Risk Factors for Asthma–Neurodevelopmental Disorder Multimorbidity in Canadian Children: A National Longitudinal Study

Background: Asthma and neurodevelopmental disorders (NMD) are associated. Understanding the risk factors that contribute to developing this multimorbidity are important to both clinical practice and public health. We used longitudinal data from a nationally representative sample to investigate risk factors for the development of asthma, NMD, and their multimorbidity.

Methods: Data was from the Canadian Health Survey of Children and Youth. Children were followed from 2019 to 2023 to track change in condition status (no asthma or NMD; asthma only; NMD only; both asthma and NMD). Survey responses about risk factors were assessed and associated with these changes.

Results: A greater proportion of children developed NMD than asthma. Having other chronic conditions was associated with increased odds of developing multimorbidity, while non-white ethnic background was protective. Allergies, regular alcohol use, and eating breakfast regularly were associated with increased risk of developing asthma while being born outside of Canada and having other chronic conditions were protective. Female sex, food insecurity, and allergies increased the risk of developing NMD while meeting sleep guidelines, eating breakfast regularly, and eating meals with family were protective.

Conclusions: We confirmed several risk factors of asthma, NMD, and multimorbidity as well as identified unexpected findings that may prompt further research.