Specific Social, Environmental Factors May Influence Incidence Rates of Childhood Asthma with Recurrent Exacerbations

Authors: Rachel L. Miller; Christine C. Johnson, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) Program, Office of The Director, National Institutes of Health.

Why was this study needed?

While the prevalence of asthma has been reported widely in the United States and elsewhere, studies on childhood asthma incidence rates within specific populations and across various types of asthma and age ranges have been relatively sparse. Describing the incidence rates of ARE across various pediatric populations is a critical first step for identifying potential risk factors and causes.

What were the study results?

In this study, investigators wanted to gather more information about factors that influence the rates of childhood asthma with recurrent exacerbations (ARE)—a subtype of asthma where children experience frequent, severe episodes of asthma.

ARE incidence rates were highest among children ages 2-4 years old, and among non-Hispanic Black and Hispanic Black children. ARE rates were also higher among children living in the Northeast and Midwest compared to those living in the West. Children with a parental history of asthma had ARE rates 2.9 times greater compared to those with no parental history.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the impact?

Higher incidence rates of ARE among young children, non-Hispanic Black and Hispanic Black children, and children living in the Northeast and Midwest suggest that differential environmental exposures may play a significant role in the onset of recurring asthma issues in children. ARE rates are consistently higher among children with a parental history of asthma, especially for young children, which may be due to a combination of genetic, environmental, and family lifestyle factors.

Who was involved?

The research team leveraged data from 17,246 children born between 1990 and 2017 who were enrolled in 60 ECHO research sites in the U.S. and Puerto Rico. Child participants or their caregivers reported whether and when the child had an asthma diagnosis and any oral corticosteroids prescribed from a health care provider. Incidence rates of ARE were based on reports of systemic (not inhaled) corticosteroid use.

Of the 4,114 children diagnosed with asthma during this study, there were 2,061 children with at least one asthma episode when they used oral steroid medication; 734 of these children had 2 or more asthma episodes with steroid medication use and met the conditions for ARE.

What happened during the study?

The researchers calculated the incidence rates of ARE for the study population as a whole, along with the rates for subsets of the population defined by the year of ARE diagnosis, the decade they were born, their age and sex, their race and ethnicity, their residence at birth, and their parents’ history of asthma. The researchers followed the children from birth until they developed ARE, reached the age of 20 years or the study period ended. The study identified children who developed ARE based on at least two reports of systemic steroid medication use at any time during the entire follow-up period. Children who received asthma diagnoses before age 5 years were required to have confirmation after 5 years, either by a parent or caregiver, adolescent self-report of asthma symptoms, hospitalization, emergency department or urgent care visit for asthma, provider visits due to asthma, or asthma medication use.

What happens next?

ECHO researchers are planning new studies that examine key early environmental exposures that could contribute to ARE, including viral respiratory tract infections, indoor allergens, environmental tobacco smoke, air pollution, stress, socioeconomic status, and where children live.

Where can I learn more?

Access the full journal article, titled “Incidence Rates of Childhood Asthma with Recurrent Exacerbations in the U.S. Environmental influences on Child Health Outcomes (ECHO) Program,” in The Journal of Allergy and Clinical Immunology.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published March 25, 2023

Access the associated article.

Download this summary

Specific Social, Environmental Factors May Influence Incidence Rates of Childhood Asthma with Recurrent Exacerbations

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

<< Back to Research Summaries

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

Author(s): Kohei Hasegawa, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

What were the study results?

Bronchiolitis is a wheezing illness usually caused by a lung infection such as Respiratory Syncytial Virus (RSV). During this study, researchers found that the hospitalized infants with bronchiolitis were more likely to develop asthma by the age of 12 years when compared to hospitalized infant without bronchiolitis. The researchers also saw that this effect was stronger for non-Hispanic White and non-Hispanic Black infants, compared with Hispanic infants.

What was the study's impact?

This is the first nationwide investigation that demonstrates the role of severe bronchiolitis during infancy on influencing long-term childhood asthma risk and identifies subgroups of children who are most at risk for developing asthma following bronchiolitis during infancy. These results could help future investigations to identify what factors may influence the association between severe bronchiolitis and childhood asthma risk across different demographic groups, which could advance the development of targeted prevention strategies for childhood asthma.

Why was this study needed?

Severe bronchiolitis is the most common reason for hospitalization in U.S. infants younger than 2 years old. Many studies have shown that severe bronchiolitis, requiring hospitalization during infancy, is a risk factor for developing childhood asthma. However, these studies have been too narrow to evaluate how severe bronchiolitis during infancy affects childhood asthma risk in various demographic subgroups.

Who was involved?

The researchers analyzed data from 11,762 infants enrolled in 53 ECHO research sites across the United States. All of these infants were hospitalized at age 12 months or younger between 2001-2021. Of these infants, 10% were hospitalized with bronchiolitis. One of the participating ECHO cohorts selectively enrolled children with a parental history of asthma.

What happened during the study?

The researchers collected data from participating infants under 12 months old on caregiver-reported hospitalization for bronchiolitis. The researchers then used data on caregiver-reported asthma diagnosis prior to age 12 to evaluate the relationship between severe bronchiolitis and childhood asthma to determine how this relationship may be affected by major demographic and clinical factors.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What happens next?

Future studies are needed to investigate the reasons underlying the links among infant bronchiolitis, demographic and clinical factors, and the development of asthma. These findings not only provide an evidence base for early identification of children who are at high risk for asthma but also offer opportunities for early preventive interventions in this large, high-risk population.

Where can I learn more?

Access the full journal article, titled “Association of Severe Bronchiolitis during Infancy with Childhood Asthma Development: An Analysis of the ECHO Consortium,” in Biomedicines.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published: December 22, 2022

Download this summary

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

ECHO Study Links Poor Neighborhood Conditions With Higher Risk of Asthma in Children

<< Back to Research Summaries

ECHO Study Links Poor Neighborhood Conditions With Higher Risk of Asthma in Children

Author(s): Antonella Zanobetti, Patrick H. Ryan, et al

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Of the 5,809 children studied, 46% experienced wheezing in their first year of life, with 26% having wheezing through age 11. Diagnosis of asthma by age 11 varied by cohort, with an overall median prevalence of 25%. Children in neighborhoods with more people, and with more families with lower incomes, experienced more asthma and early and persistent wheezing. Black and Hispanic children remained at higher risk for asthma than White children, even in wealthier neighborhoods.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study suggests that neighborhood characteristics at birth and race/ethnicity play a role in the development of childhood wheezing and asthma. This information can help inform strategies to reduce childhood asthma, including strategies that address the socioeconomic factors that create higher risks for Black and Hispanic children.

Why was this study needed?

In the United States, Black and Hispanic children have higher rates of asthma compared to White children and more often live in communities where households struggle to meet their basic needs. The objective of this study was to explore how much neighborhood-level socioeconomic factors, like income and education, contribute to differences in childhood wheezing and asthma between Black, White, and Hispanic children.

Who was involved?

Almost 6,000 children across the United States born between the 1980s and 2010s.

What happened during the study?

The team used questionnaires and interviews to collect information such as wheezing and asthma occurrence, medical history, and demographics. Each child’s home address was matched to U.S. Census data for the decade closest to their birth year. Researchers studied how children’s race/ethnicity and their mother’s education level and smoking habits, plus their neighborhood socioeconomic conditions, were related to wheezing – a symptom involving whistling breathing sounds due to narrowed airways – and asthma.

Where can I learn more?

Access the full journal article, titled “Childhood Asthma Incidence, Early and Persistent Wheeze, and Neighborhood Socioeconomic Factors in the ECHO/CREW Consortium” in JAMA Pediatrics.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published May 23, 2022

Read the associated article.

Download this summary

ECHO Study Links Poor Neighborhood Conditions With Higher Risk of Asthma in Children

ECHO Study Identifies Demographics of Children Most Likely to Develop Asthma

<< Back to Research Summaries

ECHO Study Identifies Demographics of Children Most Likely to Develop Asthma

Author(s): Christine Cole Johnson and Aruna Chandran

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

The study found that children with at least one parent with a history of asthma had two to three times higher rates of asthma. This higher risk with family history of asthma mostly affected younger children, through four years old. The rates for boys went down with age, but rates for girls stayed about the same, so by the teenage years girls developed asthma more often than boys. Black children were diagnosed with asthma more than white children during preschool years, but less than white children after age 9-10 years.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study helps us understand what groups of children are more likely to get asthma. The research shows that young Black children and young children whose parents had asthma develop asthma more often than other groups. Researchers can work to develop new asthma programs to help keep children at highest risk from getting asthma.

Why was this study needed?

Childhood asthma is a major cause of suffering, missed school for children, and missed work for parents. Researchers and doctors need to understand who is more likely to get asthma, not just focus on who already has it, as other studies have done. Knowing this information is a step to finding out why certain kids get asthma and preventing it. Using information from children from diverse backgrounds in the United States, this paper describes which children developed asthma from early childhood through adolescence.

Who was involved?

Children younger than 18 years old taking part in 31 studies within the ECHO program

What happened during the study?

The research team found out the ages when children learned from a doctor they had asthma, and the children’s race, sex, and what state they lived in. It was also important to collect information on whether their parents had asthma or not.

What happens next?

Researchers should work on asthma prevention programs for very young children, especially Black children and those whose parents have had asthma.

Where can I learn more?

If you would like to learn more about asthma in children, please visit the Centers for Disease Control and Prevention or the National Heart Lung and Blood Institute (NHLBI).

Access the full journal article, titled “Childhood Asthma Incidence Rate Patterns from the ECHO Consortium: Identifying High-Risk Groups for Primary Prevention.”

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published: May 17, 2021

Download this summary

ECHO Study Identifies Demographics of Children Most Likely to Develop Asthma

ECHO Study Identifies Genetic Underpinnings of Wheezing Patterns Linked to Asthma

<< Back to Research Summaries

ECHO Study Identifies Genetic Underpinnings of Wheezing Patterns Linked to Asthma

Author(s): Brian Hallmark, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health under Award Number 5UH3 OD023282.

What were the study results?

Four wheezing patterns were seen among the children: (1) infrequent—few wheezing episodes in the first three years then none after that; (2) transient—some wheezing in first few years then fewer and gone by around age six; (3) late onset—little wheezing in the first few years then slowly happens more often; (4) persistent—many wheezing episodes over the first 11 years.

About half of children experience wheezing before three years old, and 62% wheezed in the first 10 years of life. The wheezing may start because of a viral infection (like the common cold). Many children only wheeze as preschoolers. AA children were more likely than European American (EA) children to have persistent wheezing.

Several small gene changes were connected to transient, late onset, and persistent wheezing in EA children, but for both AA and EA children, only two specific small gene changes were connected with a greater likelihood of the child wheezing after the first three years.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

For the first time, it is reported that genetic changes associated with childhood asthma are also associated with all wheezing patterns in young children. These wheezing patterns were found consistently in children located in different cities and born in different decades.

Wheezing in young children is often a result of common respiratory viruses that affect breathing. These findings, together with what we know about the genes associated with asthma, suggest that some of these small gene changes may be connected to a higher risk of colds and other viral airway infections that trigger wheezing in small children.

This study also highlights the importance of including multiple race/ancestry groups in genetic studies to understand how small changes in genes are connected to different health outcomes in diverse groups.

Why was this study needed?

Previous studies have shown that many children wheeze during the first few years of life—some later stop, while others can develop ongoing asthma. Other children do not wheeze during early life but still develop asthma later during childhood. Understanding where these patterns come from may shed light on how asthma begins and help doctors identify children who might need help earlier. Other studies identified small changes in specific genes that could be responsible for some cases of childhood asthma. This study tried to find possible connections between those small gene changes and different wheezing patterns in children. This is also the first study that looks at how small genetic changes may relate to specific patterns of wheezing in African American (AA) children.

Who was involved?

Data came from children enrolled at birth in seven different studies across the US. Nearly 3,700 children who experienced at least three wheezing events were included, and researchers analyzed the genes of 1,928 of these children. About 32% of these children were AA. Each study site used questionnaires and interviews to collect information from children and their parents over many years.

What happened during the study?

The team collected patient characteristics and data on wheezing and asthma and pulled those data together to group each child based on when and how often they wheezed from birth to age 11. Each site also collected DNA samples from the children and sent them to be analyzed for small changes in genes associated with asthma. The researchers used statistics to identify four different wheezing patterns and connect them with specific genetic changes.

What happens next?

The team is looking at possible associations between children’s insulin levels, genetic variations, and the development of asthma in childhood.

Where can I learn more?

Access the full journal article, titled “Chromosome 17q12-21 Variants Are Associated with Multiple Wheezing Phenotypes in Childhood,” in the American Journal of Respiratory and Critical Care Medicine.

Additional Details

This project would not have been possible without ECHO CREW support, as the data came from seven separate birth cohorts brought together by that program. In particular, combining those datasets was essential to getting a large enough sample size to include AA children.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Read the corresponding article.

Published: April 1, 2021

Download this summary

ECHO Study Identifies Genetic Underpinnings of Wheezing Patterns Linked to Asthma