According to the Centres for Disease Control and Prevention, racial minorities were three times as likely to be hospitalised with covid-19 as whites in 2020. Why? Data scientists at a3.ai, a health-research group, analysed the insurance records of 14m patients in the Covid-19 Research Database, 380,000 of whom were diagnosed with the virus, to disentangle the causes for The Economist. Those racial inequities persist even after controlling for socioeconomic factors. But one notable finding is that Hispanic Americans were the most vulnerable group.
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This analysis has limitations. Only those who filed a medical claim with covid-19 as the diagnosis are listed as having the disease. This may not capture all those who tested positive, and will certainly miss some who were infected. And because the dataset is based on medical claims, its findings may not generalise to those without health insurance. While a3.ai has access to medical data for 110m Americans, only 14m could be associated with race/ethnicity data and filed a claim during the pandemic, about half of whom live in California or Pennsylvania. The data distribution doesn’t necessarily reflect the social and economic makeup of the whole country. Still, these data provide one of the most detailed views so far on the way covid outcomes have varied by race.
Much of the attention paid to racial disparities and covid-19 has focused on the black-white gap. But the Hispanic-white gap is far bigger. Whereas black Americans were 1.3 times more likely to get infected than white Americans, Hispanic Americans were 2.4 times as likely to catch the virus.
Taken together, health and economic status explain some of the disparity, but by no means all. Even controlling for them, nonwhite Americans are still 1.8 times likelier than white Americans to be infected. This means that a non-white middle-class male pensioner with a high school diploma and a pre-existing condition is 80% more likely to get seriously ill from covid than his white peer.
What could the analysis be missing? Essential workers were more likely to be exposed to covid-19 during lockdowns, and non-white Americans are more likely to be essential workers: just over half of non-white Americans have jobs requiring in-person contact compared with 41% of white Americans. But in a separate analysis by a3.ai using additional data to infer patients’ occupations, job type only reduced the racial disparity in odds of covid infection by about one percentage point.
Perhaps non-white Americans disregard public health recommendations more than their white peers, putting them at greater risk? In fact according to the Pew Research Centre, black Americans were more likely than white Americans to consider covid a major threat to their personal health (49% compared with 26%). White Americans were also less likely to support mask-wearing. In June 2020 only 41% of white Americans said that people should always wear a mask in public, compared with 63% of Hispanic Americans and 61% of black Americans.
With everything else seemingly accounted for, that leaves genetic risk factors, which remain mysterious. Hispanic Americans have a higher likelihood of developing non-alcoholic fatty liver disease, potentially resulting from higher prevalence of the pnpla-3 gene, which increases risk of hospitalisation from covid-19. South Asians are more likely to have a gene found in Neanderthals, linked to severe covid-19 symptoms and death. According to a study recently published in Nature, about half of South Asians carry this gene, against only 16% of Europeans. Another study found that black Americans are more likely to have a gene, angiotensin converting enzyme 2, linked to increased covid-19 infections. Dr Harlan Jones of the University of North Texas Health Center warns practitioners to avoid weighing one risk factor over another. Race is complicated, and so are the solutions.■
Sources: a3.ai; Covid-19 Research Database
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This article appeared in the United States section of the print edition under the headline “All of the above”