A case-control and cohort study to determine the relationship between ethnic background and severe COVID-19

Abstract

Background People of minority ethnic backgrounds may be disproportionately affected by severe COVID-19. Whether this relates to increased infection risk, more severe disease progression, or worse in-hospital survival is unknown. The contribution of comorbidities or socioeconomic deprivation to ethnic patterning of outcomes is also unclear. Methods We conducted a case-control and a cohort study in an inner city primary and secondary care setting to examine whether ethnic background affects the risk of hospital admission with severe COVID-19 and/or in-hospital mortality. Inner city adult residents admitted to hospital with confirmed COVID-19 ( n = 872 cases) were compared with 3,488 matched controls randomly sampled from a primary healthcare database comprising 344,083 people residing in the same region. For the cohort study, we studied 1827 adults consecutively admitted with COVID-19. The primary exposure variable was self-defined ethnicity. Analyses were adjusted for socio-demographic and clinical variables. Findings The 872 cases comprised 48.1% Black, 33.7% White, 12.6% Mixed/Other and 5.6% Asian patients. In conditional logistic regression analyses, Black and Mixed/Other ethnicity were associated with higher admission risk than white (OR 3.12 [95% CI 2.63–3.71] and 2.97 [2.30–3.85] respectively). Adjustment for comorbidities and deprivation modestly attenuated the association (OR 2.24 [1.83–2.74] for Black, 2.70 [2.03–3.59] for Mixed/Other). Asian ethnicity was not associated with higher admission risk (adjusted OR 1.01 [0.70–1.46]). In the cohort study of 1827 patients, 455 (28.9%) died over a median (IQR) of 8 (4–16) days. Age and male sex, but not Black (adjusted HR 1.06 [0.82–1.37]) or Mixed/Other ethnicity (adjusted HR 0.72 [0.47–1.10]), were associated with in-hospital mortality. Asian ethnicity was associated with higher in-hospital mortality but with a large confidence interval (adjusted HR 1.71 [1.15–2.56]). Interpretation Black and Mixed ethnicity are independently associated with greater admission risk with COVID-19 and may be risk factors for development of severe disease, but do not affect in-hospital mortality risk. Comorbidities and socioeconomic factors only partly account for this and additional ethnicity-related factors may play a large role. The impact of COVID-19 may be different in Asians. Funding British Heart Foundation; the National Institute for Health Research; Health Data Research UK.

Patient factors and temporal trends associated with COVID-19 in-hospital mortality in England: an observational study using administrative data

“…Other hospital-based studies from the USA and UK support these findings. 10,27,28 A UK study that followed hospital patients until late May noted that South Asian patients had a modestly, but significantly, increased risk of death (hazard ratio 1•19 [95% CI 1•05-1•36]) relative to White patients-very similar to our findings. 27 By contrast, studies of community-based cohorts tend to report significantly higher mortality for patients of Black ethnicity and greater effects of Asian or mixed ethnicities on mortality than we report.…”

“…A recent case-control study for patients admitted to two hospitals in London was able to look at differences in outcomes for community dwellers and hospital patients, with patients of Black and mixed (but not Asian) ethnicities having higher hospital admission rates than community-dwelling controls, but Asian patients having a higher mortality if admitted. 28 Although greater deprivation was significantly associated with higher mortality in our study, this association was modest and much weaker than that described in community-based cohort studies in England. 7 Agestandardised comparisons using ONS data for England and Wales between March 1 and June 30, 2020, found a two-fold difference in COVID-19-related mortality between the most deprived areas (139•6 deaths per 100 000 people) and the least deprived areas (63•4 deaths per 100 000).…”

Impact and Determinants of High-Sensitivity Cardiac Troponin-T Concentration in Patients With COVID-19 Admitted to Critical Care

“…In hospitalized patients, severe illness secondary to COVID-19 is more common in older patients, males, ethnic minorities and those with underlying cardiovascular co-morbidities. 19 , 20 , 21 Our study population characteristics are similar to recently published report of 10,834 patients with COVID‑19 in England, Wales and Northern Ireland. 22 In this large study, severe ARDS was observed in 37% and hospital mortality was 42%.…”

Race-Related disparities in COVID-19 thrombotic outcomes: Beyond social and economic explanations

“…Contents lists available at ScienceDirect EClinicalMedicine journal homepage: https://www.journals.elsevier.com/eclinicalmedicine racial groups. The preliminary results confirming the hypothesis were recently reported by Zakeri et al [6].…”