The COVID-19 pandemic remains a serious threat to human life. The cause of this pneumonia has since been identified and named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has a phylogenetic similarity to SARS-CoV 1 .
Though the origin of the SARS-CoV-2 is strongly believed to be zoonotic, propagation in communities and around the globe has been mainly facilitated by humans 2 . Though the world ramped up efforts to contain the virus, limit its spread and This article is protected by copyright. All rights reserved.
curb morbidity and mortality, propagation and mortality continued at exponential rates and now officially recognized as a pandemic 3 . The global mortality is reported as about 2.5% 4 , but mortality among hospitalized patients is significantly higher, with preliminary reports of death rates as high as 24.5% among intubated patients in New York 5 .
African-Americans have been disproportionately affected in terms of incidence and mortality. The attack rate and fatality rates are disproportionately higher compared to other racial groups [6] [7] [8] . Though it is highly speculated that the prevailing relatively poor health is the primary driver, evidence remains sparse and constitutes an area of ongoing research. Generally speaking, predictors of death among patients with COVID-19 remain poorly understood and elucidated. It is in this light that we set out to establish the clinical characteristics and predictors of mortality among African Americans with COVID-19 managed at an inner-city community teaching hospital in New York.
We conducted a retrospective cohort study among patients hospitalized and managed for the COVID-19 infection at an inner-city teaching hospital located in Downtown Brooklyn, New York. Our hospital serves a predominantly African-American population. At least 90% of all patients seen at our main hospital and clinics are African-Americans. Included in our study were all African-American patients admitted and managed for laboratory-confirmed COVID-19 infection with a definitive outcome (discharged or deceased) at the end of data collection.
Ethical clearance was obtained from the hospital's IRB committee. Because our study was limited to chart review with no patient interactions, the requirement for informed consent was waived.
Recruitment was systematic over the entire data collection period from March 1st through April 9th, 2020. Demographic, social, clinical, laboratory, and radiologic data This article is protected by copyright. All rights reserved.
were extracted from electronic medical records and entered on an excel data collection sheet. The data collection sheet had inbuilt checks to flag probably incorrectly entered or inappropriate data prompting immediate corrective actions to limit inaccuracies. To further ensure data extraction was accurate and complete, 10% of all cases (approximately 40) were randomly assessed for validity and consistency by an independent evaluator (part of the research team) and found to be accurate.
Nasopharyngeal swabs were obtained at the time of admission, and COVID-19 was confirmed by the qualitative SARS-CoV-2 Real-time polymerase chain reaction. All laboratory methods were in accordance with prescribed standards by regulations.
Laboratory tests included blood gases, lactic acid, complete blood count, coagulation profile including d-dimers, serum biochemical tests (including renal and liver function, creatine kinase, lactate dehydrogenase, and electrolytes), troponin I, interleukin-6 (IL-6), serum ferritin, and procalcitonin among others. Chest radiographs, as well as electrocardiograms, were obtained for all patients at the time of presentation. Inpatient management was mainly supportive with respiratory assistance and management of associated co-morbidities as directed by the treating physicians. Patients were either discharged when clinically stable or if they died during the course of hospitalization. Negative virologic results were not a prerequisite for discharge.
Continuous and categorical variables are presented as median (IQR [Interquartile range]) and frequency (%), respectively. We used the Mann-Whitney U test, χ 2 test, or
Fisher's exact test to compare differences between survivors and non-survivors where appropriate. To identify predictors of in-hospital mortality, univariable and multivariable binary logistic regression were sequentially applied. We adopted a stepwise approach in building the ultimate multivariate model for identifying predictors of mortality. First, from univariate analysis, we retained for multivariate models all variables with p-values of ≤0.10. We then proceeded to establishing an intermediate "mini" multivariable model consisting of demographic data and comorbidities, symptoms at presentation and triage vitals, and finally, laboratory data. This article is protected by copyright. All rights reserved.
Because of wide variations in laboratory variables, with most values above the upper limit of normal, categorizing them by normal or abnormal following laboratory reference ranges would have produced unequal groups with major implications for analysis. Also, this will be less informative as we believe that not just the abnormal value is worrisome but the degree of abnormality, too. To address this, we transformed all laboratory variables into categorical variables with two categories:
One category consisting of patients with values less than the 75 th percentile and the second category consisting of patients with values ≥75 th percentile. We, therefore, compared outcomes between patients with values in the 4 th quartile to those patients with values <75 th percentile. The final model consisted of all variables with p values <0.10 from the three "mini" intermediate models mentioned above and presented using forest plots for easy visualization. All data analysis was done using STATA-16 with two-sided p-values less than 0.05 considered statistically significant.
In all, 408 African-Americans were admitted and managed at our hospital through the conclusion of the data collection period with an inpatient mortality rate of 33.35%.
About 57% of all study participants were men with no gender differences in mortality.
The median age of participants was 67years with non-survivors with a median age of 71years being significantly older than survivors with a median age of 63years, p<0.001. The main co-morbidities were hypertension, diabetes, chronic kidney disease, and dyslipidemia, with a prevalence of 66.42%. 43.24%, 16.90% and 16.18%, respectively. Persons with hypertension, diabetes, cerebrovascular accident, and chronic kidney disease were more likely to die compared to those without. Detail characteristics and co-morbidities among study participants are shown in table 1.
The most prevalent symptoms on presentation were cough, fever/chills, myalgia, Accepted Article myalgia were more likely to die, comparatively. Also, persons with lower oxygen saturation increased respiratory rate, and increased systolic blood pressure was more likely to die than their respective counterparts. Table 2 shows more details of symptoms and triage vitals at the time of presentation.
There was a statistically significant difference in several laboratory markers such as serum ferritin, CRP, interleukin 6, white blood cells, and lactate dehydrogenase between survivors and non-survivors. Other markers such as troponin, BNP, Ddimers, lactic acid, and plasma glucose were also significantly different between survivors and non-survivors. Table 3 shows detailed distributions of laboratory parameters in our study population and by subgroups of the deceased and survived.
Age and BMI were independent predictors for mortality. In fact, for each unit increase in age and each unit increase in BMI, the odds of dying were 1. intubation is evident, irreparable damages might have been suffered by the body. We, however, think future death rates would be at least lower than current estimates as we learn on the job on how to best manage these patients. Also, we are a population being exclusively African-American, which has been reported to have higher mortality rates compared to other races 8 .
Consistent with prior authors, age was an independent predictor of mortality even after adjusting for several known confounders 8 . This might suggest that the virus takes advantage of the natural decline in health state with increasing age to cause a severe and deadly infection. Most persons with severe disease requiring admission were the elderly, and deaths in persons less than 50years were not common. This warrants aggressive protective strategies for all elderly persons to limit exposure as active infection in the elderly carries a very poor prognosis, at least for now, until better management strategies are developed. This observation poses a severe threat to the survival of the rapidly expanding elderly population. There is, therefore, a need for aggressive research on prevention and management strategies in order to adequately address this infection and curb the unacceptable toll on the aging American population. Consistent with other authors 15 , BMI was also an independent predictor of mortality. This highlights the fragile nature of health among patients with elevated BMIs, through both identified and yet to be identified pathways. This is all This article is protected by copyright. All rights reserved.
the more concerning as obesity prevalence continues rising at faster rates in the general population 16 if COVID-19 were to be around for a longer duration.
Severely elevated serum ferritin and CRP, which are markers of acute inflammation from various causes: Infection (Bacterial/Viral), injury, trauma), were independent predictors of mortality. This suggests that the pathophysiologic pathway may involve acute severe inflammatory response, as noted by markedly elevated levels of proinflammatory markers. This is consistent with other reports suggesting a cytokine storm as a possible pathophysiologic mechanism for COVID-19 17 . Whether 
Data recruitment was done at a single hospital and focused exclusively on African-Americans and thus makes the generalization of our findings difficult. However, This article is protected by copyright. All rights reserved.
recruitment at a single-center ensures that there are no considerable discrepancies in management strategies that could have influenced outcomes as there is no universally agreed standard of care for these patients at this time with substantial interhospital differences in management. Secondly, data was obtained from charts with inherent shortcomings as validity and accuracy of information are based on recorded data.
However, thorough chart review and validation by an independent reviewer ensured that obtained information was accurate and complete. Notwithstanding these shortcomings, our study is the first to provide an exclusive report on the clinical characteristics of African-Americans hospitalized and managed for COVID-19
infection in the USA. Also, though exclusively focused on African-Americans, our studies provide insights into predictors of mortality among hospitalized patients with COVID-19, paving the way for future research as we commit to unraveling the mystery associated with COVID-19 infection.
Cough, shortness of breath, fever/chills, gastrointestinal symptoms, and myalgia were the predominant presentation among African-Americans hospitalized with COVID-19
infection. Advanced age, higher BMI, elevated serum ferritin, CRP, and D-dimers at the time of presentation are independent predictors of mortality among hospitalized Africa-Americans with COVID-19 infection.
Funding: There was no funding for the study 