The prevalence of childhood asthma: interpreting falling rates in the context of shifting measurement and the COVID-19 pandemic

Purpose of review

The estimated prevalence of childhood asthma in the United States, as measured by the National Health Information Survey (NHIS), has decreased by 30% since 2017. This review provides context for observed changes in asthma rates by describing recent shifts in NHIS data collection and analysis, and considers whether the COVID-19 pandemic might impact asthma prevalence in years to come.

Recent findings

The NHIS underwent a planned redesign in 2019 with updated sampling weights to better match the U.S. population. In early 2020, the COVID-19 pandemic resulted in unplanned modifications to NHIS implementation, which may have included fewer children from populations at a heightened risk for asthma. Decreasing prevalence estimates in recent years are likely at least in part due to these survey changes rather than true epidemiologic shift. However, pandemic-related changes to risk factors for childhood asthma (including exposure to rhinovirus infections and allergic sensitization) may also influence prevalence in the future.

Summary

Recent changes in estimated rates of childhood asthma in the USA are likely driven by changes to survey methods and implementation, both before and during the COVID-19 pandemic. Additional years of data are needed to determine whether a true shift in disease prevalence is occurring.