Ethnic disparities in COVID-19: increased risk of infection or severe disease?

Rohini Mathur and colleagues found that Black and Asian ethnic groups were more likely to have adverse COVID-19 outcomes compared with the White population, even after accounting for differences in sociodemographic, clinical, and household characteristics. These findings are timely and striking, in light of the Commission on Race and Ethnic Disparities’ recent report, which has been criticised for suggesting that the “claim the country is still institutionally racist is not borne out of evidence”.

We note that Mathur and colleagues did not adjust for the risk of testing positive for SARS-CoV-2 during the second wave. If, by adjusting for the risk of infection, the higher risk of severe disease in South Asians compared with White groups is nullified, this suggests that, potentially, factors relating to increased exposure to the virus, such as being an essential worker, could explain most of the increased risk. However, should the risk of intensive care admission and death remain high, this suggests that South Asian groups might be biologically more likely to develop severe disease once infected compared with White groups (appendix).

Future studies must aim to disentangle the two risks because, if minority ethnic groups are disproportionately affected by COVID-19 mainly because of an increased risk of infection, it will be clearly due to inequalities that predispose them to exposure—such as living within multigenerational settings or being an essential worker. A focused public health approach that prioritises lowering the risk of SARS-CoV-2 infection in those predominantly at risk of exposure would also prevent disproportionate death.

KRA has served as a paid consultant, providing unrelated methodological advice, to AbbVie, Amaris, Allergan, Astellas, AstraZeneca, Boehringer Ingelheim, Bristol-Meyers Squibb, Creativ-Ceutical, GlaxoSmithKline, ICON/Oxford Outcomes, Ipsen, Janssen, Eli Lilly, Merck, NICE, Novartis, NovoNordisk, Pfizer, PRMA, Roche, and Takeda; has received research funding from the Association of the British Pharmaceutical Industry, European Federation of Pharmaceutical Industries & Associations, Pfizer, Sanofi, and Swiss Precision Diagnostics; and is a partner and director of Visible Analytics. MP reports grants and personal fees from Gilead Sciences and personal fees from QIAGEN, unrelated to this Correspondence. All other authors declare no competing interests.