People who recovered from a severe case of COVID-19 may have more to worry about: New research finds that patients hospitalized with COVID are 2.5 times more likely to die within the year than people who never contracted the coronavirus.
They also are nearly twice as likely to die as people who had a mild case of COVID, researchers say.
The risk of death is even higher for hospitalized COVID patients who are younger than 65 — more than three times that of the COVID-free and nearly three times that of mild COVID sufferers.
"If you think about it, this is a complication of COVID that people haven't looked at, but it's an extreme complication of COVID — that you're more likely to die after you get better," said lead researcher Arch Mainous, vice chair for research at the University of Florida Department of Community Health and Family Medicine.
Worryingly, only 1 in 5 people in the study who'd been hospitalized with COVID died of a health problem associated with the disease, he added.
"We find that only 20% of those deaths come from respiratory or cardiovascular diagnoses. That means people are dying of all kinds of things," Mainous said. "That's what makes it even more disturbing. Your risk of death is greatly increased, and you're going to die of stuff that people aren't ever going to link back to COVID."
Mainous and his colleagues already had found that people hospitalized with COVID were more than twice as likely to land back in the hospital within six months, compared with those who never got sick or had mild COVID.
"Then we said, let's take this to another level. Let's look at what happens to people in terms of mortality," Mainous said. "You can't get a harder outcome than that. Does this actually really increase your risk of death?"
The research team analyzed health records for more than 13,600 patients treated by University of Florida Health since January 2020, including 178 with severe COVID and 246 with mild or moderate COVID. The rest had tested COVID-free at some point.
The researchers started tracking the folks with severe COVID following their release from the hospital.
It turned out that patients hospitalized for COVID were 2.5 times more likely to die than infection-free folks and 1.8 times more than people with mild COVID, according to results published Dec. 1 in Frontiers in Medicine.
The news was worse for people younger than 65, who were 3.3 times as likely to die as COVID-free people and 2.8 times more than those with mild COVID.
Most people who died within a year of their COVID hospitalization died of causes unrelated to the heart or lungs, the organs most hard-hit by the coronavirus, Mainous noted.
"A lot of people have been dying post-COVID, and yet nobody's acknowledging it because they're not ending up in the hospital dying of COVID," Mainous said.
However, people hospitalized with severe COVID were 4.5 times more likely to die of respiratory ailments in the months following their recovery compared to people never infected, and three times more likely to die from heart problems, the researchers found.
It's not surprising that people hospitalized with COVID are more vulnerable in the months that follow, said Dr. Amesh Adalja, a senior scholar with the Johns Hopkins Center for Health Security in Baltimore.
"Any type of critical illness, especially from an infection, can have a cascading impact on health after the acute infectious process subsides," said Adalja, who wasn't part of the study. "The inflammatory response set off can cause wide-ranging damage in multiple organ systems."
COVID is known to do damage to virtually all the body's organs, including the brain and kidneys, Mainous said.
"You can see inflammation in all kinds of places. You can see it in the heart and lungs, you can see it in the kidneys," Mainous said of a severe COVID infection.
"The physiological insult, the trauma of being hospitalized with COVID, has such a detrimental impact on your body that then your body doesn't really recover very well," he continued. "You think you've recovered, you're out of the hospital, but then it leads to this very massive mortality risk."
These findings present a strong argument for getting the COVID vaccine, since it's the only known method of limiting the severity of infection, Mainous said.
"Masking and social distancing decreases your likelihood of acquiring COVID, but it doesn't affect the severity of your episode," Mainous said. "The only thing we know right now that affects your severity is vaccination. It's effective at decreasing your likelihood of being hospitalized with COVID or dying in the hospital."