Who Was Hospitalized With COVID-19 in Atlanta, Spring 2020

This page summarizes a CDC report written with the Georgia Department of Public Health and Emory University, first posted June 17, 2020, about patients seen in March and April 2020, early in the pandemic.

By June 15, 2020, the United States had reported about 2 million COVID-19 cases and 115,000 deaths. Reports already showed that hospitalized patients were disproportionately older, male and black, and often had conditions such as diabetes, hypertension, obesity, cardiovascular disease, chronic kidney disease or chronic respiratory disease. Less was known about which factors actually raised the risk of being hospitalized.

The study

Investigators reviewed medical records of adults with laboratory-confirmed COVID-19 at six hospitals and their outpatient clinics, all part of one academic health system in metropolitan Atlanta:

• 220 hospitalized patients, taken in sequence from hospital lists for March 1–30, 2020 (including observation stays and deaths in an emergency department);
• 311 nonhospitalized patients, everyone seen in outpatient clinics or an emergency department and not admitted, March 1–April 7.

During that period a telephone triage line sent people with signs of severe illness, such as severe shortness of breath, confusion or coughing up blood, to an emergency department. Outpatient testing was limited and prioritized for health care workers and people at higher risk, such as those 65 or older or with certain underlying conditions.

The team compared the groups with logistic regression, using Firth's correction for small numbers. Because race was missing for 23% of nonhospitalized patients, they reran the analysis counting everyone with missing race first as black and then as another race.

Who was hospitalized

Compared with nonhospitalized patients, hospitalized patients were older (median age 61), and more often male (52%) and black (79%). They more often had obesity, a smoking history, hypertension, diabetes and chronic kidney disease. Among those whose occupation was recorded, 54% of nonhospitalized patients were health care workers, against 4% of hospitalized ones.

Fever and cough were common in both groups. Shortness of breath was more common among hospitalized patients; chills, headache, loss of smell or taste, and sore throat among those not hospitalized.

Independently linked to hospitalization, after adjusting for the other factors:

Reclassifying missing race did not appreciably change any result. Hypertension was no longer linked to hospitalization once other conditions were accounted for, suggesting that other conditions or factors that travel with hypertension may explain its high prevalence among hospitalized patients.

Interpreting the findings

• Diabetes had the strongest link of any underlying condition; it had been tied to more severe illness in COVID-19 and in Middle East respiratory syndrome. Obesity had also been reported as overrepresented among hospitalized patients.
• Race. Racial and ethnic minority groups face higher risk of severe COVID-19 partly because diabetes, cardiovascular disease and other conditions are more common among them. Social determinants such as housing, economic stability and work also play a part; black workers in the United States are more likely to be frontline or essential workers, raising their chance of infection on the job.
• Here, black race stayed linked to hospitalization even after accounting for diagnosed conditions, so conditions alone may not explain the higher rate. Black patients may have been more severely ill, or less likely to be identified as outpatients because of differences in access to or use of care, or other factors, including possible bias. Earlier studies had found race was not linked to death among those already hospitalized. More research was needed.

At the time, the report urged protection from infection for those at highest risk, including staying home, social distancing, and awareness and management of underlying conditions; cloth face coverings to protect others; and attention to the barriers that make such measures hard to follow.

Limitations

• People with mild illness may have gone elsewhere or not sought care, so hospitalization may reflect care-seeking and other differences as well as severity.
• Prioritized testing may have overrepresented older and sicker people among outpatients (underestimating the odds ratios), while health care workers among outpatients, if younger or healthier, could inflate them.
• Outpatient visits did not always include a full medical history.
• Age could only be studied in broad groups.
• Race, body mass index and smoking were missing for many nonhospitalized patients, and numbers were too small to look at other races or at ethnicity.

Sources

• Killerby ME, Link-Gelles R, Haight SC, et al. "Characteristics Associated with Hospitalization Among Patients with COVID-19 — Metropolitan Atlanta, Georgia, March–April 2020." MMWR 69(25). https://www.cdc.gov/mmwr/volumes/69/wr/mm6925e1.htm
• The report's figures are not reproduced, because it was prepared jointly with the Georgia Department of Public Health and Emory University.