COVID-19 Mortality at the Intersection of Comorbidities and Age, Sex, Race Demographics

New research shows COVID-19 mortality risk to be more nuanced than previous studies.


Rather than simply examining linkages between age and COVID-19 mortality or preexisting condition and COVID-19 mortality, the study, published in the Journal of Infectious Diseases and Epidemiology, sought to examine how comorbidities and demographic factors (age, sex, and race) combine to affect COVID-19 mortality.

The study acknowledged previous research on the intersections between comorbidities, demographics, and COVID-19 mortality; specifically, several studies found that older, male patients with diabetes or hypertension are at higher risk for mortality upon contracting COVID-19.

However, this study looked to supplement these findings: “Prior observations have been reported for large groups but these may not be applied to certain patient subsets. It is essential, in light of the sustained high number of COVID-19 cases and deaths throughout the United States, that we identify subsets of the population at high risk for COVID-19 mortality.” 

The researchers looked to fill a gap in the literature by analyzing the disparities in mortality risk within various demographic groups, paying special attention to the potential interaction effects of comorbidities.

The study included 8324 adults who self-presented to the NYU Langone Health Care System in spring of 2020 and were diagnosed with COVID-19, 918 (11%) of whom eventually died from the virus. All patients included in the study were both symptomatic for COVID-19 and had a positive SARS-CoV-2 PCR test.

Because of previously observed differences in COVID-19 outcomes across sex, age, and race, the researchers chose to focus on these demographics. To determine whether the relationship between comorbidities and mortality differs across demographic subgroups, the researchers assessed for potential demographic modification effects. They stratified the relationship between comorbidities and mortality by demographic subgroup, assessing the importance of each interaction effect. The researchers performed univariate and multivariate analyses using SAS 9.4.

Univariate analysis showed a clear linkage between demographics and comorbidities on mortality rates. Of the 918 patients who died, 64% were male and 85% were 60 years of age or older. Forty-nine percent were white, 11% were Black, and 9% were Asian. 88% of the 34 preexisting comorbidities (30) were associated with increased risk of mortality, the highest being cardiac arrhythmia, myocardial infarction, coagulopathy, fluid or electrolyte disorders, hypertension, and neurological disorders.

Significant trends between demographic group and comorbidity included sex and depression, race and anemia, race and solid tumor without metastasis, age and cardiac arrhythmia, age and neurological disorders, age and paralysis, and age and pulmonary disorders. In all of these pairings, there was a higher risk of mortality.

The most notable results were that females with depression had a higher mortality rate than males with depression, and younger patients with preexisting cardiac arrhythmia, neurological disorders, paralysis, or pulmonary disorders had a higher risk of mortality than their older counterparts. Finally, the study found white patients with anemia and Black patients with solid tumors without metastasis had a higher rate of mortality than other racial groups with these comorbidities.

This research complicates previous assumptions of who is most at risk for severe or fatal COVID-19. “Our analysis highlights the importance of certain comorbidities and their effect on the risk of mortality for certain demographic groups generally considered ‘low risk,’ such as females and young people," the investigators wrote.

The findings were in line with related studies, but it expanded on previous research by including a more extensive list of comorbidities.

The investigators delved into the previously unexamined intersections between demographics and comorbidities, and they believe their findings warrant further study.