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Study identifies the best way to measure improvement in Long COVID

Published: 03 November 2023

A NIHR-funded study has reached an agreement amongst researchers and patients on how best to measure improvement in Long COVID.

Researchers have identified a Core Outcome Measure Set (COMS). This is designed to help researchers and clinicians measure the severity and impact of Long COVID. COMS specify key things that should be measured in all patients. This improves how data can be compared and summarised.  Researchers say this will speed up the development of treatments for Long COVID. 

The research is published in Lancet Respiratory Medicine. It was co-led by the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London and in collaboration with the World Health Organisation (WHO). The research included close collaboration with Long Covid patients and organisations.

Symptoms that persist or develop after COVID-19 are known as Long COVID.  They are also described by other names such as Post COVID-19 Condition, Post Acute Sequelae of COVID-19 (PASC) or Post-COVID Syndrome. Common symptoms include:

  • fatigue
  • shortness of breath
  • pain
  • exercise intolerance
  • cognitive dysfunction (brain fog)

But, patients can experience a wide range of other symptoms across all bodily systems. This makes it hard to identify the key symptoms and decide how to measure them. The COMS agreed in this study will help solve this challenge. 

Previously the research team conducted a consensus study that led to the development of a 12-item core outcome set (COS). These are 12 aspects of Long COVID that should be measured in all studies and clinical services worldwide. These findings were published in the Lancet Respiratory Medicine in early 2023.

This study was able to reduce the number of potential instruments for measuring those 12 core outcomes from 319 to 19. The final COMS included the measurement instruments for 3 of the 12 outcomes: survival; recovery; and respiratory functioning, symptoms, and conditions. These instruments are now being recommended for use in clinical and research settings for adults with Long COVID. Although an agreement was not reached for any single instrument for the remaining 9 core outcomes, the instruments with the greatest level of support are being recommended for considered use.

The Delphi technique

The study involved identifying the ways in which Long COVID symptoms and impact have been measured to date. The most popular ones that could be used in all settings were presented to an international group of experts and patients in a series of surveys. A final ‘consensus meeting’ aimed to reach an agreement on the best measurement instrument(s) for the 12-item COS. The surveys used a ‘Delphi technique’ to reach consensus among the stakeholders. This is an approach where participants are asked their opinions in a first round, shown the results of others and then given the chance to rethink their views. This is repeated in later rounds until consensus is achieved.

Capturing lived experience

Dr Tim Nicholson, a Reader in Neuropsychiatry and one of the study’s co-leads from King’s IoPPN said, “The development of this Core Outcome Measure Set for Long COVID by the global research community in partnership with patients with lived experience has set out a key plank in the development of evidence-based treatments for this new condition to allow the optimisation, coordination and efficient collation of data in research and clinical services.”

Professor Nick Lemoine, Medical Director at the NIHR Clinical Research Network said, "This NIHR-funded research is taking us a step closer to having a clear and consistent way to measure the impact of long COVID - this is a vital tool to help speed up research to find the most effective treatments. Researchers and patients have worked closely together to agree on measures that encompass people's lived experience of Long COVID."

Dr Margaret O’Hara, from Long COVID Support said, “People with Long COVID, from Long COVID Support and other groups, have been involved in all stages of the design and implementation of this study. It is important to us because we need research to measure symptoms that are relevant, and to use measurement tools that can capture our actual experience. We also need researchers around the world to use the same instruments so that studies can be compared and we can rapidly build a body of evidence to assess if treatments work. The clock is ticking for people with Long COVID, we urgently need treatments and we will only get them through research. This study will help to quicken the pace at which evidence can be gathered.”

The researchers are now seeking to publicise these recommendations so that they are adopted by the scientific and clinical communities. Further work is also planned to update the COMS as new data on Long COVID emerges and how best to measure its improvement.

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