COVID-19 is at least 5 times deadlier than flu for hospitalized patients

A patient in the ICU.
(Image credit: Shutterstock)

COVID-19 truly is more deadly than the flu — patients hospitalized with COVID-19 were five times more likely to die than those with the flu, according to a new study from the Centers for Disease Control and Prevention (CDC). 

What's more, the study found COVID-19 patients were at higher risk for 17 additional, serious health complications, including pneumonia, respiratory failure and blood clots, compared with flu patients. However, because the study only looked at hospitalized patients, it can't directly compare overall mortality rates between the two diseases.

Ever since the new coronavirus was discovered in early January, people have compared it with the flu. As recently as this month, President Donald Trump drew criticism when he posted on Twitter that COVID-19 is "far less lethal" than the flu; the post was quickly flagged for spreading misinformation about COVID-19, according to NBC News.

Mounting evidence shows that COVID-19 is more severe than flu.

In the new study, published Tuesday (Oct. 20) in the CDC journal Morbidity and Mortality Weekly Report, the researchers compared complications from COVID-19 and flu using data from Veterans Health Administration hospitals nationwide. The authors analyzed information from nearly 4,000 patients — with an average age of 70 — hospitalized with COVID-19 from March 1 through May 31 2020, and more than 5,400 patients — average age of 69 — hospitalized with flu from Oct. 1, 2018 through Feb. 1, 2020.

Overall, 21% of COVID-19 patients died while hospitalized, compared with only 4% of flu patients — a more than five-fold difference. In addition, COVID-19 patients had more than double the risk of being admitted to the intensive care unit (ICU), and their length of stay was nearly three times as long. But these numbers take into account only those who were hospitalized. 

But evidence suggests a greater fraction of people who are infected with COVID-19 will need hospitalization than those who contract the flu, so COVID-19 is likelier more than five times deadlier than flu in the population overall. According to estimates from the CDC, about 1% of people who got sick with the flu were hospitalized during the 2019-2020 season. In contrast, up to 20% of COVID-19 patients may require hospitalization, according to early estimates from the World Health Organization.   

Related: 20 of the worst epidemics and pandemics in history  

COVID-19 patients were also at higher risk for dozens of complications. For example, compared with flu patients, COVID-19 patients were nearly 19 times more likely to develop acute respiratory distress syndrome (ARDS), a serious lung condition that causes low blood oxygen levels. COVID-19 patients were also more than twice as likely to develop  myocarditis (inflammation of the heart muscle), deep vein thrombosis (a blood clot typically in the legs), pulmonary embolism (a blood clot in the lungs) and intracranial hemorrhage (a brain bleed), than flu patients.

The study also found that minority groups, including Black and Hispanic patients, were at higher risk for many complications, such as respiratory, neurologic, and kidney complications, compared with white patients, even after the researchers took into account patients' age and underlying medical conditions. The finding adds to a growing body of evidence showing that minority groups have been hit hard by COVID-19, which may be due to "social, environmental, economic and structural inequities," the report said.

Overall, the findings "illustrate the increased risk for complications involving multiple organ systems among patients with COVID-19 compared with those with influenza," the authors wrote. "Clinicians should be vigilant for symptoms and signs of a spectrum of complications among hospitalized patients with COVID-19 so that interventions can be instituted to improve outcomes and reduce long-term disability."

Originally published on Live Science.  

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.

  • MMMark
    "Hospitalized" is the keyword. Patients delirious with fever in a disease centre isolated from friends and family surrounded by frightened ghouls wearing bin bags and goggles. I had it, starting suddenly with pain in the stomach, scrubbing brush in the lungs, pain in the head, vomiting and a centimetre of sweat all over. I had to bear this for several days. I stayed in bed.
  • OldeSalty
    That's cute. So you think your single case of anecdotal evidence is enough to ignore data and science? You are willfully ignorant if you see the data and still ignore it. Just because you had a mild case, yes I said mild based on your description, doesn't mean that is the case for many people. I also know people that got it and have fewer symptoms than you. I also know some that have had severe cases and even ones that have died. A friend of mine died from it recently. But that is also anecdotal evidence... so I tend to ignore in in place of the data... as you should consider doing the next time you want to voice an opinion on facts and data.
  • Sam Minnerve
    Very hard to understand how 20% of victims can need hospitalising. There are enough figures available now to challenge this.
    I’ve been looking at the French data which is well reported and about 10% of the victims since the start of the pandemic have been hospitalised.
    But that’s of the people who have been tested positive and they are by definition the people the most sick with the disease.
    There are perhaps 4-5 times more than that who have had the disease without being tested because the symptoms were mild, and maybe double that who were symptomless (It’s reckoned about 50% of people infected are symptomless, especially young people). Testing hasn't always been freely available either.
    But even that is probably high for the current situation.
    At the beginning of the crisis, people were much more likely to be sent to hospital than they are now. There are doctors everywhere successfully treating patients at home and patients in nursing homes are no longer being sent to hospital except in the most extreme cases.
    There have been 178358 French infections reported in the last week and 3991 hospital admissions suggesting a current rate of about 2%
    Looking further at the excellent French reporting, they have almost exactly the same infection rate in the over 90s as they do in the 20-29s-185 per 100,000 and 190 per 100,000 so it can’t be said it’s only the young getting infected at the moment which would otherwise explain why there are so few hospitalisations.
    Furthermore, figures for the over 60s and over 70s are roughly 120 per 100,000 But there were only 156 deaths in nursing homes in the last week whereas over a quarter of all deaths up to now have been in those homes- mostly at the beginning of the epidemic
    Your study quoted is looking at rates in March to May when people were almost automatically slammed into hospital on a ventilator and it was the wrong thing to do.
    Even proning has been shown to have greatly reduce the death rate as have other basic facts like the nursing staff being better and quicker at noticing the signs of collapse and the successful administering of steroids and anti-coagulants.
    We have to accept something isn’t the same as 6 months ago from all the recent figures and we need to base assumptions on what we are seeing now we have more experence and knowledge and frankly, things aren’t looking anything like as bad as that at the moment.
    What will make a difference of course is when the IC units are once again at full capacity.
    When they have to turn people away they will once again die on the floor as they did in March and April and we will see these figures rise rapidly.
    That is why it is so vital we have to make these sacrifices now to keep the infection rate treatable.
  • StuN
    Whoa, whoa, whoa. The average age of the two cohorts WAS 70 AND 69?? How about placing that information in the headline?