Data from millions of users of the ZOE COVID Symptom Study app shows striking ‘hotspots’ of COVID-19 in urban and poorer areas across the UK, revealing how the disease affects different social groups within the population and highlighting where to target health interventions and resources. 

The findings come from a new analysis published in the journal Thorax, led by researchers at King’s College London. 

To understand more about how COVID-19 has affected different parts of the population, the researchers analysed data from more than 2.27 million UK app users who had logged health reports for 24 days following the first UK lockdown in March 2020.

They then compared the app data against geographic, socioeconomic and demographic information such as age and gender, as well as underlying health conditions and hospitalisations from COVID-19.

Searching for hotspots

The researchers found a greater prevalence of COVID-19 and more severe cases in urban centres compared with rural locations, and in poorer areas compared with richer ones. 

This could reflect the fact that people in more deprived areas are more likely to have jobs where they can’t work from home, making them more likely to be exposed to COVID-19.

The team discovered higher COVID-19 prevalence and severity in areas with more people living in each household, while places with higher levels of air pollution also had increased rates of COVID-19.  

The study confirms that obesity, smoking and lung disease are risk factors for becoming severely ill with COVID-19, although they don’t seem to make it more likely that someone will catch the disease in the first place.

The data revealed a drop in the prevalence and severity of predicted cases of COVID-19 over time, suggesting that the UK-wide lockdown measures were working. 

However, persistent hot-spots remained in a number of places including London, Birmingham, Wolverhampton and Liverpool, highlighting that control measures and public compliance may have not have been strong enough in these areas.

Protecting everyone

“We already know that social factors like poverty and pollution affect people across their lifetime, leading to poorer health and deepening inequalities, and our analysis shows that COVID-19 follows the same pattern,” says lead researcher Dr Claire Steves from King’s College London.

“It’s vital that policymakers focus on protecting people living in poorer, more polluted urban areas through effective prevention measures and allocation of appropriate healthcare resources.” 

Professor Tim Spector, ZOE COVID Symptom Study app lead and Professor of Genetic Epidemiology at King’s College London adds, “This study shows how data from the millions of ZOE app users is helping us to monitor COVID-19 and uncover key new findings like this one on the importance of deprivation in COVID. Rapid access to data is essential to informing the UK’s response to COVID-19. The app is a prime example of how self-reported health data can be used quickly and cost-effectively to understand what’s happening as the disease spreads.”

We can’t do this without you

Our millions of app users have helped us demonstrate that the ZOE COVID Symptom study is accurate, reliable, cost-effective and useful. 

We need as many people as possible across the UK to download and use the app daily to provide the data we need to help us follow the pandemic over the months ahead as we wait for vaccination to catch up.