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More than 100 million Americans are at higher risk for serious illness if they contract COVID-19, according to a new Kaiser Family Foundation (KFF) report.

Wyatt Koma, BS, a researcher with the KFF Program on Medicare Policy, and colleagues calculate that 105.5 million people in the US are at high risk of serious illness if infected, which includes 29.2 million adults under the age of 60, because of an underlying medical condition, and 76.3 million adults at least 60 and older.

One group particularly at risk is the 1.3 million people living in nursing homes in the US, the authors point out in the report released March 13.

Koma told Medscape Medical News, "I hope this analysis really helps the public understand the potential reach and impact of coronavirus."

He added, "With 4 out of every 10 people in the US at higher risk of serious illness if they are infected with coronavirus, these estimates confirm the need to take unprecedented efforts to minimize the spread."

Overall, Most Infected Will Recover Quickly

According to the World Health Organization, most people who become infected won't develop symptoms or will recover quickly without needing treatment. But 41% of US adults (105.5 million out of 258 million in 2018) fall into the groups at higher risk of serious illness if they are infected by the novel coronavirus.

Koma and colleagues used data from the nationally representative 2018 Behavioral Risk Factor Surveillance System (BRFSS) and calculated the numbers at risk by state and nationwide.

The researchers defined "high-risk," using the latest information from the Centers for Disease Control and Prevention (CDC) as adults ages 60 and older and younger adults between ages 18 and 59 with cancer, heart disease, chronic obstructive pulmonary disease (COPD), or diabetes. The authors acknowledged they could not factor in hypertension because that variable was not tracked by the survey.

According to the American Heart Association, about 1 in 3 US adults have high blood pressure.

"If we had included hypertension, it is likely the number of younger adults at higher risk of illness if they're infected with coronavirus would have increased," Koma said.

"Also, with this data source, we were unable to account for people living in institutional settings, such as nursing homes, assisted living facilities or prisons," he said. "Had we been able to incorporate the institutional population, the number of under-60 individuals at risk of serious illness, if infected, would have also been higher."

The risk by state, according to the KFF report, varies widely from 31% in Washington, DC, to 51% in West Virginia.

"In Washington State, California, and New York, some of the states hardest hit by COVID-19 thus far, the share of adults at high risk is 40%, 37% and 40%, respectively," the authors write.

Koma explained that West Virginia's risk is high mainly because of the larger share of the younger adult population who have a serious health condition. Conversely, Washington State has a relatively lower overall rate of adults at risk of serious illness if they get infected because there is a relatively smaller share of adults younger than age 60 at higher risk.

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