All Children Left Behind: Drug Adherence and the COVID-19 Pandemic

We study the effect of the COVID-19 pandemic on chronic disease drug adherence. Focusing on asthma, we use a database that tracks the vast majority of prescription drug claims in the U.S. from 2018 to 2020. Using a difference-in-differences empirical specification, we compare monthly drug adherence in 2019 and 2020 for the set of chronic patients taking asthma medication before the onset of the pandemic. We find that the pandemic increased adherence for asthmatic adults by 10 percent. However, we find a sustained decrease in pediatric drug adherence that is most severe for the youngest children. By the end of 2020, drug adherence fell by 30 percent for children aged 0 to 5, by 12 percent for children aged 6 to 12, and 5 percent for children aged 13 to 18. These negative effects are persistent regardless of changes in medical need, socioeconomic factors, insurance coverage and access to health services. We provide suggestive evidence that the observed pediatric changes are likely driven by parental inattention.