departments show a marked seasonality in the paediatric age. This seasonal pattern can change from one population to another and the factors involved are poorly understood.

OBJECTIVES

To evaluate the association between meteorological factors and schooling with asthma exacerbations in children attended in the paediatric emergency department of a district hospital.

METHODS

We conducted a retrospective review of the medical records of children 5-14 years of age attended for asthma exacerbations during a 4-year period (2007-2011). Climatic data were obtained from a weather station located very close to the population studied. The number of asthma exacerbations was correlated to temperature, barometric pressure, relative humidity, rainfall, wind speed, wind distance, solar radiation, water vapour pressure and schooling, using regression analyses.

RESULTS

During the study period, 371 children were attended for asthma exacerbations; median age was eight years (IQR: 6-11), and 59% were males. Asthma exacerbations showed a bimodal pattern with peaks in spring and summer. Maximum annual peak occurred in week 39, within 15 days from school beginning after the summer holidays. A regression model with mean temperature, water vapour pressure, relative humidity, maximum wind speed and schooling could explain 98.4% (p<0.001) of monthly asthma exacerbations.

CONCLUSIONS

The combination of meteorological factors and schooling could predict asthma exacerbations in children attended in a paediatric emergency department.

Findings from a community-based asthma education fair for Latino caregivers

OBJECTIVE

To assess limited English proficiency (LEP) asthma caregiver quality of life (QoL), skills retention and healthcare utilization after an asthma education fair (AEF).

METHODS

A language concordant AEF was conducted at a Latino community center. LEP caregivers of children 1-12 years old and an established asthma diagnosis participated in three skill stations: (a) medication recognition and administration, (b) peak flow use (if child ≥ 5 years) and (c) action plan dissemination. Spacers, peak flow meters and individualized action plans were distributed. A validated, pediatric asthma caregiver quality of life questionnaire (PACQLQ-Spanish version) was administered. Baseline data was compared to follow-up interview data at three and six months after the AEF. Mean PACQLQ scores were analyzed with Wilcoxon signed-rank test and nominal paired data with McNemar's test.

RESULTS

We analyzed data from 18 caregivers able to speak English well (22%), not well (28%) or not at all (50%). After three months, improved caregiver QoL was experienced (51 vs. 72, p<0.01). No differences were observed in medication recognition, spacer and peak flow use or peak flow interpretation. After six months, mean school days missed due to asthma decreased (4.1 vs. 0.4, p<0.01). Mean clinic visits, emergency department visits and hospitalizations remained unchanged.

CONCLUSIONS

Implementation of a community-based AEF with action plan administration can be beneficial for LEP caregivers and their children. QoL improvements to emotional wellbeing and activity limitations were observed, and lower rates of school absenteeism were reported. Caregiver ability to accurately identify medications was not enhanced.

Preventing and lessening exacerbations of asthma in school-age children associated with a new term (PLEASANT): study protocol for a cluster randomised control trial

BACKGROUND

Within the UK, during September, there is a pronounced increase in the number of unscheduled medical contacts by school-aged children (4-16 years) with asthma. It is thought that that this might be caused by the return back to school after the summer holidays, suddenly mixing with other children again and picking up viruses which could affect their asthma. There is also a drop in the number of prescriptions administered in August. It is possible therefore that children might not be taking their medication as they should during the summer contributing to them becoming ill when they return to school.It is hoped that a simple intervention from the GP to parents of children with asthma at the start of the summer holiday period, highlighting the importance of maintaining asthma medication can help prevent increased asthma exacerbation, and unscheduled NHS appointments, following return to school in September.

METHODS/DESIGN

PLEASANT is a cluster randomised trial. A total of 140 General Practices (GPs) will be recruited into the trial; 70 GPs randomised to the intervention and 70 control practices of "usual care". An average practice is expected to have approximately 100 children (aged 4-16 with a diagnosis of asthma) hence observational data will be collected on around 14000 children over a 24-month period. The Clinical Practice Research Datalink will collect all data required for the study which includes diagnostic, prescription and referral data.

DISCUSSION

The trial will assess whether the intervention can reduce exacerbation of asthma and unscheduled medical contacts in school-aged children associated with the return to school after the summer holidays. It has the potential to benefit the health and quality of life of children with asthma while also improving the effectiveness of NHS services by reducing NHS use in one of the busiest months of the year.An exploratory health economic analysis will gauge any cost saving associated with the intervention and subsequent impacts on quality of life. If results for the intervention are positive it is hoped that this could be adopted as part of routine care management of childhood asthma in general practice.

TRIAL REGISTRATION

Current controlled trials: ISRCTN03000938 (assigned 19/10/12) http://www.controlled-trials.com/ISRCTN03000938/.

UKCRN ID

13572.

Lack of a relation between serum 25-hydroxyvitamin D concentrations and asthma in adolescents

BACKGROUND

Decreased 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with an increased prevalence and severity of asthma and a lower response to inhaled corticosteroids.

OBJECTIVE

The objective was to determine the association between serum 25(OH)D concentrations and asthma prevalence, severity, and response to asthma treatment.

DESIGN

Secondary analyses were conducted in 2 samples of adolescents 12-20 y of age: 1) NHANES 2001-2006 (n = 6487), a cross-sectional nationally representative sample of the US population, and 2) a cohort of inner-city adolescents with asthma managed prospectively for 46 wk with guidelines-based therapy in the Asthma Control Evaluation (ACE; n = 226) trial.

RESULTS

Mean (±SD) serum 25(OH)D concentrations in the NHANES and ACE samples were lower in African Americans than in non-African Americans (NHANES: 14.9 ± 6.5 compared with 23.0 ± 8.4 ng/mL, P < 0.0001; ACE: 11.2 ± 6.9 compared with 15.8 ± 7.1 ng/mL, P < 0.0001). In the NHANES sample, mean concentrations did not differ between participants without and with asthma (African Americans: 14.9 ± 6.4 compared with 15.0 ± 6.6 ng/mL, respectively, P = 0.87; non-African Americans: 23.0 ± 8.5 compared with 23.6 ± 8.2 ng/mL, respectively, P = 0.16). In the ACE models that used either a predefined cutoff (<20 ng/mL) or linear regression, 25(OH)D concentrations showed either no relation or minor contradictory correlations with indicators of asthma severity, treatment requirements, spirometry, or atopy/inflammation.

CONCLUSION

In 2 samples of adolescents, overall serum 25(OH)D concentrations were low and were not consistently associated with the presence of asthma, multiple asthma characteristics, asthma morbidity, or response to treatment. The ACE trial was registered at clinicaltrials.gov as NCT0011441.

The Head-off Environmental Asthma in Louisiana (HEAL) study--methods and study population

BACKGROUND

In the city of New Orleans, Louisiana, and surrounding parishes (NOLA), children with asthma were perilously impacted by Hurricane Katrina as a result of disrupted health care, high home mold and allergen levels, and high stress.

OBJECTIVES

The Head-off Environmental Asthma in Louisiana (HEAL) study was conducted to examine relationships between the post-Katrina environment and childhood asthma in NOLA and assess a novel asthma counselor intervention that provided case management and guidance for reducing home mold and allergen levels.

METHODS

Children (4-12 years old) with moderate-to-severe asthma were recruited from NOLA schools. Over 1 year, they received two clinical evaluations, three home environmental evaluations, and the asthma intervention. Quarterly end points included symptom days, medication use, and unscheduled emergency department or clinic visits. A community advisory group was assembled and informed HEAL at all phases.

RESULTS

Of the children (n = 182) enrolled in HEAL, 67% were African American, and 25% came from households with annual incomes < $15,000. HEAL children were symptomatic, averaging 6.6 symptom days in the 2 weeks before baseline, and had frequent unscheduled visits to clinics or emergency departments (76% had at least one unscheduled visit in the preceding 3 months). In this report, we describe study design and baseline characteristics of HEAL children.

CONCLUSIONS

Despite numerous challenges faced by investigators, study staff, and participants, including destroyed infrastructure, disrupted lives, and lost jobs, HEAL was successful in terms of recruitment and retention, the high quality of data collected that will provide insight into asthma-allergen relationships, and the asthma intervention. This success was attributable to using an adaptive approach and refining processes as needed.

Estimation of asthma incidence among low-income children in Texas: a novel approach using Medicaid claims data

Few recent estimates of childhood asthma incidence exist in the literature, although the importance of incidence surveillance for understanding asthma risk factors has been recognized. Asthma prevalence, morbidity, and mortality reports have repeatedly shown that low-income children are disproportionately impacted by the disease. The aim of this study was to demonstrate the utility of Medicaid claims data for providing statewide estimates of asthma incidence. Medicaid analytic extract (MAX) data for Texas children aged 0-17 years enrolled in Medicaid between 2004 and 2007 were used to estimate incidence overall and by age group, gender, race, and county of residence. A ≥13-month period of continuous enrollment was required in order to distinguish incident from prevalent cases identified in the claims data. The age-adjusted incidence of asthma was 4.26/100 person-years during 2005-2007, higher than reported in other populations. Incidence rates decreased with age, were higher for males than females, differed by race, and tended to be higher in rural than urban areas. This study demonstrates the utility of Medicaid analytic extract data for estimating asthma incidence and describes the methodology required for a population with unstable enrollment.

Limited agreement between current and long-term asthma control in children: the PACMAN cohort study

BACKGROUND

Several studies have shown that predictors of asthma treatment outcomes differ depending on the definition of the outcome chosen. This provides evidence that different outcomes studied may reflect distinct aspects of asthma control. To assess predictors of asthma control, we need firm outcome phenotypes. The aim of this study was to investigate the association between measurements of current and long-term asthma control.

METHODS

We included 527 children using inhaled corticosteroids participating in the Pharmacogenetics of Asthma medication in Children: Medication with ANti-inflammatory effects cohort. Current asthma control (previous week) was defined using the Asthma Control Questionnaire. Long-term asthma control was based on Global Initiative for Asthma guidelines. Not well-controlled asthma in a season was defined as ≥ 3 of the following items present in a season: (i) day-time or (ii) night-time symptoms, (iii) limitations in activities, and (iv) rescue medication use. Asthma control during (i) the previous season and (ii) the year preceding the pharmacy visit was used as long-term asthma control definitions. Current and long-term asthma control were compared to investigate agreement.

RESULTS

Long-term uncontrolled asthma rates were highest in autumn and winter (50%) and lowest in summer (32%) (p < 0.05). Overall agreement between current and long-term asthma control was limited (66% for previous season and 68% for previous year).

CONCLUSION

Congruence between current and long-term asthma control was limited. Furthermore, we showed significant seasonal differences. It is therefore important to calculate asthma control over a longer period of time, instead of using current asthma control as indicator.

Seasonality of medical contacts in school-aged children with asthma: association with school holidays

OBJECTIVES

To assess the seasonality of medical contacts in children with asthma, to compare England with Scotland, and to assess the impact of medication compliance on the frequency of medical contacts.

STUDY DESIGN

A retrospective study taken from the General Practice Research Database of daily medical contacts from 1999 to 2005 in a population of school-aged (5-16 years) children with a diagnosis of asthma, and age- and gender-matched controls.

PRIMARY OUTCOME MEASURE

All unscheduled medical contacts. Prescription frequency for inhaled corticosteroids over the same period was also assessed.

RESULTS

Data from 76,924 children were analyzed. There was an increase in unscheduled medical contacts for all children on return to school in September. Unscheduled medical contacts occurred almost twice as frequently in children with asthma compared with non-asthmatic children. The frequency of medical contacts in children with asthma could be predicted from the frequency of medical contacts in non-asthmatic children. In the 3 months from September to December, unscheduled medical contacts were disproportionately greater than would be predicted for children with asthma relative to non-asthmatic children in both England and Scotland. The rise in medical contacts in Scotland preceded that in England by approximately 14 days, reflecting the earlier date for returning to school. The number of prescriptions for inhaled corticosteroids decreased in August. A higher incidence of unscheduled medical contacts was noted during September in those not receiving a prescription in August.

CONCLUSIONS

Returning to school after the summer break is associated with a sharp increase in unscheduled medical contacts in school-aged children, particularly in those with asthma. This follows a decrease in the number of prescriptions for inhaled corticosteroids. It is suggested that at least part of the excess numbers of unscheduled contacts in children with asthma is because they do not maintain their inhaled corticosteroids over the summer holidays.

Differences in Environmental Control and Asthma Outcomes Among Urban Latino, African American, and Non-Latino White Families

Latino and African American children with asthma are at increased risk for asthma morbidity compared with non-Latino White children. Environmental control (ie, environmental exposures and family strategies to control them) may contribute to greater asthma morbidity for ethnic minority children living in urban environments. This study examined ethnic differences in a semi-structured assessment of environmental control, associations between environmental control and asthma outcomes (asthma control, functional limitation, and emergency department [ED] use), and ethnic differences in environmental triggers in a sample of urban Latino, African American, and non-Latino White families. One hundred thirty-three children (6-13 years of age) and their caregivers completed demographic questionnaires, measures of asthma control and morbidity, and a semi-structured interview assessing environmental control. Reported environmental control differed significantly by ethnicity (P<0.05), with Latino families reporting higher levels of environmental control. Reported environmental control was significantly associated with asthma control (P<0.017) and functional limitation (P<0.017). Reported environmental control and ED use were significantly associated in Latino families (P<0.05). Non-Latino White and African American families reported more secondhand smoke exposure than Latino families (P<0.001). Latino families reported more optimal home environmental control than other ethnic groups. Substantial ethnic differences in asthma triggers suggest that observed ethnic disparities in asthma may be due, at least in part, to differences in the home environment.

Asthma symptoms in pediatric patients: differences throughout the seasons

INTRODUCTION

Seasonal variation in asthma has been widely recognized. The aim of this study was to describe seasonal patterns of asthma symptoms and asthma medication use in a cohort of pediatric asthma medication users and to study determinants of seasonal childhood asthma.

METHODS

For this study, 602 children participating in the Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects) cohort were included. Parents were asked about their child's respiratory symptoms and quick-reliever medication use over the past year. Logistic regression analysis was used to study determinants of seasonality in asthma control (the level of disease control based on symptoms, limitations in activities, and rescue medication use).

RESULTS

There was a decline in asthma symptoms and asthma medication use during the summer period and a peak occurred from autumn to spring. The prevalence of wheeze ranged from 32% in summer to 56% in autumn. The prevalence of respiratory symptoms and medication use was significantly lower during summer (p < .0001). Oral steroids and antibiotics use and strong parental necessity beliefs were associated with uncontrolled asthma, regardless of seasonality. Allergic rhinitis was associated with an increased risk of uncontrolled asthma during spring [odds ratio (OR): 1.9; 95% confidence interval (CI): 1.3-2.8] and summer (OR: 1.9; 95% CI: 1.2-3.0). Eczema was associated with a higher risk of uncontrolled asthma during autumn (OR: 1.5; 95% CI: 1.0-2.2) and winter (OR: 1.3; 95% CI: 1.0-1.9).

CONCLUSION

We showed seasonal patterns in asthma symptoms and medication use. Associations were shown between allergic rhinitis and asthma control during spring/summer and eczema was associated with uncontrolled asthma during autumn/winter. Seasonality in asthma morbidity and health-care use is most likely associated with atopic constitution and viral infections, which are common during fall, winter, and spring.

Frequency of prescription of inhaled corticosteroids to children with asthma in U.S. emergency departments

OBJECTIVES

This study examined how frequently inhaled corticosteroids (ICS) are prescribed at discharge in U.S. emergency departments (EDs) for children presenting with asthma exacerbations.

METHODS

This was a secondary analysis of the 2005-2007 National Hospital Ambulatory Medical Care Survey (NHAMCS) database for ED visits by children 2 to 21 years old with acute respiratory symptoms and a diagnosis of asthma exacerbation. The authors determined the proportion of visits with an ICS prescription at discharge, and the associations between demographic, clinical factors, and ICS prescriptions were analyzed using logistic regression.

RESULTS

Between 2005 and 2007, there were 2,288,874 estimated visits by children 2 to 21 years old to U.S. EDs with asthma exacerbations, and ICS were prescribed at discharge at 4.0% of these visits (95% confidence interval [CI] = 2.4% to 5.5%). In the logistic regression model, ICS were more likely to be prescribed in the fall (adjusted odds ratio [OR] vs. spring 3.3; 95% CI = 1.0 to 11.0). Otherwise, there were no pertinent demographic or clinical factors associated with ICS prescription.

CONCLUSIONS

Inhaled corticosteroids are infrequently prescribed for children with asthma at discharge from U.S. EDs. Other than the fall season, there are no identified demographic or clinical factors associated with the likelihood of ICS prescriptions. ED clinicians should consider interventions to increase ICS prescriptions for children with persistent asthma.

Randomized trial of omalizumab (anti-IgE) for asthma in inner-city children

BACKGROUND

Research has underscored the effects of exposure and sensitization to allergens on the severity of asthma in inner-city children. It has also revealed the limitations of environmental remediation and guidelines-based therapy in achieving greater disease control.

METHODS

We enrolled inner-city children, adolescents, and young adults with persistent asthma in a randomized, double-blind, placebo-controlled, parallel-group trial at multiple centers to assess the effectiveness of omalizumab, as compared with placebo, when added to guidelines-based therapy. The trial was conducted for 60 weeks, and the primary outcome was symptoms of asthma.

RESULTS

Among 419 participants who underwent randomization (at which point 73% had moderate or severe disease), omalizumab as compared with placebo significantly reduced the number of days with asthma symptoms, from 1.96 to 1.48 days per 2-week interval, a 24.5% decrease (P<0.001). Similarly, omalizumab significantly reduced the proportion of participants who had one or more exacerbations from 48.8 to 30.3% (P<0.001). Improvements occurred with omalizumab despite reductions in the use of inhaled glucocorticoids and long-acting beta-agonists.

CONCLUSIONS

When added to a regimen of guidelines-based therapy for inner-city children, adolescents, and young adults, omalizumab further improved asthma control, nearly eliminated seasonal peaks in exacerbations, and reduced the need for other medications to control asthma. (Funded by the National Institute of Allergy and Infectious Diseases and Novartis; ClinicalTrials.gov number, NCT00377572.).

Translation of a pediatric asthma-management program into a community in Connecticut

OBJECTIVES

We assessed whether a successful asthma-management program could be translated into pediatrician's offices, improve care, and reduce medical services use.

METHODS

Pediatrician's offices from 6 communities in Connecticut were trained, and all children aged 6 months or older were eligible for enrollment. Quality measures included enrollment numbers, appropriate use of anti-inflammatory therapy, and distribution of a written treatment plan. Medical services utilization data for Medicaid-insured children were expressed as relative rates (RRs) (95% confidence intervals [CIs]) before and after enrollment, and we used historical and contemporaneous comparisons and generalized estimating equations.

RESULTS

A total of 51 practices and 297 clinicians enrolled 32 680 children from 2002 to 2007; 10 467 had asthma, of whom 4354 were insured with Medicaid. Children with persistent asthma experienced decreases in the number of hospitalizations (RR: 0.51 [95% CI: 0.39-0.65]) and emergency-department visits (RR: 0.70 [95% CI: 0.68-0.84]), and there was no change in number of outpatient visits (RR: 0.99 [95% CI: 0.9-1.10]). Inhaled corticosteroid use doubled, appropriate use of anti-inflammatory therapy increased to 96%, and 94% of the children were given a written treatment plan.

CONCLUSIONS

General pediatricians can successfully implement an asthma-management program that is effective in improving care for large numbers of children.

Trends in hospital admissions due to asthma in north-west Spain from 1995 to 2007

PURPOSE

Asthma is the most common chronic disease in childhood. Hospital admissions in the child population appear to be reducing in different populations.

METHODS

We have retrospectively analysed admissions into hospitals in our region due to asthma in a 0 to 14 years population, between the years 1995 and 2007. The age, sex, date of admission, and length of hospital stay of each patient was recorded and analysed.

RESULTS

A total of 9106 admissions (64% males) have been included. A gradual trend towards a reduction in admissions is observed during the period analysed. There were more admissions in 1996, with 2.91 per thousand inhabitants, gradually reducing to 1.33 per thousand in 2007. There were more admissions in May and between September and December, being less frequent in July and August. The mean stay in this period was 4.18 days, which was stable during the whole period of the study. Older children tended to have a longer hospital stay.

CONCLUSIONS

Our study shows that admissions due to childhood asthma tend to be decreasing, particularly due to younger males, with no change in the length of hospital stay. Asthma exacerbations seemed to be associated with infections and exposure to allergens.

Role of emerging respiratory viruses in children with severe acute wheezing

BACKGROUND

Acute wheezing episodes are frequently associated with respiratory viral infections in children. However, the role of the recently described respiratory viruses is not yet fully understood.

OBJECTIVE

The main objective of this study was to estimate the frequency of human metapneumovirus (HMPV), human bocavirus (HBoV), and 14 other respiratory viruses in hospitalized children with acute wheezing.

METHODS

A prospective study was conducted on children <14 years old, admitted with an acute expiratory wheezing episode from September 2005 to June 2008. Viruses were detected in nasopharyngeal aspirates by polymerase chain reaction. Clinical data were prospectively recorded.

RESULTS

A viral pathogen was identified in 444 (71%) out of 626 hospitalized acute wheezing episodes. Respiratory syncytial virus (RSV) was the most frequently detected (27%), followed by rhinovirus (24%), adenovirus (17.8%), HBoV (16%), and HMPV (4.7%). The rate of viral detection was significantly higher in infants (77.3%), than in older children (59.8%) (P < 0.001). RSV and HBoV were more prevalent in infants (P < 0.001) than in older children.

CONCLUSION

The most prevalent viruses found in severe acute wheezing episodes were RSV and rhinovirus not only in childhood, but also in infancy. However, other emerging viruses such as HBoV and metapneumovirus also play an important role in wheezing episodes.

Differential effects of outdoor versus indoor fungal spores on asthma morbidity in inner-city children

BACKGROUND

Although sensitization to fungal allergens is prevalent in inner-city children with asthma, the relationship between fungal exposure and morbidity is poorly understood.

OBJECTIVE

We examined relationships between fungal sensitization, exposure, and asthma morbidity in inner-city children.

METHODS

Participants were 5 to 11 years old and enrolled in the Inner-City Asthma Study. This report includes the subset of children with at least 1 positive skin test (PST) response to a fungal allergen extract; for these children, indoor and outdoor airborne culturable fungi levels were measured at baseline and throughout the 2-year study. Asthma morbidity measures were collected prospectively. The primary outcome was symptom days per 2 weeks.

RESULTS

At baseline, children with a PST response to a fungal allergen extract had significantly more symptom days compared with those without a PST response to any fungal allergen extract (6.3 vs 5.7 days per 2 weeks, P = .04). During the study, increases in total fungal exposure and indoor Penicillium species exposure were associated with increases in symptom days and asthma-related unscheduled visits. Indoor exposures to total fungi and to Penicillium species were associated with significant increases in unscheduled visits, even after controlling for outdoor fungal levels. Adverse effects associated with exposure to a specific fungus were stronger among children with PST responses to that fungal allergen extract compared with those seen in children with negative skin test responses.

CONCLUSION

Outdoor fungal exposure is primarily associated with increased asthma symptoms and increased risk of exacerbations in this population.

Dispensing of fluticasone propionate/salmeterol combination in the summer and asthma-related outcomes in the fall

BACKGROUND

Asthma exacerbations occur year-round; however, peak asthma-related events occur in the fall and are frequently associated with viral respiratory infections.

OBJECTIVE

To compare the rates of asthma-related emergency department (ED) visits and hospitalizations in the fall (September, October, November) between users and nonusers of fluticasone propionate plus salmeterol in a single inhaler (FSC) in the preceding summer.

METHODS

This was a retrospective, observational study using health care claims from a large managed care database. Patients age 4 to 55 years with both a medical claim for asthma and a pharmacy claim for FSC were categorized into 3 age groups: children (4-11 years), adolescents (12-18 years), and adults (19-55 years).

RESULTS

There were 201,973 observations of FSC dispensings and 184,143 observations without FSC. Across all age groups, summertime dispensings of FSC were associated with a significantly lower (P < .001) risk of an asthma-related ED visit (4-11 years: adjusted odds ratio [OR], 0.54, 95% CI, 0.49-0.60; 12-18 years: OR, 0.59, 95% CI, 0.54-0.64; 19-55 years: OR, 0.53, 95% CI, 0.51-0.55) or hospitalization (4-11 years: OR, 0.43, 95% CI, 0.35-0.54; 12-18 years: OR, 0.49, 95% CI, 0.40-0.60; 19-55 years: OR, 0.61, 95% CI, 0.57-0.65) in the subsequent fall. This protective effect persisted even for patients with fall dispensings of FSC. The risk of oral corticosteroid dispensing in the fall was also significantly reduced in all age groups.

CONCLUSION

Summertime dispensings of FSC were associated with a decreased risk of serious asthma-related outcomes in the subsequent fall. Continuous use of FSC before seasonal viral exposure may decrease seasonally related exacerbations.

Changes in the health burden of a national sample of children with asthma

This paper focused on the extent to which factors that are modifiable by health policies or provider recommendations influenced the level and changes in the burden of childhood asthma. Demographic factors, access to health care services, and asthma control activities were posited to potentially influence the level and changes in health burden of children with asthma. The Medical Expenditure Panel Survey data from 1996-1999 on 3-11 year old U.S. children with asthma (N=784) were used. The findings of multilevel models of perceived burden indicated unfavorable trajectories among those families who had public health insurance. Asthma control activities were associated with favorable trajectories of both perceived and objectively measured burden. These findings emphasized the significance of asthma control and access to high quality and stable health care services as health policy targets.

Distribution and seasonality of rhinovirus and other respiratory viruses in a cross-section of asthmatic children in Trinidad, West Indies

Background

Childhood asthma in the Caribbean is advancing in prevalence and morbidity. Though viral respiratory tract infections are reported triggers for exacerbations, information on these infections with asthma is sparse in Caribbean territories. We examined the distribution of respiratory viruses and their association with seasons in acute and stable asthmatic children in Trinidad.

Methods

In a cross-sectional study of 70 wheezing children attending the emergency department for nebulisation and 80 stable control subjects (2 to 16 yr of age) in the asthma clinic, nasal specimens were collected during the dry (n = 38, January to May) and rainy (n = 112, June to December) seasons. A multitarget, sensitive, specific high-throughput Respiratory MultiCode assay tested for respiratory-virus sequences for eight distinct groups: human rhinovirus, respiratory syncytial virus, parainfluenza virus, influenza virus, metapneumovirus, adenovirus, coronavirus, and enterovirus.

Results

Wheezing children had a higher [χ² = 5.561, p = 0.018] prevalence of respiratory viruses compared with stabilized asthmatics (34.3% (24) versus (vs.) 17.5% (14)). Acute asthmatics were thrice as likely to be infected with a respiratory virus (OR = 2.5, 95% CI = 1.2 – 5.3). The predominant pathogens detected in acute versus stable asthmatics were the rhinovirus (RV) (n = 18, 25.7% vs. n = 7, 8.8%; p = 0.005), respiratory syncytial virus B (RSV B) (n = 2, 2.9% vs. n = 4, 5.0%), and enterovirus (n = 1, 1.4% vs. n = 2, 2.5%). Strong odds for rhinoviral infection were observed among nebulised children compared with stable asthmatics (p = 0.005, OR = 3.6, 95% CI = 1.4 – 9.3,). RV was prevalent throughout the year (Dry, n = 6, 15.8%; Rainy, n = 19, 17.0%) and without seasonal association [χ² = 0.028, p = 0.867]. However it was the most frequently detected virus [Dry = 6/10, (60.0%); Rainy = 19/28, (67.9%)] in both seasons.

Conclusion

Emergent wheezing illnesses during childhood can be linked to infection with rhinovirus in Trinidad's tropical environment. Viral-induced exacerbations of asthma are independent of seasons in this tropical climate. Further clinical and virology investigations are recommended on the role of infections with the rhinovirus in Caribbean childhood wheeze.

Seasonal patterns in health care use and pharmaceutical claims for asthma prescriptions for preschool- and school-aged children

BACKGROUND

In children, hospitalization for asthma is reported to have a distinct seasonal pattern with peaks coincident with the start of school. Although guidelines indicate that asthma controller medications should be used daily, there is limited information on actual seasonal patterns of medication use.

OBJECTIVE

To describe seasonal patterns of asthma-related health care use and asthma controller and reliever medication claims in children.

METHODS

An ecological analysis was conducted of data collected from records for children aged 2 to 12 years from 2002 through 2004 from an automated research database of insurance claims from a large US health care plan. Seasonal patterns for health care use and estimates of prescription asthma controller and reliever use were determined for preschool-aged children (aged 2-5 years) and school-aged children (aged 6-12 years). Rates were constructed by week; deviations from annual mean rates were used to determine peaks in use. Results were confirmed using Poisson regression models, modeling for rates within age group, with factors for week, year, and regions.

RESULTS

Emergency department and outpatient visits and hospitalizations were lowest during summer; rates increased beginning in September, peaking in October or November. Asthma controller and reliever medication claims increased beginning in September, peaking in December. Rates also were elevated in February.

CONCLUSIONS

The data suggest that children who reduce their asthma medications during the summer do not resume taking medications until signs or symptoms of asthma worsen. The summer hiatus and other factors may contribute to seasonal increases in health care use and in asthma medication prescriptions, particularly in the fall.

An examination of interventions to reduce respiratory health and injury hazards in homes of low-income families

We evaluated whether combining asthma trigger reduction with housing structural repairs, device disbursement and education in low-income households with children would improve self-reported respiratory health and reduce housing-related respiratory health and injury hazards (convenience sample of n=67 homes with 63 asthmatic and 121 non-asthmatic children). At baseline, a visual assessment of the home environment and a structured occupant interview were used to examine 29 potential injury hazards and 7 potential respiratory health hazards. A home-specific intervention was designed to provide the children's parents or caretakers with the knowledge, skills, motivation, supplies, equipment, and minimum housing conditions necessary for a healthy and safe home. The enrolled households were primarily Hispanic and owned their homes. On average, 8 injury hazards were observed in the homes at baseline. Four months following intervention, the average declined to 2.2 hazards per home (p<0.001), with 97% of the parents reporting that their homes were safer following the interventions. An average of 3.3 respiratory health hazards were observed in the homes at baseline. Four months following intervention, the average declined to 0.9 hazards per home (p<0.001), with 96% of parents reporting that the respiratory health of their asthmatic children improved. A tailored healthy homes improvement package significantly improves self-reported respiratory health and safety, reduces respiratory health and injury hazards, and can be implemented in concert with a mobile clinical setting.

Factors associated with asthma exacerbations during a long-term clinical trial of controller medications in children

BACKGROUND

Asthma exacerbations are a common cause of critical illness in children.

OBJECTIVE

To determine factors associated with exacerbations in children with persistent asthma.

METHODS

Regression modeling was used to identify historical, phenotypic, treatment, and time-dependent factors associated with the occurrence of exacerbations, defined by need for oral corticosteroids or emergency or hospital care in the 48-week Pediatric Asthma Controller Trial study. Children age 6 to 14 years with mild-to-moderate persistent asthma were randomized to receive either fluticasone propionate 100 microg twice daily (FP monotherapy), combination fluticasone 100 microg AM and salmeterol twice daily, or montelukast 5 mg once daily.

RESULTS

Of the 285 participants randomized, 48% had 231 exacerbations. Using a multivariate analysis, which included numerous demographic, pulmonary, and inflammatory parameters, only a history of an asthma exacerbation requiring a systemic corticosteroid in the past year (odds ratio [OR], 2.10; P < .001) was associated with a subsequent exacerbation during the trial. During the trial, treatment with montelukast versus FP monotherapy (OR, 2.00; P = .005), season (spring, fall, or winter vs summer; P < or = .001), and average seasonal 5% reduction in AM peak expiratory flow (OR, 1.21; P = .01) were each associated with exacerbations. Changes in worsening of symptoms, beta-agonist use, and low peak expiratory flow track together before an exacerbation, but have poor positive predictive value of exacerbation.

CONCLUSION

Children with mild-to-moderate persistent asthma with previous exacerbations are more likely to have a repeat exacerbation despite controller treatment. Inhaled corticosteroids are superior to montelukast at modifying the exacerbation risk. Available physiologic measures and biomarkers and diary card tracking are not reliable predictors of asthma exacerbations.

Physician perspectives regarding annual influenza vaccination among children with asthma

OBJECTIVE

National guidelines have historically varied for influenza vaccination of children with asthma, depending on asthma severity. This study aims to explore perspectives of primary care physicians regarding influenza vaccination practices for children with persistent versus intermittent asthma.

METHODS

A cross-sectional survey was mailed to general pediatricians (n = 300) and family physicians (n = 300) in primary care offices in Michigan in 2006. The main outcome measures included physicians' influenza vaccination recommendations and reasons for nonadministration of influenza vaccine to children with asthma for the 2005-2006 influenza season.

RESULTS

Ninety-six percent of respondents (N = 320) reported routinely recommending influenza vaccination for children with persistent asthma; fewer (82%) reported routinely recommending influenza vaccination for those with intermittent asthma. The adjusted odds of recommending influenza vaccination for intermittent asthma patients was significantly higher among pediatricians versus family physicians (adjusted odds ratio 3.49, 95% confidence interval, 1.68-7.22), controlling for other practice characteristics. Regardless of specialty, physicians with more than 25 asthma patients were more likely than those with fewer asthma patients to routinely recommend influenza vaccination. Physicians who do not routinely recommend influenza vaccination to children with intermittent asthma were more likely to cite overlooking discussion of influenza vaccine during the visit (50% vs 13%, respectively; P < .0001) as a reason for lack of vaccination.

CONCLUSIONS

Influenza vaccination practices of primary care physicians reflect the inconsistencies historically found in national recommendations. Further research is warranted to determine whether the recent clarification of recommendations of the National Asthma Education and Prevention Program (NAEPP) to remove distinctions by asthma severity is associated with a reduction in missed opportunities to vaccinate.

Impact of admission-day crowding on the length of stay of pediatric hospitalizations

OBJECTIVE

Increased crowding may affect the care that is delivered to hospitalized patients, particularly around the time of admission. There is little information about the impact of admission-day crowding on the outcome of children who are hospitalized with common pediatric conditions.

METHODS

A population cohort was constructed of children who were aged 1 to 17 years and were hospitalized in Pennsylvania and New York between April 1, 1996, and June 30, 1998, with 1 of 19 common pediatric conditions (N = 116,235). Condition-specific Cox regression and logit models were developed to estimate the effect of admission-day occupancy on 4 outcome measures after controlling for illness severity and site of care: length of stay; 21-day readmission; prolonged stay or a stay longer than the typical, uncomplicated stay for that condition as a measure of care delivered to patients with uncomplicated courses; and conditional length of stay as a measure of care delivered to patients whose stays are prolonged.

RESULTS

For children who were admitted with respiratory disease, increasing admission-day occupancy from 60% to 100% was associated with a 0.25-day increase in the average length of stay. Increased admission-day occupancy above 60% was also associated with higher odds of a prolonged stay but not with a change in 21-day readmission rates or conditional length of stay. For children who were admitted with nonrespiratory conditions, increased admission-day occupancy was not associated with changes to any length-of-stay outcome.

CONCLUSIONS

Increased admission-day occupancy was associated with longer lengths of stay for less complicated respiratory admissions but not for children who were admitted with the most serious conditions. These results suggest that medical professionals, during times of increased workload, first focus their attention on more acutely ill children with a complicated course and thus delay treatment of children who have less complicated courses but require time-consuming management and treatment.

Air quality and pediatric asthma-related emergencies

BACKGROUND

Previous studies suggest a relationship between air pollutants, aeroallergens, and asthma exacerbations.

OBJECTIVE

To simultaneously examine the role of seasonality, air quality, aeroallergens, and climate on asthma-related pediatric emergency department (ED) visits.

METHODS

A retrospective 4-year study of asthma-related ED visits was conducted.

RESULTS

September had the highest number of visits (p < 0.01). There were lower temperatures and precipitation (p < 0.01) and higher tree and weed pollen levels (p = 0.05) on days with more visits (p = 0.05), while grass pollen, mold, ozone, NO2, and PM2.5 levels showed no significant differences.

CONCLUSIONS

Asthma-related visits were associated with aeroallergens and climatic factors and not air-quality factors.

Evaluation of Community Action Against Asthma: a community health worker intervention to improve children's asthma-related health by reducing household environmental triggers for asthma

This article describes the evaluation of a community-based participatory research (CBPR) community health worker (CHW) intervention to improve children's asthma-related health by reducing household environmental triggers for asthma. After randomization to an intervention or control group, 298 households in Detroit, Michigan, with a child, aged 7 to 11, with persistent asthma symptoms participated. The intervention was effective in increasing some of the measures of lung function (daily nadir Forced Expiratory Volume at one second [p = .03] and daily nadir Peak Flow [p = .02]), reducing the frequency of two symptoms ("cough that won't go away," "coughing with exercise"), reducing the proportion of children requiring unscheduled medical visits and reporting inadequate use of asthma controller medication, reducing caregiver report of depressive symptoms, reducing concentrations of dog allergen in the dust, and increasing some behaviors related to reducing indoor environmental triggers. The results suggest a CHW environmental intervention can improve children's asthma-related health, although the pathway for improvement is complex.

Health effects of indoor nitrogen dioxide and passive smoking on urban asthmatic children

BACKGROUND

Nitrogen dioxide (NO(2)) and environmental tobacco smoke (ETS) have been associated with adverse respiratory effects.

OBJECTIVE

We sought to assess the effect of NO(2) and ETS on asthma morbidity among children in inner-city environments.

METHODS

Asthmatic children between the ages of 4 and 9 years had exposure to NO(2) and ETS measured by using Palmes tubes in the home and urinary cotinine. A baseline interview and telephone assessments at 3, 6, and 9 months evaluated health service use, asthma symptoms, and peak flow rates.

RESULTS

Gas stoves were present in 87.8% of 469 homes. The median level of indoor NO(2) was 29.8 ppb compared with the US national outdoor median of 18 ppb. Of 1444 children, 48% had urinary cotinine/creatinine ratios of greater than 30 ng/mg. The median level of the cotinine/creatinine ratio was 42.4 ng/mg in smoking homes compared with 18.0 ng/mg in nonsmoking homes. The relative risk for asthma symptoms with increased NO(2) exposure was 1.75 (95% CI, 1.10-2.78) in children who did not have positive skin test responses. Higher NO(2) exposure resulted in lower peak flows during colder months (relative risk, 1.46; 95% CI, 1.07-1.97). Higher ETS exposure in colder months was weakly associated with lower peak flows (relative risk, 1.21; 95% CI, 0.99-1.47). There was no effect of ETS exposure on symptoms or use of health care services.

CONCLUSION

Higher levels of indoor NO(2) are associated with increased asthma symptoms in nonatopic children and decreased peak flows.

CLINICAL IMPLICATIONS

Interventions to reduce NO(2) exposure, such as venting of gas stoves, might help reduce asthma morbidity.