Critical Windows in the Development of Asthma Endotypes and Phenotypes in High-Risk Toddlers

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to learn more about how asthma develops in early childhood. This will help doctors understand how to prevent and treat asthma better.

Official Title
-----------------
Critical Windows in the Development of Asthma Endotypes and Phenotypes in High-Risk Toddlers

Conditions
-----------------
Asthma in Children, Wheezing

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 18 months to 36 months at first research encounter For enrollment in Emergency Department (ED)/Inpatient Visit: Presentation to the ED/Inpatient with an acute wheezing episode AND either evidence of at least one prior wheezing episode documented in the electronic medical record (i.e., wheezing, pneumonitis, bronchiolitis, reactive airways disease, or asthma) that occurred ≥ 14 days from current episode, or caregiver report of one of the following: Child has had wheezing or whistling in the chest at any time in the past lasting at least 24 hours and occurring at least 14 days prior to the current ED visit Child has been treated with albuterol or used an inhaler or a nebulizer at least 14 days prior to the current ED visit Caregiver has been told that their child has bronchiolitis, asthma, or reactive airways disease at least 14 days prior to the current ED visit For enrollment in Visit 1: At least three separate wheezing episodes, separated by at least 14 consecutive days without a wheezing episode (wheezing lasting ≥ 24 hours), as reported by parent/caregiver or patient's care provider and/or documented in the patient's medical record Third episode may be at time of presentation to ED or admission as inpatient (IP) to hospital when recruitment would occur (Visit ED/IP) Bronchiolitis and wheezing/asthma exacerbations are considered wheezing episodes The wheezing episode does not require treatment with bronchodilators Live within a US Office of Management and Budget-defined Metropolitan Statistical Area (MSA) and meet at least one of these criteria: Have publicly funded health insurance AND/OR Live in a census tract within an MSA where ≥10% of families have income below the poverty level Exclusion Criteria: Wheeze attributed to alternative diagnoses other than bronchiolitis or asthma, including congenital anatomical abnormalities, foreign body aspiration, chronic lung disease of prematurity, other chronic lung disorders such as cystic fibrosis, and cardiac, immune, and gastrointestinal disorders. Gestational age < 32 weeks.

Ages Eligible for Study
-----------------
Minimum Age: 18 Months
Maximum Age: 36 Months

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnosis of persistent asthma | Children will be classified as having persistent asthma if at least 1 of the following 3 conditions are met: Doctor Diagnosis: a parent-reported physician's diagnosis of asthma between age 4 and 7 years plus asthma symptoms or the use of asthma controller medication for at least 6 of the past 12 months Lung Function: bronchodilator-induced improvement of forced expiratory volume in 1 second (FEV1) by 10% or more plus asthma symptoms or use of asthma controller medication for at least 6 of the past 12 months Symptoms: report in the past 12 months of 2 or more wheezing episodes, 2 or more doctor's office visits for asthma/wheeze, 1 or more hospitalizations for asthma/wheeze, or use of controller medications for at least 6 of the past 12 months. | At visit 5, after 4 years of participation in the longitudinal study | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
childhood asthma, recurrent wheeze, asthma phenotypes, asthma endotypes, asthma development