Racial, Ethnic Disparities in COVID-19 Testing and Outcomes

Senior patient using mask looking through window at hospital
Researchers conducted a study to determine the effect of patient characteristics and racial/ethnic disparities on outcomes of SARS-CoV-2 infection.

Poor COVID-19 outcomes were found to be disproportionately associated with at-risk populations including older adults, those with preexisting conditions, and those residing in densely populated communities, according to a retrospective cohort study published in JAMA Network Open. These findings also suggest that SARS-CoV-2 infection testing and prevention efforts should be increased among racially diverse communities.

Researchers analyzed data from groups of patients tested or treated for COVID-19 at the University of Michigan between March and April 2020 and compared them with a group of randomly selected untested individuals. Results were updated through July 2020. Variables for comparison included race/ethnicity, age, smoking status, alcohol use, comorbidities, and BMI. Investigators also analyzed residential-level socioeconomic characteristics using the 2010 Neighborhood Socioeconomic Disadvantage Index (NDI), which is the mean proportion of the population that is in poverty, unemployed, using public assistance income, and woman-headed families with children. They also included population density as a covariate in susceptibility models.

The researchers used logistic regression to assess the primary outcomes, which were undergoing testing for COVID-19, testing positive for or being diagnosed with COVID-19, hospitalization or admission to an intensive care unit (ICU) due to COVID-19, and COVID-19-related mortality.

Among a total of 5698 patients included in the study, the mean age was 47.4 (SD, 20.9) years, 38% were men, 65.6% were non-Hispanic White, and 18.6% were non-Hispanic Black. Of the 7168 patients in the comparison group, the mean age was 43.1 (SD, 24.1) years and 45.4% were men.

The researchers found that the odds of undergoing SARS-CoV-2 infection testing were increased among Black patients, those aged 35 to 50 years, those with an increased comorbidity burden, and those residing in densely populated areas. Similar results were observed among patients with certain risk factors including obesity, alcohol consumption, and those with a history of smoking.

Of 1139 patients diagnosed with COVID-19, 43.2% were White and 38.8% were Black. The test positivity rate was significantly increased among Black patients (41.8%) vs White patients (13.2%; P <.001). In addition, the researchers found that White patients with an autoimmune disease had an increased odds for testing positive for COVID-19 compared with Black patients with an autoimmune disease (odds ratio [OR], 3.15 vs 1.56, respectively; P for interaction =.006). Obesity was associated with an increased risk for testing positive for COVID-19 among Black patients vs White patients (OR, 1.37 vs 3.11; P for interaction=.02). In Black patients only, preexisting cancer was associated with an increased risk for testing positive for COVID-19 (OR, 1.82; 95% CI, 1.19-2.78; P =.005).

After adjustment for age, sex, comorbidity score, and socioeconomic status, the researchers found that the risk for hospitalization due to COVID-19 was increased among patients who were Black vs those who were White (OR, 1.72; 95% CI, 1.15-2.58; P =.009). In White patients only, overall comorbidity burden (OR, 1.30; 95% CI, 1.11-1.53; P =.001) and preexisting type 2 diabetes (OR, 2.59; 95% CI. 1.49-4.48; P <.001) were associated with an increased risk for hospitalization. A similar increased risk for hospitalization was observed among patients residing in densely populated areas (OR, 1.10; 95% CI, 1.01-1.19; P =.02).

The researchers performed a multivariable logistic regression analysis and found no statistically significant differences for ICU admission in terms of race or ethnicity; however, White patients with respiratory diseases had an increased risk for ICU admission vs Black patients (OR, 2.23 vs 0.51; P for interaction =.01), with a similar trend observed among those with any cancer who were White vs those who were Black (OR, 1.47 vs 0.53; P for interaction =.03).

Of the 7 comorbidities analyzed, type 2 diabetes (OR, <1.82; 95% CI, 1.25-2.64; P =.002) and kidney disease (OR, 2.87; 95% CI, 1.87-4.42; P <.001) were associated with the greatest increased risk for hospitalization. In addition, patients with kidney disease also had an increased risk for ICU admission (OR, 2.74; 95% CI, 1.76-4.26; P <.001). Of note, older age, male sex, and obesity were consistently associated with worse disease outcomes.

This study was limited by its inclusion of patients from the same hospital and those who were transferred from another hospital, and the differences between the comparator and control groups.

“Our results support targeted screening for [older] adults and those with type 2 diabetes and kidney disease,” the researchers noted. The researchers concluded that there is a need for “increased investments in testing and prevention efforts in lower-socioeconomic status, densely populated, and racially diverse communities.”

Disclosure: Some author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 


Gu T, Mack JA, Salvatore M, et al. Characteristics associated with racial/ethnic disparities in COVID-19 outcomes in an academic health care system. Published correction appears in JAMA Netw Open. August 2, 2021;4(8):e2126218]. JAMA Netw Open. Published online October 1, 2021. doi:10.1001/jamanetworkopen.2020.25197