New Screening Tool Identifies Asthma Risk in Toddlers

Kristin Jenkins

October 12, 2022

A symptom-based screening tool can identify 2-year-olds at increased risk of asthma, persistent symptoms of wheeze, and health care burden by the age of 5, according to researchers.

The validated CHILDhood Asthma Risk Tool (CHART) determines high, moderate, or low risk of asthma based on symptoms reported before the age of 3 years. It also recommends follow-up.

Potentially, CHART could be used "to identify children who need monitoring, timely symptom control, and introduction of preventive therapies," said Padmaja Subbarao, MD, MSc, associate chief of clinical research at the Hospital for Sick Children, Toronto, and colleagues in JAMA Network Open.

"The implementation of CHART as a first-step screening tool in general practice could promote timely treatment control and, in turn, improve quality of life for patients and reduce the clinical and economic burden of asthma," they wrote.

Subbarao and colleagues developed CHART using data from parent questionnaires and 3- and 5-year clinic visits in the CHILD study. Children were categorized as "high risk" when they experienced two or more episodes of wheeze annually at both 3 and 5 years of age, concurrent with ED visits, hospitalizations, asthma medication, or frequent dry cough. Children with only cough episodes or with cough episodes plus one episode of wheeze in the past 12 months were categorized as "low risk."

"Our unique approach to classification of wheeze symptoms is important because it helps busy practitioners identify the smaller subset of children with more frequent or severe wheezing episodes who have a higher probability of continued symptoms and impaired lung function in adult life among most children with infrequent wheeze," Sabbarao and coauthors said.

Their diagnostic study to evaluate CHART's predictive capacity showed that the tool had the highest proportion of true-positive asthma at 5 years (sensitivity, 50.0%), compared with physicians' diagnosis at 3 years (sensitivity, 43.5%), and positive standardized modified Asthma Predictive Index (mAPI) at 3 years (sensitivity, 24.4%).

CHART also outperformed physician assessments and mAPI for predicting persistent wheeze at 5 years and provided the highest predictive capacity for subsequent health care use at 5 years of age. The study showed that it identified 20% more children with emergency department visits or hospitalizations than the standardized mAPI (sensitivity 45.5% vs. 25.0%), and approximately 10% more at-risk children than physician diagnosis.

"These findings are especially important given that many hospitalizations are avoidable if appropriate treatment and management of asthma are implemented at primary care," Subbarao and colleagues wrote.

CHART has been validated in two external cohorts: a general-population cohort of 2,185 children from the Raine Study in Australia at 5 years of age; and the other a high-risk cohort of 349 children from the Canadian Asthma Primary Prevention Study at 7 years of age.

"We want to highlight the importance of periodic monitoring of wheeze symptoms and simplify the identification of high-risk children for primary care providers and parents or caregivers," said Subbarao, who is director of the CHILD study and professor of pediatrics at the University of Toronto.

The tool "does not identify the underlying biology, which could impact the efficacy of our current standard asthma treatment," Subbarao emphasized. CHART has not been tested in low-prevalence settings or in countries in which the term "wheeze" is not commonly recognized, she added.

"CHART helps you focus your crystal ball a little bit, look into the future, and see what's going to happen," said Harold Farber, MD, a pediatric pulmonologist who was not involved in the study. "It's useful even if it just confirms what I'm already doing clinically."

Farber, who is professor of pediatrics at Baylor College of Medicine and the Texas Children's Hospital, Houston, cautioned that the predictive value of CHART is based on the diagnosis of asthma, and that this can differ across health care communities. "Between the extremes and what's considered borderline, there's a lot of diagnostic variation in what we call asthma," he explained in an interview. "The diagnosis is, to some extent, subjective."

However, Farber agreed that two or more wheezing episodes in the past 12 months — enough to require treatment — puts a child at very high risk for future wheezing. "Kids with a bunch of wheezing problems at 3 years are likely to have wheezing problems at 5. We have to think about what we can do for a toddler today to keep him from wheezing later."

CHART is simple to use, the investigators said. The information needed can be easily gathered through interviews and parent-reported questionnaires, then put into the electronic medical record to flag children at high risk for further investigation, and well as those at low or moderate risk for monitoring.

Parents and caregivers can also use CHART to document symptoms every 6 months in children older than 1 year of age, said Subbarao. This information can be brought to the attention of the doctor "to facilitate a deeper discussion," she suggested.

This study was funded by the Canadian Institutes of Health Research, Allergy, Genes and Environment Network of Centers of Excellence; Don and Debbie Morrison; Women's and Children Health Research Institute; and Canada Research Chairs. Dr Subbarao reported having no potential conflicts of interest. Coauthor Vanessa Breton, PhD, disclosed being employed by F. Hoffmann-La Roche Ltd., and coauthor Elinor Simons, MD, PhD, reported membership on the Sanofi-Genzyme Data Monitoring Board. No other conflicts of interest were reported by the study authors. Dr Farber disclosed having no potential conflicts of interest.

This article originally appeared on, part of the Medscape Professional Network.


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