Disparities in COVID-19 hospitalizations and mortality among black and Hispanic patients: cross-sectional analysis from the greater Houston metropolitan area

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has been a global healthcare and economic catastrophe. The burden of the pandemic has been disparate, with elderly individuals and those with higher burden of cardio-metabolic diseases in the highest risk category [1, 2]. Furthermore, reports have characterized varying levels of evidence suggesting that minority populations have been disproportionately impacted by the Coronavirus Disease 2019 (COVID-19) [3, 4]. Studies from different regions and healthcare systems across the United States have broadly characterized higher susceptibility to infection and hospitalization among Black and Hispanic/Latino populations [5‐9], but fewer differences with respect to mortality [10]. However, no studies, to the best of our knowledge, have systematically evaluated the associations between race/ethnicity and COVID-19 outcomes in Southeast Texas, including the greater Houston area. Such reports are particularly relevant for Black and Hispanic/Latino populations from healthcare systems that serve large, diverse populations, such as in greater Houston, where these minority racial/ethnic groups comprise of approximately 23 and 45% of the overall population, respectively [11]. Of note, in a prior analysis comparing patient characteristics between two surges in COVID-19 cases early on during the pandemic in greater Houston, the proportion of Hispanic/Latino patients from all hospitalizations increased from 25.7 to 43.3% [12]. These knowledge gaps underscore the critical need to characterize the impact of the COVID-19 pandemic on minority populations in Texas.

At the time of this reporting, the greater Houston area had begun to become a hotspot of the COVID-19 pandemic, with over 118,000 confirmed cases of COVID-19 and upwards of 2000 reported deaths [13, 14]. Given the diverse makeup of the region’s population, there is value in investigating how factors related to infection, critical illness, and outcomes are associated with race and ethnicity.

Houston Methodist (HM) is one of the largest healthcare systems in the greater Houston area. Our initial report characterized the racial and ethnic disparities seen with respect to SARS-CoV-2 susceptibility, noting higher susceptibility for SARS-CoV-2 positivity among non-Hispanic Black (NHB) and Hispanic populations, potentially mediated via population density and socio-economic status [15]. In this study, we evaluate racial and ethnic differences in hospitalization and in-hospital mortality among the population testing positive for SARS-CoV-2. Given our prior data, we hypothesized that Black race and Hispanic ethnicity will be independently associated with a higher hospitalization rate and in-hospital mortality in the population of COVID-19 patients across HM.

Between March 3rd and July 18th, 2020, a total of 70,496 unique individuals were tested for SARS-CoV-2, of whom 12,084 (17.1%) tested positive. The mean age across the tested population was 49.9 years and 59.9% were females. Non-Hispanic Blacks (NHB) and Hispanics comprised 19.5 and 20.7% of the tested individuals respectively. Among laboratory confirmed COVID-19 cases, 3536 (29.3%) were hospitalized, of whom 234 (6.6%) experienced in-hospital mortality. The proportions of tested, tested-positive, hospitalized and died individuals by minority race and ethnicity across Houston Methodist are presented in Fig. 1.

Initial reporting from the Houston Methodist (HM) system noted increased odds of SARS-CoV-2 positivity among non-Hispanic Blacks (NHBs) and Hispanics [15]. Our current study expands on these findings and provides a comprehensive view of racial and ethnic disparities across varying stages in the progression of SARS-CoV-2 infectivity and COVID-19 outcomes. Among PCR-confirmed SARS-CoV-2 cases, NHBs and Hispanics were more likely to be hospitalized. No differences in hospital treatment were observed; however, and adjusted in-hospital mortality was non-significantly lower for minority race/ethnicity.

Detailed reports on racial and ethnic disparities from other large healthcare systems have varied across different regions of the United States; however, our findings are similar to those reported following an early investigation from the largest healthcare system in Louisiana which observed a higher likelihood of hospitalization among NHBs but no differences with respect to in-hospital mortality [19]. Similarly, analyses from another single medical center in New York City reported no differences in hospital admission or in-hospital mortality for NHBs; however, Hispanics experienced increased likelihoods of both hospitalization and in-hospital mortality [20]. Overall, higher susceptibility to infection and hospitalization has been broadly observed for minority groups – particularly Blacks [5‐8] and Hispanics [9] – by a range of other studies, with fewer differences found with respect to mortality. Of note, although in our data, specific disease conditions (e.g., diabetes) were reportedly more prevalent among hospitalized NHBs (vs. NHW), overall comorbidity burden was not higher for either minority race/ethnicity group. In addition, the average age of SARS-CoV-2 infections and COVID-19 hospitalizations in our cohort was observed to be lower for NHBs (vs. NHW) and Hispanics (vs. non-Hispanic) which may have contributed relative protection for these patients. Lastly, we note that standardized and intensive care across our hospitals may have narrowed differences in severe disease outcomes. These considerations may partly explain why in-hospital mortality did not differ. It is therefore likely that the population-level burden of SARS-CoV-2 infection and COVID-19–related morbidity and mortality is driven primarily by a greater susceptibility to infection, rather than disparities related to care provision. It is critical to identify specific population-level targets for mitigating the disproportionate impact of the SARS-CoV-2 burden and similar health catastrophes among communities of color.

Interpretation of racial and ethnic disparities should also consider the distinct populations for which epidemiological analyses are being conducted. Whereas our hospital system data demonstrate a greater than twofold likelihood of SARS-CoV-2 infection among both racial and ethnic minority groups, publicly available data indicate that, in Houston, the population ratio of Black-to-White race is 0.91 but among the SARS-CoV-2 positive cases this ratio is 0.84 (demonstrating proportionately lower infection rates among Blacks) (Supplemental Table 3). Conversely, the population ratio of Hispanic-to-non-Hispanic ethnicity is 0.81 but this ratio in the SARS-CoV-2 positive population is 0.85. Given this contrast between our findings and publicly reported data, it is important to note that the ratios for infection rates presented above reflect a snapshot of case prevalence. Our analyses do attempt to account for this when comparing the likelihoods of infection, hospitalization, or in-hospital mortality among our base cohorts. Furthermore, the differences may be explained, in part, by testing characteristics across a healthcare system; our data reflect characteristics of individuals who sought out point-of-care testing but do not capture the full scope of testing that is occurring at public or community-based sites across greater Houston. Presumably, we might expect differences in the location of preference for testing, based on an individual’s perception of need or convenience. In contrast to what we observed in Houston, the population Black-to-White ratio in New Orleans is 1.95, but the SARS-CoV-2 infection and death Black-to-White ratios are 3.20 and 3.25, respectively. Similarly, higher Black-to-White ratios for SARS-CoV-2 infection, hospitalization and mortality (compared with the population Black-to-White ratio) were observed for New York City and Chicago. Supplemental Table 3 presents available case and region demographics for a selection of major U.S. metropolitan areas. However, several gaps remain in reporting of race and ethnicity-based metrics.

Limitations of our study include use of data from a single healthcare system across the greater Houston area. Although HM serves patient populations in communities located beyond the metropolitan area, hospital data may not be representative of a generalized population. Moreover, our work is driven by analysis of healthcare utilization data; consequently, it is likely that differences in care utilization would influence the patient population represented in our data. Whereas NHBs and Hispanics make up an approximate 23 and 45% of the greater Houston area population [11], they comprised only 19.5 and 20.7% of our testing cohort. Given these differences, disproportionate testing characteristics may have biased our data. The findings from our study need to be replicated across large and diverse healthcare systems and evaluated in light of specific demographic contexts in the region. Additionally, given the observational nature of our study, all estimates are associative and do not imply causation. In particular, we did not perform adjusted analyses for factors associated with hospitalization or mortality, as that was not the focus of this study. Any association observed in our bivariable analysis of factors related to morality or hospitalization would warrant separate validation analyses to be of interpretational value. Although our EHR captures a comprehensive array of information reported across encounters at our hospital system, a complete account of individual medical histories is not available. Median household income and population density were included as approximations of socioeconomic and social distancing challenges; however, the true effects are undoubtedly more complex and multifactorial in nature [21, 22]. Future analyses should employ additional population measures to account for social determinants of health.

The need to identify the root causes of the disparate burden of the SARS-CoV-2 pandemic among communities of color as precisely as possible should lead healthcare officials and institutions to focus the public health messaging on appropriate targets. Such efforts would be particularly valuable for mitigating disparities at the onset of future public health crises. Our data demonstrate that, despite a higher likelihood of infection and hospitalization among NHB and Hispanic populations, there were no subsequent differences in hospital treatment or in-hospital mortality. These findings support the hypothesis that the overall higher burden of the COVID-19 pandemic among racial and ethnic minorities may be driven by higher susceptibility to contracting the SARS-CoV-2. Such susceptibilities are most likely mediated by adverse social determinants of health, which puts these minority populations at risk of infection in the community setting.