LATEBREAKER
Environment/Climate Change
Association between fine particulate matter (PM2.5) and severity of acute respiratory infections among young US children in the major cities in the United States: a claims-based cohort study Damien Foo* Damien Foo Annette K. Regan Seulkee Heo Eric B. Schneider Joseph Canner Michelle L. Bell
Background: Acute respiratory infections (ARIs) are a leading cause of morbidity and mortality among young children. Air pollution may play a role in the exacerbation of ARIs via inflammation, immunosuppression, and oxidative stress, yet this effect has been infrequently evaluated among young children.
Objectives: To evaluate the impact of short-term exposure to fine particulate matter (PM2.5) to ARI severity among children aged <5 years.
Methods: We analyzed data from a claims-based cohort of US children aged <5 years enrolled in a private health insurance plan who were diagnosed with an ARI between January 2018 and March 2020. We use daily monitored PM2.5 concentrations at the metropolitan statistical area level to estimate the short-term weekly exposure to PM2.5. We evaluated the association between short-term exposure to PM2.5 and the risk of hospital admissions and readmissions with an ARI, intensive care unit (ICU) admission, mechanical ventilation, prescription claim for antiviral medication, and length of stay using generalized linear models adjusting for individual-, ecological-, and community-level covariates.
Results: Of the 598,164 unique ARI episodes, we observed 3,511 antiviral prescription claims, 5,081 hospital admissions, 1,486 ICU admissions, 129 mechanical ventilations, and 61 hospital readmissions. The risk of an antiviral prescription claim increased by 11% (95% confidence interval [CI]: 1.07,1.15) per interquartile range increase in exposure to PM2.5 (3.37 µg/m3); this association was consistent irrespective of age group or influenza vaccination status. We observed a 6% and 11% increased risk of ICU admission (95% CI: 1.01, 1.10) and mechanical ventilation (95% CI: 1.06, 1.18), respectively, among children not vaccinated against influenza and no increase among vaccinated children.
Discussion: Short-term exposure to PM2.5 may contribute to ARI severity among young children. Influenza vaccination may modify the risk of severe ARI-associated outcomes.