In the United States, emergency rooms located in hospitals have consistently accounted for a significant portion of total hospital use. There were an estimated 150 million hospital-based emergency department (ED) visits in the United States in 2019, up from 137 million in 2015 and 90 million each in 1993, 2000, and 2019. For a study, researchers examined hospital emergency department visit registration data from before and during the COVID-19 pandemic to characterize the effect on hospital ED use and to determine the long-term effects of COVID and other variables on the use of hospital-based emergency services.

In order to describe the effect of the COVID-19 pandemic on EDs and evaluate long-term implications, they analyzed real-time hospital ED visit registration data from a large sample of US hospitals to document changes in ED visits from January 2020 through March 2022 relative to 2019 (pre-COVID baseline).

The statistics indicated a sharp initial decline in ED visits in the first half of 2020 (relative to levels in 2019), a rise in 2021, but never a return to pre-pandemic levels. Since 2019, there has been a general drop in the number of ED visits throughout the study states: in 2020, the decline was -18%; in 2021, -10%, and the first quarter of 2022, -12% less than in 2019.

The reported decline in demand for hospital-based emergency care had a wide variety of possible long-term ramifications for emergency doctors, hospitals, health insurance, and patients.