More than 40% of U.S. adults have at least one underlying health condition that puts them at an increased risk of developing a severe case of Covid-19, according to a CDC Morbidity and Mortality Weekly Report published Friday.

When patients experience severe cases of Covid-19, the disease caused by the novel coronavirus, they can require hospitalization, intensive care, and mechanical ventilation, according to the University of Minnesota's Center for Infectious Disease Research and Policy.

Report details

For the report, CDC researchers sought to determine the prevalence of five health conditions known to put patients at a higher risk of developing a severe case of Covid-19:

• Chronic kidney disease (CKD);
• Chronic obstructive pulmonary disease (COPD);
• Diabetes;
• Heart disease; and
• Obesity, defined as having a body mass index (BMI) equal to or greater than 30.

According to the researchers, a prior analysis had found that, among Covid-19 patients with an underlying health condition, "hospitalizations were six times higher, ICU admissions [were] five times higher, and deaths [were] 12 times higher" when compared with Covid-19 patients without underlying medical conditions—although that research considered severe obesity, defined as having a BMI equal to or greater than 40, rather than general obesity.

To calculate the prevalence of each of the five health conditions under consideration for the new report, the researchers used statistical modeling based on self-reported data from the U.S. Census and the 2018 Behavioral Risk Factor Surveillance System, which is a telephone survey of 500,000 U.S. adults from every county in the country.

Findings

Overall, the researchers estimated that the median prevalence of any of the five health conditions in the United States was 40.7%. According to the researchers, the national weighted prevalence of:

• Obesity was 30.9%;
• Diabetes was 11.4%;
• COPD was 6.9%;
• Heart disease was 6.8%; and
• CKD was 3.1%.

When assessed by county, the median estimated county prevalence of any of the underlying conditions was 47.2%. When broken down by condition, the median estimated county prevalence of:

• Obesity was 35.4%;
• Diabetes was 12.8%;
• COPD was 8.9%;
• Heart disease was 8.6%; and
• CKD was 3.4%.

However, the researchers found significant disparities in the rates of CKD, CPOD, diabetes, heart disease, and obesity from county to county. For instance, the researchers found as few as one in four people had at least one of those conditions in some counties, but as many as two in three people had such conditions in other counties.

Overall, although the estimated number of people with one of the conditions was greater in population-dense, urban areas—ranging overall from 4,300 in a rural area to 301,744 in an urban area—the prevalence of the conditions tended to be greater in rural areas. According to the researchers, counties in states across Appalachia and the Southeast—including Alabama, Arkansas, Kentucky, Louisiana, Michigan, Mississippi, Oklahoma, South Dakota, Tennessee, Texas, and West Virginia—had the highest rates of any of the five health conditions.

Comments

The researchers said CDC's county-level data can help local health officials determine how to best respond to America's coronavirus epidemic.

"The findings can help local decision-makers identify areas at higher risk for severe Covid-19 illness in their jurisdictions and guide resource allocation and implementation of community mitigation strategies," they wrote. "These findings also emphasize the importance of prevention efforts to reduce the prevalence of these underlying medical conditions and their risk factors such as smoking, unhealthy diet, and lack of physical activity."

Dan Culver, a pulmonary and critical care physician at the Cleveland Clinic, said the data "will allow for more effective messaging about social distancing and other public health measures."

Culver added that the data also can help officials decide how to allocate supplies and medications. "Targeting the more vulnerable populations will be easier if we understand where they live," he said (Edwards, NBC News, 7/23; Van Beusekom, CIDRAP News, 7/23).