UW Health: Hospital conditions are driving factors behind risk for increased death rate among COVID patients in ICU

UW Health University Hospital entrance

MADISON, Wis. — Researchers with the UW School of Medicine and Public Health say physical health is only one factor to consider when analyzing a hospital’s likelihood to have increased intensive care unit mortality rates for patients with COVID-19.

According to research published in the American Journal of Respiratory and Critical Care Medicine, UW researchers used hospital data from around the country to determine the other factors that lead to increased mortality rates within 28 days of a patient’s admission. They found that the socioeconomic status of a hospital’s patient population and hospital strain were driving factors behind some hospitals’ higher 28-day ICU mortality rates.

Dr. Matthew Churpek — associate professor of medicine at the UW School of Medicine and Public Health and pulmonary and critical care physician at UW Health — said researchers dove into the data to understand the impacts that hospital systems and patient health have on a patient’s risk of death in hopes that could lead to improved care.

“For an individual patient critically ill with COVID-19, less than half of their mortality risk can be attributed to their physiology,” Churpek said. “This highlights the importance of other factors, such as hospital strain, co-morbidities and socioeconomic status.”

Churpek and his colleagues looked at a dataset of 4,019 patients with COVID-19 who were admitted to ICUs at 70 hospitals nationwide between March 4 and June 29, 2020. According to that data, 1,537 of those patients, roughly 38%, died within 28 days of admission. The mortality rate for those patients varied drastically from 0% at the lowest-risk hospital to 82% at the highest-risk hospital.

Researchers then considered a variety of variables at the patient (severity of illness, demographics, history of smoking) and hospital (hospital strain and national scores for mortality, safety and effectiveness, among others) levels to determine which variables had the greatest impact on an individual’s risk of death.

“We found that the biggest determinants were severity of patient condition upon admission to the ICU, followed by the overall socioeconomic status of the population served by each hospital and level of hospital strain,” he said. “These findings suggest that COVID-19 may be exacerbating existing healthcare disparities in the United States.”

Churpek said researchers plan to study if the importance of socioeconomic status relates more to an individual’s status or to other yet-to-be-identified hospital characteristics.

“Ultimately, our hope is that by identifying the drivers of mortality variation, we can discover new ways to reduce it and improve outcomes for critically ill patients with COVID-19,” he said.