A retrospective analysis of COVID-19 outcomes

Jayne Morgan, M.D., Clinical Director, Covid Task Force, Piedmont Healthcare, Inc.

As a pandemic moves through a population, a number of factors, including both aspects of the virus and of the population, alter its effect on different subsets of the population [1]. Regarding the virus, aspects such as its similarity to other viruses or ways in which it mutates over time can change its impact on subsets of the population or the population as a whole. When a virus is itself a mutation of an earlier virus and/or resembles a virus to which a population has been previously exposed, members of that population may already carry partial immunity to the virus [2,3]. This may lead to differential outcomes for subgroups at baseline. However, even during the course of a pandemic, when there are differences in exposure— such as may happen with healthcare workers, essential workers, and disadvantaged groups during a lockdown— different subgroups may develop immunity faster than others, and/or reach a saturation point at which the majority of the most vulnerable have already been infected or are deceased [4] This means that those groups affected the most in earlier waves can feel less of an impact in subsequent waves both in infection and severity of illness. This phenomenon has been called cross-protection and was first studied in US Army camps across Great Britain during the 1918-1919 flu pandemic [5].

Given the known inequalities faced by Black citizens in the United States during the COVID-19 pandemic, it is plausible that the Black community is one such population that may reach immunity faster than White citizens. Inequalities in Social Determinants of Health (SDOH) can lead to Black populations becoming saturated with and/ or developing immunity to the virus sooner than White populations, leading to a lower infection rate in Black citizens over time, while White citizens, many of whom were able to shelter in place, catch up.

“While we note the change in the demographics of admissions to our hospital at the 5-month mark, the first 5 months demonstrated the full effect of health inequity on a population that was not equipped to protect itself”

We performed a retrospective analysis comparing COVID-19 outcomes of Black and White patients and collected data on all hospitalized patients who tested positive for COVID[1]19in the Piedmont Healthcare System (the single largest healthcare system in the state of Georgia, USA) from March 1, 2020 – December 31, 2020. The final analysis consisted of 9,140 patients 4,584 Black and 4,556 White. Between July and August 2020 was a useful turning point in which to separate the two time periods, not just because it evenly split the first 10 months of the pandemic in half, but also because July 1, 2020 is the date in which entertainment venues and large gatherings were once again permitted in Georgia [6]. Black and White patients were compared within each time period and between time periods at a p < .05 significance level. During Time 1, significantly more Black patients were hospitalized each month than White patients, consistent with past research. However, the difference in hospitalizations between Black and White patients reversed in early August, with more Black patients hospitalized during Time 1 and more White patients hospitalized during Time 2. Mortality rates did not appear to differ from Time 1 to Time 2.

We present these data to emphasize the need to address health equity for Black citizens in the United States. What the COVID-19 pandemic has exposed is what has been hiding in plain sight and laid bare: the ravages of a poorly controlled disease of which the African American community bore the brunt in simply trying to survive. While we note the change in the demographics of admissions to our hospital at the 5-month mark, the first 5 months demonstrated the full effect of health inequity on a population that was not equipped to protect itself. Additionally, it should be noted that as a percentage of the national population, even in the midst of an increase in white admissions during the last 5 months of 2020 within our large hospital system, Blacks were still disproportionately impacted as a whole in comparison to Whites.