UK experts call for a refined, universal definition of long COVID

Two leading UK experts in infectious diseases who played a major research role during the pandemic have called for a refined, universal definition of long COVID. They say this will mean identification and treatment of patients can be improved, and estimates of the burden of long COVID can be combined from different studies. 

Dr Daniel Pan, and Professor Manish Pareek, from the University of Leicester, first identified that a higher risk of infection was driving disproportionate clinical outcomes - such as hospitalisation, intensive care admission and death - in ethnic minority groups compared to majority groups across the world. This work was featured by international news outlets and in the House of Commons. Prof Pareek was awarded the Graham Bull Prize from the Royal College of Physicians for making a major contribution to clinical science.

Now, in an invited editorial published by JAMA Network Open, Dr Pan and Prof Pareek argue for the need for a universal definition for long COVID. This was written in response to a new study published in the journal, which found that definitions vary in published scientific literature, and many do not match those used in definitions provide by the National Institute for Health and Care Excellence (NICE), World Health Organisation (WHO) and the Centres for Disease Control and Prevention (CDC ). Furthermore, these three organisations provided separate definitions of long COVID themselves. Dr Pan and Prof Pareek also mention that the name of long COVID can be different according to different organisations (such as post-COVID-19 condition) which can be confusing for everyone, especially patients.

Dr Pan said: “The lack of a consistent definition for long COVID between both organisations and studies makes assimilating, and comparing, findings from current studies difficult. Any estimated prevalence or incidence of long COVID will vary widely between studies, even if conducted in the same time period, in the same population.”

Prof Pareek said: “It is likely that current estimates are underestimating the true burden of those with long COVID, due to this issue. Only once the natural history of long COVID is better defined, can we have a more personalised and effective approach to the treatment of those affected.”

The Leicester experts propose a refined definition for long COVID that could be adopted by all organisations and studies. A possible definition could be: ‘signs and symptoms following initial SARS-CoV-2 infection, that persist for more than one month (in mild cases), and more than three months (in cases severe enough to warrant oxygen support), which have a disproportionately severe effect on a patient’s quality of life, far beyond what is expected from their initial infection.’ This definition will need further refinement over time, with particular engagement from patients themselves, who originally invented the term long COVID.