A flu shot not only lowers the chance of getting the flu, it can also help protect you from a heart attack, especially if you are older. So why is it that fewer than half of all adults get them?

A close look at hospital records by researchers from the Texas Tech University Health Sciences Center School of Medicine found that hospitals are missing a golden opportunity to protect their patients' health by not giving them a flu shot when they visit. The review of over seven million medical records of people admitted to a hospital in 2014 showed that very few older adults received a flu vaccination during their hospital stay.

Patients 50 and over who got flu shots were 73 percent less likely to die during their hospital stay.

These were high-risk individuals — adults 50 years and older, people with chronic medical conditions, AIDS patients, people at nursing homes, obese people, American Indians and Alaskan natives.

A hospital stay should be a good time for a patient to get their flu shot. They're in the right place and surrounded by people qualified to administer the vaccine. But the vaccination rate of patients was low, and it was considerably lower for at-risk people.

Patients 50 or over received a flu shot less than two percent of the time. The rate was around 15 percent for all hospitalized patients. Similar disparities were seen for most other high-risk groups, with American Indians and Alaskan natives the exceptions.

“These groups should have the highest vaccination rates because they are the most at risk; however, our findings show the opposite — flu vaccinations are under-utilized,” said lead investigator, Roshni Mandania, a 2021 MD candidate at Texas Tech University Health Sciences Center School of Medicine, in a statement. “As health care providers, we must do everything we can to ensure our most vulnerable populations are protected against the flu and its serious complications.”

The study only recorded hospital flu shots, which wouldn't be needed if people had already gotten one from their doctor or from a drug store, so it may be hard to draw many conclusions from this research. It is also possible that patients may have been offered one but refused the vaccine.

With a general vaccination rate of under 50 percent, however, it is likely that there were substantially more patients in need of a flu vaccine than actually received one. “The results we found are staggering. It’s hard to ignore the positive effect the flu vaccine can have on serious cardiac complications,” Mandania said in a statement.

Although it can't be shown that the flu shot was responsible, patients 50 and over who did get one were 73 percent less likely to die during their hospital stay, a connection that certainly bears further investigation.

The study was presented at the virtual American Heart Association's Basic Cardiovascular Sciences 2020 Scientific Sessions on July 27, 2020. To find it, search for “flu vaccine.”