28 September 2021
- 37% of people had at least one long-COVID symptom diagnosed in the 3-6 month period after COVID-19 infection.
- The most common symptoms were breathing problems, abdominal symptoms, fatigue, pain and anxiety/depression.
This new study from the University of Oxford and the National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre (BRC) investigated long-COVID in over 270,000 people recovering from COVID-19 infection, using data from the US-based TriNetX electronic health record network.
The study reports on how commonly nine core long-COVID symptoms were diagnosed, and how this rate compared to people recovering from influenza. The nine core long-COVID symptoms, occurring 90-180 days after COVID-19 was diagnosed, comprise:
- Abnormal breathing – 8%
- Abdominal symptoms – 8%
- Anxiety/depression – 15%
- Chest/throat pain – 6%
- Cognitive problems (‘brain fog’) – 4%
- Fatigue – 6%
- Headache – 5%
- Myalgia (muscle pain) – 1.5%
- Other pain – 7%
- Any of the above features – 37%
Higher rates were seen if the whole 1-180 day period after COVID-19 infection was included.
Severity of infection, age, and sex affected the likelihood of long-COVID symptoms: long-COVID symptoms were more frequent in those who had been hospitalised, and they were slightly more common in women. These factors also influenced which of the symptoms people were most likely to experience. For example, older people and men had more breathing difficulties and cognitive problems, whereas young people and women had more headaches, abdominal symptoms and anxiety/depression. Many patients had more than one long-COVID symptom, and symptoms tended to co-occur more as time progressed.
The study also looked at the same symptoms in people recovering from influenza. Long-COVID symptoms did occur after influenza, but were 1.5 times more common after COVID-19.
This study does not explain what causes long-COVID symptoms, nor how severe they are, nor how long they will last. The results do not take into account people who had COVID-19 but were not diagnosed, e.g. because they were asymptomatic and did not get tested, nor COVID-19 survivors with long-COVID symptoms that had not been recorded in their health records.
NIHR Academic Clinical Fellow, Dr Max Taquet, who led the analyses, University of Oxford, said: ‘The results confirm that a significant proportion of people, of all ages, can be affected by a range of symptoms and difficulties in the six months after COVID-19 infection. These data complement findings from self-report surveys, and show that clinicians are diagnosing patients with these symptoms. We need appropriately configured services to deal with the current and future clinical need.’
Professor Paul Harrison, who headed the study, Department of Psychiatry, University of Oxford, said: ‘Research of different kinds is urgently needed to understand why not everyone recovers rapidly and fully from COVID-19. We need to identify the mechanisms underlying the diverse symptoms that can affect survivors. This information will be essential if the long-term health consequences of COVID-19 are to be prevented or treated effectively.
Notes to editors:
For further information, please contact: Genevieve Juillet, Media Relations Manager (Research and Innovation), University of Oxford, email@example.com
This new paper, Incidence, co-occurrence, and evolution of long-COVID features: A 6-month retrospective cohort study of 273,618 survivors of COVID-19, is published in PLOS Medicine after the embargo at: https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003773
Professor Paul Harrison is an honorary consultant psychiatrist in Oxford Health NHS Foundation Trust.
About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the fifth year running, and at the heart of this success is our ground-breaking research and innovation. Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions.
The University Department of Psychiatry’s mission is to conduct world-class research, teach psychiatry to medical students, develop future researchers in a graduate programme, teach doctors in training, promote excellence in clinical practice, and develop and provide innovative clinical services. It supports research in four key areas: neurobiology, psychological treatments, developmental psychiatry and social psychiatry. The Department is committed to the translation of scientific discovery into benefits for patients. www.psych.ox.ac.uk
About the NIHR Oxford Health Biomedical Research Centre
The mission of the National Institute for Health Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:
- Funding high quality, timely research that benefits the NHS, public health and social care;
- Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
- Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
- Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
- Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
- Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.
NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK Aid from the UK government.
TriNetX is a global health research network that connects the world of drug discovery and development from pharmaceutical company to study site, and investigator to patient by sharing real-world data to make clinical and observational research easier and more efficient. TriNetX combines real time access to longitudinal clinical data with state-of-the-art analytics to optimize protocol design and feasibility, site selection, patient recruitment, and enable discoveries through the generation of real-world evidence. The TriNetX platform is HIPAA and GDPR compliant. For more information, visit TriNetX at www.trinetx.com or follow @TriNetX on Twitter.