First and Second Wave Dynamics of Emergency Department Utilization during the COVID-19 Pandemic: a retrospective study

Background Since the COVID-19 pandemic, there has been a decrease in emergency department(ED) utilization. Although this has been thoroughly characterized for the first wave(FW), studies during the second wave(SW) are limited. We examined the changes in ED utilization between the FW and SW, compared to 2019 reference periods. Methods We performed a retrospective analysis of ED utilization in 3 Dutch hospitals in 2020. The FW and SW (March-June and September–December, respectively) were compared to the reference periods in 2019. ED visits were labeled as (non-)COVID-suspected. Findings During the FW and SW ED visits decreased by 20.3% and 15.3%, respectively, when compared to reference periods in 2019. During both waves high urgency visits significantly increased with 3.1% and 2.1%, and admission rates (ARs) increased with 5.0% and 10.4%. Trauma related visits decreased by 5.2% and 3.4%. During the SW we observed less COVID-related visits compared to the FW (4,407 vs 3,102 patients). COVID-related visits were significantly more often in higher need of urgent care and ARs where at least 24.0% higher compared to non-COVID visits. Interpretation During both COVID-19 waves ED visits were significantly reduced, with the most distinct decline during the FW. ED patients were more often triaged as high urgent and the ARs were increased compared to the reference period in 2019, reflecting a high burden on ED resources. These findings indicate the need to gain more insight into motives of patients to delay or avoid emergency care during pandemics and prepare EDs for future pandemics. Funding None ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the medical ethical committee of Zuyderland Medical Center, Heerlen, the Netherlands (METCZ20210031). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present work are contained in the manuscript * ### Abbreviation AR : admission rate COVID-19 : coronavirus disease ED : emergency department FW : first wave GP : general practitioner IQR : interquartile Range MTS : Manchester Triage System PPE : personal protective equipment SARS-CoV-2 : severe acute respiratory syndrome coronavirus 2 SW : Second wave WHO : World Health Organization