1 in 6 people bedridden with flu for at least a day during typical season, study finds

May 12 (UPI) -- About one in six people in the United States is bedridden for at least one day during a typical flu season, an analysis published Thursday found.

Based on data collected from a commercially available "step counter" worn by more than 15,000 adult participants, those who contracted the flu or a similar respiratory viral illness lost, on average, more than 4,400 steps over a 10-day period, data published Thursday by JAMA Network Open showed.

If accurate, that means that, cumulatively, the entire population of the United States would lose more than 255 billion steps during a typical flu season, the researchers said.

This figure equates to about 15% of the people across the country being bedridden, or not moving, for at least one day. they said.

Just over 60% of this decline in mobility due to the flu is seen in people who do not seek medical care for their illness, according to the researchers.

"These findings suggest that when we consider the whole population, most of the total burden of the flu actually lies in the majority of people who do not seek medical attention," study co-author Aziz Mezlini told UPI in an email.

"These people are typically missed when we rely on data from health institutions," said Mezlini, a senior machine learning scientist with San Mateo, Calif.-based research firm Evidation Health.

In a typical flu season, about 40 million people in the United States are sickened with the virus, although only a fraction of these cases are confirmed with lab tests, according to the Centers for Disease Control and Prevention.

About 10% of those who get the flu, mostly the elderly, are hospitalized as a result, the agency says.

Flu cases have dropped significantly across the country since the start of the COVID-19 pandemic in March 2020, as mask-wearing and social distancing, among other measures, helps prevent the spread of both viruses, the CDC says.

For this study, the Evidation Health researchers outfitted 15,122 adult participants with a commercially available step-counter, which counts the steps a person takes during the day, for the 2018-19 flu season, or from October 2018 through June 2019.

Of the study participants, 2836, or 19%, sought medical attention for the flu and less than 1% were hospitalized, the data showed.

The study shows "the value of wearable data in providing an objective measure of disease burden on individuals and populations," Mezlini said.

"Here we showed how to use that data to estimate the burden of flu, but this can also be used for other diseases such as COVID," he said.