Published: 24 June 2021
Up to one in three people who report being infected by SARS-CoV-2 also report long COVID symptoms, with older people and women more likely to be affected.
Two research studies, funded by the NIHR and UK Research and Innovation, have assessed the prevalence of long COVID in large groups of people who have experienced COVID-19.
The REACT long COVID (REACT-LC) study, led by researchers at Imperial College London, used self-reported data from 508,707 adults aged 18 and above surveyed between September 2020 and February 2021.
Of the people who reported having had COVID-19, over a third reported persistent symptoms lasting at least 12 weeks, or long COVID. Around one in 10 reported severe long COVID symptoms.
The findings from the REACT-LC study suggested that the likelihood of experiencing long COVID increases with age, with a 3.5% increase in likelihood in each decade of life.
The research also showed that the risk of long COVID was higher among women, people who are overweight or obese, and those who smoke, live in deprived areas, or had been admitted to hospital. The risk of long COVID was lower in people of Asian ethnicity.
Professor Paul Elliott, director of the REACT programme at Imperial College London, said: “Our findings do paint a concerning picture of the longer-term health consequences of COVID-19, which need to be accounted for in policy and planning.
“Long COVID is still poorly understood, but we hope through our research that we can contribute to better identification and management of this condition, which our data and others’ suggest may ultimately affect millions of people in the UK alone.”
The CONVALESCENCE study, led by researchers at UCL and King’s College London, analysed anonymised data from 1.2 million primary health records across the UK, together with data from 45,096 participants in 10 population-based cohort studies.
The study found that one in six (17%) middle-aged people who reported having had COVID-19 also reported long COVID symptoms, with this figure falling to one in 13 (7.8%) among younger adults. Using a stricter definition of long COVID as symptoms impacting routine daily activities, the researchers found that it affected 1.2% of 20-year-olds who had COVID-19, but 4.8% of people in middle age.
The preliminary findings from the CONVALESCENCE study also found that women were 50% more likely to report long COVID than men. In addition, the risk of long COVID was linked to poorer pre-pandemic mental and physical health and was associated with a previous diagnosis of asthma.
Non-white ethnic minority groups had lower odds of reporting long COVID (about 70% less likely).
Professor Nishi Chaturvedi, from the MRC Unit for Lifelong Health and Ageing at UCL, said: “Getting consistent findings from this combination of many different studies gives us greater confidence that our findings are robust, which is critical given that we know so little about long COVID.”
Dr Claire Steves of King’s College London, senior author of the paper, said: “Knowing which factors increase the risk of long COVID is an important first step in understanding how best to prevent and treat this condition.”
The NHS has opened over 80 long COVID assessment services across England, and last week the NHS published a £100 million plan to expand support, including £30 million to help GPs improve diagnosis and care for patients with long COVID.
Health and Social Care Secretary Matt Hancock said: “I know long COVID can have a lasting and debilitating impact on the lives of those affected. Studies like this help us to rapidly build our understanding of the impact of the condition and we are using these findings and other new research to develop support and treatments.
“We are learning more about long COVID all the time and have made £50 million of research funding available to support innovative projects, with clinics established across the country to help improve the treatment available.”