The coronavirus disease 2019 (COVID-19) pandemic has impacted various segments of the United States population disproportionately. From a racial and ethnic perspective, minorities like Black, Hispanic, and American Indian or Alaska Natives, have had unusually high numbers of COVID-19 cases, hospitalizations, and deaths. From a gender perspective, men have also been at a disproportionately high risk of COVID-19-related hospitalization and mortality.
There is limited research on U.S. population-level disparities in COVID-19 mortality outcomes across the intersection of race/ethnicity and sex due to the absence of publicly available data.
Researchers from the University of California Los Angeles (UCLA), and Harvard University attempted to bridge this gap by analyzing the first publicly available dataset from the National Center for Health Statistics (NCHS). To this end, this collaborative effort aimed to determine a possible demographic explanation of COVID-19 mortality on the basis of age, sex, and ethnicity.
Study: National Population-Level Disparities in COVID-19 Mortality Across the Intersection of Race/Ethnicity and Sex in the United States. Image Credit: Designifty / Shutterstock.com
Population demographics of COVID-19 in the United States
Previous research by Rushovich et al. calculated population-level disparities in COVID-19 mortality outcomes by race and sex jointly in the U.S.; however, these estimates were obtained from the limited dataset that was currently available from Michigan and Georgia.
In their work, the researchers found that males had higher COVID-19 mortality rates than females within all racial groups considered. Furthermore, the magnitudes of the sex disparity for different races/ethnicity categories varied substantially, thus illustrating the interactive nature of race and sex in their association with COVID-19 mortality outcomes.
About the study
The current study, which is available on the preprint server medRxiv*, accessed more comprehensive datasets from the NCHS to calculate COVID-19 death counts stratified by race/ethnicity, sex, and age for the year 2020. Additionally, the researchers were also interested in determining the mortality rates for each race/ethnicity-sex-age stratum and age-adjusted mortality rates for each race/ethnicity-sex stratum, as well as identifying any existing disparities in terms of mortality rate ratios and rate differences.
Herein, the researchers examined a dataset from the NCHS that was publicly released on April 15, 2021. This dataset provided a detailed account of COVID-19 death counts (ICD-10 code U07.1 (21) as an underlying or multiple causes of death and was stratified by race/ethnicity, sex, and age for 2020. This dataset also included counts of different comorbidities like diabetes mellitus, Alzheimer’s disease, influenza, and pneumonia of those deaths due to COVID-19; however, these factors were not included in the analysis.
Data was divided into distinct categories: male and female in sex, and non-Hispanic White (NH White), non-Hispanic Black (NH Black), Hispanic, non-Hispanic Asian (NH Asian), non-Hispanic American Indian or Alaska Native (NH AIAN), non-Hispanic Native Hawaiian or Other Pacific Islander (NH NHOPI), and Unknown, in race/ethnicity.
In the current study, the researchers observed that males had higher COVID-19 mortality rates than females within almost all race/ethnicity-age strata. Males were also found to have higher age-adjusted mortality rates than females within each racial/ethnic group considered.
The age-adjusted mortality rate for males was over 60% higher as compared to that of females among NH Asian/PI’s, and over 80% higher among Hispanics. Overall, the male-female differences in age-adjusted mortality rates are highest among and NH Blacks.
To this end, age-adjusted mortality rates for NH Blacks were over twice that of NH Whites, whereas age-adjusted mortality rates for Hispanics are over 2.5 times that of NH Whites. Comparatively, among females, age-adjusted mortality rates for NH Blacks and Hispanics were over 75% higher than that for NH Whites.
Among males, the COVID-19 age-adjusted mortality rate is lowest among NH Whites, followed by NH Asian/PI’s, while that for Hispanics is notably greater than that of NH Blacks. Among females, however, the order is switched: the COVID-19 age-adjusted mortality rate is lowest among NH Asian/PIs, followed by NH Whites, while that between NH Blacks and Hispanics are indistinguishable
Overall age-adjusted mortality rates for NH AIANs were over twice that of NH Whites among both males and females. Among females, the age-adjusted mortality rate is highest among NH AIAN, but for males, the age-adjusted mortality rate for NH AIANs is higher than those of NH Whites, NH Blacks, and NH Asian/PIs but is indistinguishable from that of Hispanics
The current study empirically demonstrated that males have higher COVID19 age-adjusted mortality rates within each racial/ethnic group. This study also established that certain racial/ethnic minority groups such as NH Blacks, Hispanics, and NH AIANs had higher COVID-19 age-adjusted mortality rates relative to NH Whites among both males and females. Additionally, sex differences in COVID-19 age-adjusted mortality rates were found to vary markedly in magnitude by race/ethnicity.
The findings of the current study help researchers consider multiple biological, behavioral, and social factors that could contribute to these observed differences in COVID-19 mortality outcomes across the intersection of race/ethnicity and sex.
Biological pathways, for example, may include the proportion of angiotensin-converting enzyme-2 (ACE2) receptors, as well as the severity of T-cell mediated immune responses among men, which have been shown to differ significantly from women. Further, pre-existing health conditions like obesity, hypertension, and cardiovascular diseases among U.S. men are also likely to be contributors to the development of COVID-19. Comparatively, behavioral patterns like smoking, not wearing masks, and ignoring hand washing and sanitizing guidelines may also contribute to men getting COVID-19 more often than women.
Taken together, this data can provide valuable insights to researchers looking to conduct studies with a larger and more global sample size in an effort to elucidate the demographic relationships across races and ethnicities. Such analyses help in strategizing better preventive measures for a novel condition like COVID-19 and can greatly reduce the disease burden.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.