Change of utilization of emergency department in children after lifting mask mandates in a single center in Korea

Purpose We aimed to investigate changes in visiting patterns after the lifting of mask mandates in a single pediatric emergency medical center in Seoul, Korea. Methods This retrospective study was based on the data of patients’ (≤ 18 years) visits to the emergency department (ED) of the center from January 1, 2022 through June 30, 2023. Clinical characteristics, Korean Triage and Acuity Scale (KTAS) level, ED outcomes, and length of stay were compared between before (March 20-June 30, 2022) and after (March 20-June 30, 2023) the lifting of mask mandates. The comparisons were iterated in the patients with infectious disease. Results During the study period, a total of 18,654 children visited the ED. After the lifting of mask mandates, ED visits increased from 7,146 to 11,508 (61.0%; 95% confidence interval, 59.5-62.6; P < 0.001). The increase was more prominent in the age of 2-5 years (82.9%), infectious diseases (175.3%), KTAS level 3 (127.7%), and length of stay shorter than 3 hours (78.8%-92.6%). The number of patients per hour increased by 151.2% for 5 patients or more and over 3,000% for 10 or more. Median length of stay decreased (2.3 hours [interquartile range, 1.2-4.1] to 1.9 hours [1.1-3.5]; P < 0.001). The patients with infectious disease (n = 7,139) showed similar patterns of increase in the age of 2-5 years, KTAS level 3, and length of stay shorter than 3 hours, with an additional increase in the age of 6-18 years. Conclusion After the lifting of mask mandates, pediatric visits increased by 61%, with the highest increase in children with mild infectious diseases on weekends and at night, and the proportion of more than 10 visits per hour significantly increased. We need urgent and realistic support measures from health authorities.