More than 3 million people in the United States have been infected with COVID-19 and more than 130,000 have died. More people have died of COVID-19 in the U.S. than in any other country, but few studies offer national data on the factors that may contribute to outcomes for critically ill patients. To address this gap, investigators from more than 65 sites across the country, led by a team from Brigham and Women's Hospital, conducted the Study of the Treatment and Outcomes in critically ill Patients with COVID-19 (STOP-COVID), a multicenter cohort examination of the demographics, comorbidities, organ dysfunction, treatment, and outcomes of patients with COVID-19 admitted to intensive care units. The team studied over 2,000 critically ill adults with COVID-19, and found that 35 percent of patients died in the 28 days after ICU admission. They also found that treatment and outcomes varied greatly between hospitals. Results of their work are published in JAMA Internal Medicine.