School Closures in the United States and Severe Respiratory Illnesses in Children: A Normalized Nationwide Sample.

OBJECTIVES

To determine the association between nationwide school closures and prevalence of common admission diagnoses in the pediatric critical care unit.

DESIGN

Retrospective cohort study.

SETTING

National database evaluation using the Virtual Pediatric Systems LLC database.

PATIENTS

All patients admitted to the PICU in 81 contributing hospitals in the United States.

MEASUREMENTS AND MAIN RESULTS

Diagnosis categories were determined for all 110,418 patients admitted during the 20-week study period in each year (2018, 2019, and 2020). Admission data were normalized relative to statewide school closure dates for each patient using geographic data. The "before school closure" epoch was defined as 8 weeks prior to school closure, and the "after school closure" epoch was defined as 12 weeks following school closure. For each diagnosis, admission ratios for each study day were calculated by dividing 2020 admissions by 2018-2019 admissions. The 10 most common diagnosis categories were examined. Significant changes in admission ratios were identified for bronchiolitis, pneumonia, and asthma. These changes occurred at 2, 8, and 35 days following school closure, respectively. PICU admissions decreased by 82% for bronchiolitis, 76% for pneumonia, and 76% for asthma. Nonrespiratory diseases such as diabetic ketoacidosis, status epilepticus, traumatic injury, and poisoning/ingestion did not show significant changes following school closure.

CONCLUSIONS

School closures are associated with a dramatic reduction in the prevalence of severe respiratory disease requiring PICU admission. School closure may be an effective tool to mitigate future pandemics but should be balanced with potential academic, economic, mental health, and social consequences.