CHICAGO, Dec. 16 (Xinhua) -- New research into federal data by researchers at Washington University School of Medicine in St. Louis reveals that among hospitalized patients, COVID-19 was associated with an increased need for ventilators, more admissions into intensive care units (ICUs), longer hospital stays and nearly five times the risk of death than faced by those with the flu.

For the study, the researchers analyzed de-identified medical records in a database maintained by the U.S. Department of Veterans Affairs, and examined information involving 3,641 patients hospitalized in the United States with COVID-19 at some point from Feb. 1 through June 17, as well as 12,676 patients hospitalized with the flu at some point from Jan. 1, 2017, through Dec. 31, 2019. The average age of patients with either COVID-19 or the flu was 69.

Among patients hospitalized for either COVID-19 or the flu, those infected with the novel coronavirus were nearly five times more likely to die than those with influenza. Of the 12,676 patients with flu, 674, or 5.3 percent, died; and of 3,641 patients with COVID-19, 676, or 18.5 percent, died.

On average, the COVID-19 patients were four times more likely to require breathing machines and almost 2.5 times more likely to be treated in the ICU. Also, COVID-19 patients were more likely to be hospitalized longer, an average of three extra days.

One of the biggest surprises in the study was the finding of a higher risk of developing diabetes among COVID-19 patients than flu patients: nine more cases per 100 people.

The data analysis showed that the COVID-19 patients most at risk for death were those 75 years old and older who also had chronic kidney disease or dementia; and African Americans who were considered medically obese, or who had diabetes or kidney disease.

The researchers also found that, when compared with the flu, COVID-19 was associated with a higher risk of acute kidney damage and severe sepsis shock, both at six more cases on average per 100 hospitalized patients.

Compared with flu patients, people with COVID-19 also required more medications to treat severely low blood pressure, a condition that can lead to organ damage and death, 11.5 more people per 100 people.

"We can call COVID-19 a respiratory virus all we want, but if you look at the associated clinical consequences, it can cause significant damage to the brain, liver, heart, kidneys and blood-clotting systems," said senior author Ziyad Al-Aly, an assistant professor of medicine at Washington University. "It's a destructive virus."

"It's quite possible that a year or five years from now there could be COVID-19 complications that we haven't considered. Already, we're aware of the long-haulers, or people who get COVID-19 but never fully recover. They might feel an ongoing malaise or extreme fatigue or experience appetite changes."

The findings were published Tuesday online in the journal The BMJ.