Up to one in six people with COVID-19 report long COVID symptoms

29th June 2022 – King’s College London

One in six (17%) middle-aged people who report being infected by SARS-CoV-2 also report long COVID symptoms, while this falls to one in 13 (7.8%) among younger adults who reported having Covid-19, according to a new study led by King’s and UCL which is now published in Nature.

coronaviruses

The preliminary findings, part of the UKRI-NIHR funded multi-institution CONVALESCENCE study and submitted to the preprint server medRxiv, also found that women were 50% more likely to report long COVID than men, and that the risk for long COVID symptoms increases with age, is linked to poorer pre-pandemic mental and physical health and is associated with a previous diagnosis of asthma. Non-white ethnic minority groups had lower odds of reporting long COVID (about 70% less likely).

Using a stricter definition of long COVID as 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 researchers analysed anonymised data from 1.2 million primary health records across the UK together with 10 population-based cohort studies with 45,096 participants. Using existing cohort studies, whose participants are surveyed regularly, allowed the research team to include cases not reported to the GP and to look at people’s health before the pandemic.

Knowing which factors increase the risk of long COVID is an important first step in understanding how best to prevent and treat this condition.

Professor Nishi Chaturvedi (MRC Unit for Lifelong Health and Ageing at UCL), who leads the ongoing CONVALESCENCE study, 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.”

First author Dr Ellen Thompson, of King’s College London, said:

“It’s really important to identify risk factors in the population so we can prepare and devise prevention strategies, protecting people at increased risk of poor outcomes from COVID-19.”

First author Dr Dylan Williams (MRC Unit for Lifelong Health & Ageing at UCL) said:

“Amassing this body of evidence would usually take many months or years to assemble but we achieved this more quickly through massive, constant collaboration by researchers at many different institutions.

Dr Claire Steves from the School of Life Course Sciences said:

“Our findings hint at the mechanisms behind long COVID. Next, we need to identify the predispositions that might explain, for example, why women or individuals with asthma appear to be at higher risk. Could a liability to suffer from autoimmunity or allergies play a role? Establishing concrete research avenues to go down will eventually lead to benefits for people with long COVID.”

The study forms part of the larger COVID-19 Longitudinal Health and Wellbeing National Core Study, which is investigating the health, social and economic impacts of the COVID-19 pandemic by combining rich pre-COVID data collected from participants of numerous national research studies with national anonymised electronic health records.

The researchers investigated if the risks of developing long-term Covid symptoms differed by several pre-pandemic socioeconomic and health characteristics. Coordinated analyses of the longitudinal studies and health records data showed consistently that female sex and increasing age (up to 70 years) were associated with increased odds of long COVID.

Pre-existing adverse mental health was associated with a 50% increase in the odds of reporting long COVID, while asthma was the only specific prior medical condition consistently associated with greater risk of developing lasting Covid-19 symptoms (a 32% increase). Participants were identified as having pre-existing adverse mental health if they had been diagnosed with one of a number of conditions such as depression and bipolar disorder, or their responses to questionnaires indicated they had a mental health condition before the pandemic.

Analysis was conducted on 6,899 individuals self-reporting COVID-19 from 45,096 surveyed adult participants of ongoing longitudinal studies in the UK, and on 3,327 cases assigned a long COVID code in primary care electronic health records out of 1,199,812 adults diagnosed with acute COVID-19. Long COVID, identified as Post-COVID-19 syndrome in the study, is defined as symptoms persisting for longer than 12 weeks after the initial infection.

The research team included researchers at the Universities of Bristol, Edinburgh, Glasgow, and Oxford, as well as the London School of Hygiene & Tropical Medicine, and the Bradford Royal Infirmary.

Dr Fiona Glen, programme director for the NICE Centre for Guidelines, said:

“There is still much we do not know about the long-term effects of COVID-19. We continue to monitor and assess the latest evidence on the long-term effects allowing us to continuously update our guideline recommendations. We welcome this new research which will ensure we have a better understanding of how to manage the care and treatment of patients with prolonged symptoms of COVID-19.”

Your Contribution to COVID-19 Research

10th February 2022 – By Aaruthy Suthahar

Woman holding beaker and notepad

In October 2020, the National Core Studies commenced as part of the UK’s response to the COVID-19 pandemic. The National Core Studies are using health data to rapidly inform policy to help us get through the pandemic. 

TwinsUK is closely involved in the Longitudinal Health and Wellbeing National Core Study, which aims to understand the health, social and economic impacts of the pandemic. We are one of many UK longitudinal population cohorts taking part in the project.  

This large, multi-institution team is working together to answer key questions across several different areas. Current priority research questions include: how was healthcare disrupted by the pandemic; did government schemes such as furlough help; how was mental health impacted by the pandemic; how well do vaccines work; and what are the short and long-term consequences of infection on health.  

The team has prioritised questions that harness the unique aspects of cohorts like TwinsUK, such as extensive pre-pandemic data. By working together and triangulating analysis in longitudinal health cohorts and electronic health records, we can provide robust evidence to inform policy. 

Findings are regularly reported to the government’s Scientific Advisory Group for Emergencies (SAGE) and the Cabinet and have influenced NICE guidelines, which dictate how to treat medical conditions.  

Results and impact so far 

Every day we are learning more about COVID-19 and its impact, thanks to our TwinsUK members taking part in studies and questionnaires and our researchers rapidly analysing all the data coming in. Below are some key examples to date that TwinsUK was involved in: 

Society and Health: The coronavirus job retention scheme was associated with the preservation of health behaviours (eating, drinking, smoking, sleeping habits) similar to those remaining in employment, and more favourable to those who become unemployed. Also, while mental and social wellbeing declined in those furloughed, the effects were far less than those who lost their jobs. This suggests that social protection policies should be implemented in the post-pandemic recovery period and during future economic crises.  

Healthcare Disruption: The pandemic led to unequal healthcare disruptions. Females, ethnic minorities, and disadvantaged people were most affected. Action is needed to prevent the widening of existing health inequalities, and efforts to ensure continuity of care during pandemic-related disruptions may need to be more clearly targeted to those who most need that care.  

Mental Health: People with prior mental ill-health were hit harder by pandemic disruption. Inequality between those with and without mental health problems should be considered when provisioning current and post-pandemic health, economic, and well-being support. Also, a substantial deterioration in mental health seen during the first lockdown did not reverse when lockdown was lifted, suggesting that lockdown alone was not responsible for the decline in mental health. There is a need for investment in mental health support to address all underlying causes.  

Long COVID: We found that long COVID is associated with women, middle age, and pre-existing health factors, including asthma. Understanding why different groups of people have different levels of risk could both identify high-risk groups and help us understand how best to prevent and treat long COVID.  

What are we working on now? 

We are currently working with collaborators at University College London (UCL) to carry out a detailed study of how COVID-19 affects the body. This will help us understand long Covid, which is when infected individuals continue to experience symptoms for many weeks and even months after infection.  

This study will recruit people with a range of COVID-19 experiences, and participants will be invited to UCL’s clinic in London for a full day of checks and health tests, including an MRI scan. TwinsUK is the first cohort to recruit participants to CONVALESCENCE, which aims to recruit 800 participants in total. We have recruited more than 150 twins to take part, mainly in twin pairs.  

A big thank you 

We would like to take this opportunity to thank our twins for everything they have contributed to this vital research, both by taking part in sample collection and questionnaires during the pandemic, but also for all of the data they have previously provided to TwinsUK, which is essential to understand how the pandemic has affected health.  

TwinsUK’s Dr. Claire Steves is a senior researcher working across the National Core Study and CONVALESCENCE. Dr. Steves explained: 

“There is a wealth of data in the UK’s population cohort studies and linked health records. The pandemic has shown the importance of using these unique resources to answer key questions about public health and inform policy as quickly as possible.”

“I would like to thank each and every one of our twins for the vital role they are playing in defeating COVID-19.” 

If you would like more information on our COVID-19 research, please click HERE.  

Cycling for COVID-19 – Professor Tim Spector’s fundraising challenge

10th August 2020 – by Paz García

It’s time to limber up for Professor Tim Spector, as he will be cycling 100 kilometres and swimming 1.5 km this weekend in order to raise money for the COVID Symptom Study.

The COVID Symptom Study app has more than 4 million users in the UK and the regular logs by participants have enabled researchers to make key discoveries about COVID-19.

For example, the widespread use of the app provided crucial data for understanding the spread and progression of the virus, such as confirming that loss of taste and smell – anosmia – was a bizarre yet distinct symptom of COVID-19.

Professor Spector said:

“To our supporters, those who’ve donated and those who have diligently reported their symptoms on the CV-19 app, the COVID Symptom Study team are extremely grateful for your contributions.

“Thank you, and stay safe and well.”

To donate, visit Tim’s fundraising page available here.

COVID-19 prevalence and severity higher in urban and most deprived areas

29th April 2020

COVID-19 is disproportionally more common and more severe in people living in urban areas and regions of higher poverty, a new study from the Department of Twin Research reports. 

These results come from the analysis of the health data logged by more than 2 million people over 24 days on the COVID Symptom Tracker app in the UK. 

The team also found that COVID-19 cases and severity has decreased since the lockdown began. 

These results illustrate how data from symptom tracking apps can be used to successfully monitor the pandemic over time, helping to identify areas that need more support and healthcare resources to cope. 

As part of the response to the COVID-19 pandemic, researchers at King’s College London and healthcare science company ZOE developed the COVID Symptom Tracker app. More than two million UK users nationwide are now using it to report daily updates on symptoms, healthcare visits and COVID-19 testing results. 

The team studied 2,266,235 unique app users reporting daily on COVID-19 symptoms, hospitalisation, COVID-19 test outcomes, demographic information and pre-existing medical conditions over 24 days immediately following the introduction of major social distancing lockdown measures announced by Prime Minister Boris Johnson on 23rd March 2020. 

On the link between COVID-19 and poverty, lead researcher Dr Cristina Menni said: 

“This could reflect that individuals in more deprived areas are more exposed or vulnerable to the virus.  It may be that they work in jobs requiring work out of the home, where they are more likely to be exposed to circulating virus. We know from previous research that deprivation is closely linked with increased health issues and disease burden; our results suggest that COVID-19 is no exception.” 

Dr Claire Steves, joint senior author said: 

“This finding is important for allocation of resources in this pandemic.  Areas with higher rates of poverty will need greater supply of PPE and more hospital capacity.  This is likely to continue to be important when the social distancing measures are eased.” 

The map below shows the identified hotspots in red:

The research paper with the full findings is available in non-peer reviewed archive format at the medRxiv site here

Latest data from COVID Symptom Tracker app shows the lockdown is working

8th April 2020

The latest analysis of data from the COVID Symptom Tracker app, used by over 2 million people, shows the rate of new symptoms being reported nationally has slowed down significantly in the past few days.  The latest figures estimate that 1.4 million people in the UK aged 20-69 have symptomatic COVID, a fall from 1.9 million on the 1st April. 

These figures suggest that the nation staying home is having a big impact on the spread of the virus in the UK. The drop in new symptoms indicates that although the number of hospital admissions and deaths from COVID are currently rising, they should start to fall in about two weeks provided social distancing continues. This two week lag is caused by the delay between symptoms starting and becoming very severe.  

This data from millions of people lines up with what has been reported by NHS digital based on much smaller numbers. They show a decline in the number of calls to NHS 111 with COVID since the 22nd March.

While symptoms have been decreasing nationally, in all areas there are still many people with active symptoms of COVID. Therefore, this data supports both the success of lockdown, and the importance of maintaining it. It also shows that individual areas vary. Most of the country’s larger cities like London, Birmingham, Glasgow, and Liverpool continue to have very high levels of symptoms in the community, even this far into lockdown. Other hotspots include South Wales. There are significantly higher levels of symptoms across the Midlands, the North of England and Southern Scotland than in the South West of England. 

Lead researcher Professor Tim Spector said:

“It is really encouraging to see that the rate of new symptoms being reported is beginning to fall. Even though hospital admissions and deaths are still on the rise, we hope that these figures offer a much needed light at the end of the tunnel. 

We have been totally blown away by the public’s response to the app. On the first day we saw one million members of the public download the app making it one of the most successful first days for an app ever, and already probably the UK’s largest citizen science project. The altruism of the UK public combined with modern technology is allowing us to rapidly collect huge amounts of invaluable data to help us better understand this deadly virus.

We would like to take this opportunity to thank every single person who is already participating and would urge everyone else to download the app and check in every day, whether you are experiencing any symptoms or feeling fine.”

Developed by researchers at King’s College London and healthcare science company, ZOE, the COVID Symptom Tracker has been used to log symptoms by over 2 million people across the UK, with over 10 million individual reports so far. Members of the public are using the app to track their daily health whether they are healthy or showing potential COVID symptoms. It is also being used by healthcare and hospital workers nationwide so their increased risk can be recorded.

The research team at King’s College London and ZOE are working round the clock to analyse the data to generate new insights about the disease and its progression. For example, they have discovered that loss of smell or taste is more predictive of COVID in the population than the classical symptoms of fever and cough. An interactive map allowing anyone to see the distribution of COVID in their area is available at covid.joinzoe.com as well as frequent science updates.

The researchers have developed a statistical model which analyses millions of COVID Symptom Tracker data points, including thousands of people who have had tests for COVID, in order to predict which combination of symptoms indicate someone is likely to test positive for COVID. This model is then applied to the UK population aged 20-69 and then mapped to the regions of the country accounting for age and gender differences to provide maps over time. The most predictive individual symptoms, in order of importance were: lack of taste & smell, fatigue, shortness of breath, fever and persistent cough. The model estimates that 3.5% of these app users would be positive if tested. As contributors continue to share symptoms, and we link it to other health records, the model will become more accurate and sophisticated.

The app is available to download from the Apple App Store and Google Play from the links at covid.joinzoe.com.

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