Since the first case of coronavirus disease 2019 (COVID-19) was confirmed in the United States in January 2020, more than 12 million US residents have become ill, and more than 250 000 have died.1,2 The pandemic has affected the lives of all US residents, disrupted business operations, and overwhelmed hospitals. Despite its tremendous impact, there is a dearth of research on the epidemiology and clinical outcomes of patients with COVID-19 in the United States. Earlier literature has mainly focused on epidemiologic insights from China and the European Union,3-7 with difficulty extrapolating these findings to the US patient population due to different demographic, socioeconomic, and clinical characteristics as well as different health care delivery systems that affect utilization patterns.
To date, most studies from the United States use either surveillance data with minimal clinical information or data from single health care facilities.8-10 A study of 5700 patients with confirmed COVID-19 who were hospitalized in a large New York City health system during March 2020 showed that hypertension, obesity, and diabetes were the most common comorbidities; 14.2% of patients with COVID-19 required care in the intensive care unit (ICU); 12.2% of patients received invasive mechanical ventilation; and 21.0% of patients died.11 However, the overall treatment patterns and risk factors associated with in-hospital mortality among patients treated in hospitals across the United States remain largely unknown.
Using data from 592 hospitals included in the largest hospital discharge database in the United States, the Premier Healthcare Database (PHD), this study aimed to examine the epidemiology, clinical outcomes, and treatment patterns of patients with COVID-19 who were discharged between April 1 and May 31, 2020. It also aimed to identify potential risk factors associated with in-hospital mortality