Could your ethnicity influence your COVID-19 risk? And if so, why? These are some of the questions that have been keeping Health Data Research UK-funded research fellow Dr Daniel Bean awake at night.

As part of a team from King’s College London led by Dr Rosita Zakeri and Professor Ajay Shah, Daniel securely accessed health records from 872 inner city residents admitted to two South London hospitals with severe COVID-19 (any identifying information was removed to protect their privacy). The researchers compared these patients with similarly deidentified data from GP records of 3,488 people from the same area of London, matched by age and sex.

Besides looking at whether ethnicity increased risk of severe infection, the researchers also used the data to investigate if being from a poorer area (as judged by postcode) or having other long-term health conditions, such as asthma, diabetes or high blood pressure might explain some, or all, of the COVID-19 risk.

Over three months, the team also gathered data on 1,827 adults with COVID-19 admitted to Kings College Hospitals NHS Trust to find out if ethnicity was linked with a higher risk of dying in hospital.

The findings showed that Black and mixed-race ethnicity COVID-19 hospital patients were, on average, a decade younger than white COVID-19 patients. And they were around three times more likely to be admitted to hospital with severe disease. 

Importantly, that increased risk was only partly explained by having underlying health conditions or being from a less wealthy area. And while there was no difference in risk of dying in hospital between Black and white groups, having an Asian background increased the risk of this happening, although it didn’t affect the likelihood of being admitted to hospital in the first place.

Clearly something else is at play here, but the researchers are still scratching their heads as to exactly what might be going on.

“Are there biological factors driving severe infection in certain ethnic groups, is there an interaction between ethnicity and underlying health conditions or other socio-economic factors that we weren’t able to measure in this study? We’re not sure yet, but these are important areas to look at,” says Rosita.

But she certainly thinks that, based on the study findings, ethnic background should be on the radar of doctors and policy-makers when it comes to looking at COVID-19 risk.

“At the moment people recognise that older age, male sex and comorbid diseases are risk factors, but our study confirms that ethnic background should also be considered,” she explains. “As well as biology, social factors like household occupancy, availability of personal protective equipment, occupation and anything that might affect your ability to socially distance should be explored as well.”

Other Health Data Research UK-funded studies support these findings. Dr Claire Niedzwiedz from the University of Glasgow has dug into information from UK Biobank, which holds data on everything from blood pressure to ethnic background for half a million British volunteers. 

When Biobank data was linked with Public Health England test results, Claire was able to track the ethnicity and social background of all study members who became infected between March and May 2020. 

Published in the journal BMC Medicine, her findings showed that black people were three times more likely than white people to get infected, and people of South Asian background had twice the risk. Lower levels of education and disadvantage played a part, but again these things didn’t explain all of the raised risk.

Speed is of the essence when you’re trying to find answers about a deadly pandemic. Daniel says it has been incredibly helpful to link up datasets much more rapidly than would have been possible before these unusual times. 

He adds, “Linkage between different data sets like this is often quite hard to achieve. But because of the pandemic it was recognised that we need to do everything that was possible very quickly, and it allowed us to do this very powerful analysis.”

Although nobody’s names could be seen by the researchers, permission to use this precious health data was granted with the utmost care. 

“Within the hospital, all the decisions about using patient data for Covid are patient-led, by a committee,” explains Daniel. “We’re always very careful about how we use the data, we always use the absolute minimum data that we need and the focus is always about deriving benefit for patients and society from all of the analysis that we do.”

Health data research like this will continue to be important for getting answers about the impact of this deadly new virus for everyone in the UK, and beyond.

Health Data Research UK is working to make health data securely and safely accessible for research to improve people’s lives. Find out more at, and follow on Twitter @hdr_uk and LinkedIn.

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