A Symptom-Based Algorithm for Screening Preschool Children at Risk of Persistent Asthma Symptoms: The CHILD Cohort Study

Background: Asthma is difficult to diagnose in preschool children causing delays in treatment and long-term morbidity. This study aims to develop a short, symptom-based algorithm screening tool for preschool children at 3 years to predict asthma diagnosis, persistent symptoms and morbidity in later childhood. Methods: Developed in the CHILD study cohort, the algorithm uses clinical predictors at 3 years of age to identify children with asthma or persistent symptoms at 5 years and was evaluated against standardized specialist clinician diagnosis and the modified Asthma Predictive Index (mAPI). External validation was performed in the general population Raine cohort (Australia) and the high-risk CAPPS (Canadian) cohort. Predictive accuracy was measured by sensitivity, specificity, AUROC, positive predictive value, and negative predicted value. Findings: The algorithm applied at age 3 years in the CHILD cohort study outperformed physician assessments and the mAPI at age 3 in identifying children whose wheeze persisted to age 5 years (AUROC=0.94), or with an asthma diagnosis at 5 years (AUROC=0.73). It had similar predictive performance for persistent wheeze when validated in the external Raine (AUROC=0.82) and CAPPS (AUROC=0.87) cohorts. Finally, the algorithm outperformed physician diagnoses in predicting subsequent health care burden (ED visits/hospitalization for wheeze/asthma) to age 5 years. Conclusions: Our symptom-based algorithm identifies children at age 3 years likely to suffer from persistent wheeze symptoms and health care burden to 5 years of age. The algorithm could be easily incorporated in electronic medical records to alert physicians of children at high risk for asthma and asthma related morbidity. Funding Statement: Canadian Institutes of Health Research (CIHR), Allergy, Genes and Environment Network of Centers of Excellence (AllerGen NCE, Inc.), Don & Debbie Morrison, Women’s and Children Health Research Institute (WCHRI), Canada Research Chairs (CRC) Declaration of Interests: None. Ethics Approval Statement: This study was approved centrally by the Hamilton Integrated Research Ethics Board (HiREB #07-2929) and all local ethics boards.