593: PRE-COVID, COVID, AND POST-COVID TRENDS OF RSV AND INFLUENZA ACROSS GEOGRAPHIC REGIONS IN THE USA

Abstract

Introduction: Admissions to Pediatric Intensive Care Units (PICUs) for respiratory illnesses, particularly RSV and Influenza (INF), have decreased during the COVID-19 pandemic. The differences in trends for RSV and INF admissions to PICUs across different regions in the U.S. are unknown. Changes in these trends before (2014-19), during (2019-20), and towards the end of the pandemic (2021-22), and utilization patterns across regions have not been evaluated. This analysis aimed at addressing these questions. Methods: 874,066 USA PICU cases from the Virtual Pediatric Systems database (myvps.org), from Q1-2014 to Q2-2022, were used to study RSV and INF in patients < 18 years. The geographic regions according to U.S. Census definition included Mid-West (MW), Northeast (NE), South (S), and West (W). RSV and INF were defined by ICD-9 and ICD-10 codes. After removing low-risk patients (PRISM III POD < 0.004) the cohort size was 492,642. Segmented regression analysis (Muggeo 2016) was used to fit the trends in yearly rates for RSV and INF. Least-squares linear fits were applied to data segments before and after breakpoints (change in slope) to determine the correlation coefficients of each segment. Fisher’s Z-transform was used to investigate significant differences between segments before and after their respective breakpoints. Utilization amongst regions was done by ANCOVA analysis, and Bonferroni corrected p-values for the most prevalent procedures in the cohorts. Results: All regions showed an increase in RSV and INF between 2014-19, but decreasing during 2020-21. In 2021-22 all regions showed an increase trend in INF, but RSV increased only in MW and S compared to NE and W. Further analysis using RSV segmented regression revealed: MW, NE, and W breakpoints (positive to negative) in: 2018, 2019, and 2019, respectively. For INF, breakpoints for MW, NE, S, and W were detected in: 2019, 2020, 2019, and 2019, respectively. CPAP use in W was greater than S (p< 0.02). All other procedure comparisons had p-values>0.05. Conclusions: RSV and INF increased in all regions during pre-COVID. RSV and INF decreased in all regions during COVID. INF increased in all the regions towards the end of pandemic. RSV increased in MW and S near the end of the pandemic. Differences in use of CPAP for RSV were found between W and S.