Changes in Emergency Department Patient Volume and Acuity Associated with Early Stages of the COVID-19 Pandemic in a Unique Environment.

INTRODUCTION: Hospitals and emergency departments (EDs) faced profound uncertainty during the COVID-19 pandemic. Early concerns regarding demand far exceeding capacity were balanced by anecdotal reports of decreased patient visits, including those for specific high-acuity conditions. This study sought to identify changes in ED volume and acuity, within a specific managed care environment, associated with the onset of the pandemic.
METHODS: Data from patient visits to 2 San Diego, California, EDs-within an integrated health-care system-were extracted from the electronic health record. Daily patient visits, hospital admissions from the ED, Emergency Severity Index scores, and mode of arrival were compared between two 28-day periods, with the 28 days following a "stay at home" order issued by the governor of California and a control period of the same dates in 2019.
RESULTS: These EDs observed a significant decrease in daily visits (42% compared to the previous year) associated with the pandemic. An increased rate of hospital admissions (16.6%-21.6%) was suggestive of an overall increase in acuity; however, changes in the distribution of Emergency Severity Index scores were less pronounced. The overall number of admissions declined significantly. Although overall ambulance traffic decreased, the proportion of patients arriving by ambulance was unchanged.
CONCLUSION: Patient volume in 2 EDs dropped significantly in association with a statewide response to the COVID-19 pandemic. There was also a shift in acuity as measured by the proportion of patients admitted to the hospital, but overall admissions declined, suggesting sicker patients also did not seek care.