097 - ED visits for acute respiratory illness: epidemiologic changes pre- to post-COVID-19

Publication Number: 97.4642

Mamata kene, The Permanente Medical Group, Fremont, CA, United States; Madeline Somers, Kaiser Permanente Division of Research, Pleasanton, CA, United States; Dustin Ballard, UC Davis, Kaiser Permanente, San Rafael, CA, United States; Adina Rauchwerger, Kaiser Permanente, Pleasanton, CA, United States; Daniel D. DiLena, Kaiser Permanente Division of Research, San Francisco, CA, United States; Dana Sax, Kaiser Permanente - Oakland Medical Center, Oakland, CA, United States; Mary Reed, Kaiser Permanente Division of Research, Kaiser Permanente Bernard J. Tyson School of Medicine, Pleasanton, CA, United States; Tara L. Greenhow, kaiser permanente - san francisco medical center, San Francisco, CA, United States

Background: The COVID-19 pandemic changed the epidemiology of respiratory viral infections, especially among children, with repercussions for emergency department (ED) care. Population-level immunity changes and altered patterns of viral predominance may have shifted the epidemiology and future surges of pediatric respiratory illnesses.

Objective: We thus evaluated ED visits for acute respiratory illness among children in a large, integrated healthcare delivery system to describe illness and patient characteristics in the years before, during and after the pandemic peak.

Design/Methods: We conducted a cross-sectional study of ED visits among patients aged 0-17 years to the 21 EDs of Kaiser Permanente Northern California (KPNC), from January 1, 2018-December 31, 2019 (pre-pandemic), January 1, 2020-December 31, 2021 (pandemic), and January 1, 2022-March 31, 2024 (vaccines for children >5 yrs more widely available). We electronically extracted eligible ED visits with acute respiratory infection diagnoses and a range of sociodemographic, medical comorbidity and utilization characteristics.

Results: We observed 151,983 pediatric ED visits with eligible respiratory infection diagnoses, 49,912 visits pre-pandemic, 27,109 visits pandemic and 74,962 visits late-pandemic. Sex, race/ethnicity, and tobacco exposure were comparable over time, but the proportion of visits by patients who were under-immunized trended upward over time (Table 1). Seasonal fluctuations in ED visits pre-pandemic flattened in the early months of the pandemic, before monthly variation resumed, and visits increased in the last observation period (Figure 1). Upper respiratory infection, asthma and cough were the top three diagnoses across all periods.

Conclusion(s): In this cross-sectional study of acute respiratory illness-related ED visits in an integrated healthcare system, we noted an abrupt change to the seasonal ebbs and flows of visits during the start of the pandemic, a sharp rise in visit volume later in the pandemic, and subsequent return to seasonal variation. Patient characteristics were comparable across the study periods as were the three most common visit diagnoses (upper respiratory infection, asthma and cough). Surge planning and mitigation strategies may be aided by this understanding of the current state of respiratory infection-related ED visits, especially as COVID-19 is now endemic and typical respiratory pathogens have resurfaced

Figure 1: Monthly ED visits for acute respiratory illness, Jan 1, 2018-March 31, 2024, Age 0-17 yrs
PAS Kene Fig 1 Resp dz.jpegBlue: All ED visits
Green: COVID-19
Purple: Acute respiratory illness

Table 1: Patient and visit characteristics, ED visits for acute respiratory illness, January 1, 2018-March 31 2024
PAS Kene Table 1, Resp dz_.jpeg

Figure 1: Monthly ED visits for acute respiratory illness, Jan 1, 2018-March 31, 2024, Age 0-17 yrs
PAS Kene Fig 1 Resp dz.jpegBlue: All ED visits
Green: COVID-19
Purple: Acute respiratory illness

Table 1: Patient and visit characteristics, ED visits for acute respiratory illness, January 1, 2018-March 31 2024
PAS Kene Table 1, Resp dz_.jpeg