New tool provides insights into Long COVID syndrome symptoms

long COVID syndrome
© iStock/AnnaStills

With over 200 symptoms associated with long COVID syndrome, we spoke to Dr Sarah Hughes from the University of Birmingham about the significance of a new tool that can measure symptom burden and support researchers and healthcare providers in their understanding of the condition.

Long COVID syndrome is thought to affect around 1.3 million people in the UK alone and incurs a range of symptoms that can last months after the initial infection has gone. The breadth and varying severity of symptoms as well as a lack of robust research around long COVID has made diagnosing and treating the condition very difficult. Now a team based at the University of Birmingham’s Centre for Patient-Reported Outcomes Research have developed a Symptom Burden Questionnaire™ alongside patients that have lived experience of long COVID which they hope can be used to inform future tests and therapies for the condition. The comprehensive questionnaire enables sufferers to report their symptoms and the impact these are having on their everyday life. To discuss what the SBQ-LC system entails and how this could be used in clinical practice in the future, Health Europa Quarterly spoke with Dr Sarah Hughes from the university’s Institute of Applied Health Research.

How much is known about the causes and symptoms of long COVID? Can you highlight some of the ways in which long COVID can impact a person’s everyday life?

We now know that long COVID syndrome involves many heterogeneous symptoms that can fluctuate over time. There is evidence to suggest that long COVID is not linked to the severity of acute COVID-19 infection and that long COVID can develop in individuals who experience only mild infection. It is also likely long COVID is several conditions characterised by different symptom clusters, rather than a single condition. Researchers around the world are working to understand these various symptom clusters, the clinical course, and the underlying biological mechanisms that drive long COVID. For example, the UK’s National Institute for Health and Care Research/UK Research and Innovation-funded Therapies for Long COVID in non-hospitalised individuals (TLC) Study will use symptom data collected using the SBQ-LC and other questionnaires (delivered through a digital platform developed by Aparito Ltd), wearable data, and blood and other biological tests to characterise and immunologically phenotype long COVID syndromes.

Long COVID can have a significant, ongoing impact on a person’s quality of life, mental health, and employment. Long COVID can impact individual’s ability to do even simple everyday activities such as bathing, dressing, shopping, and housework. It can affect people’s ability to go to work and hold down employment. Patient advocacy groups have called on governments to recognise long COVID as a disability and an occupational disease.

Patient advocacy groups have called on governments to recognise long COVID as a disability and an occupational disease © iStock/shironosov

Why was it important to develop the SBQ-LC? What does the SBQ-LC hope to uncover or understand?

It was important to develop the SBQ-LC to provide healthcare professionals and long COVID syndrome researchers with a tool to measure long COVID symptom burden from the patient perspective. Reliable and valid patient-reported symptom data are needed urgently to inform diagnosis, support care, and evaluate the safety and effectiveness of treatments in clinical trials. However, given the novelty of long COVID, measures developed specifically for long COVID are currently limited. When we shared existing symptom questionnaires with patients, they told us that the questionnaires did not represent their lived experience. Therefore, we decided to develop the Symptom Burden Questionnaire for long COVID as part of the TLC Study. We drew upon the expertise of TLC study team members based at the Centre for Patient Reported Outcome Research (CPROR) at the University of Birmingham and worked in partnership with patients to develop the SBQ-LC.

The SBQ-LC provides coverage of all clinical symptoms/life impact domains specified in the NHIR-funded post-COVID-condition Core Outcome Set endorsed by the World Health Organization and we hope it will be widely adopted to enable comparative global data. We hope the SBQ-LC will contribute high-quality, patient-reported symptom data that researchers can use to describe long COVID phenotypes, conduct research into underlying causes of long COVID, develop our understanding of clinical course of the condition, evaluate treatments, and deliver better care to help the millions of people suffering the effects of this debilitating condition.

Can you give an overview of what the SBQ-LC comprises to measure an individual’s long COVID symptom burden?

The SBQ-LC has 16 independent scales measuring over 100 symptoms of long COVID syndrome. Each scale measures a different symptom domain. The scales include breathing, circulation, pain, fatigue, memory, thinking and communication, movement, sleep, ear, nose and throat symptoms, vision, stomach and digestion, muscles and joints, mental health and wellbeing, skin and hair, reproductive and sexual health (male and female scales), and other symptoms. There is also an interference scale measuring the impact of a person’s symptoms on everyday life. Researchers and clinicians who wish to use the SBQ-LC can request a license and then may select specific scales or administer the full instrument for a comprehensive overview of a person’s symptoms.

Did you observe any significant limitations or challenges during the creation of the SBQ-LC?

Long COVID covers a wide range of, often fluctuating, symptoms that can appear at any time following the initial COVID-19 infection. Researchers do not yet know what long COVID syndrome actually ‘is’ and therefore what symptoms should be measured.  The novelty of long COVID posed a challenge for the research team as we needed to construct a questionnaire that comprehensively covered the large number of long COVID symptoms while not being burdensome for individuals to complete. We worked closely with our patient partners and member of the TLC Study’s Patient and Public Involvement Group to ensure the SBQ-LC’s questions were relevant, easy to understand and captured what mattered most to people living with long COVID.

What are your goals for the SBQ-LC in terms of its wider use in clinical settings?

The SBQ-LC has several potential uses in routine clinical settings.  If presented to patients using an app on a smart phone or tablet, the SBQ-LC can be used to collect symptom data in real-time without the need for patients to visit their clinic, hospital, or surgery. Using the SBQ-LC remotely for ongoing symptom monitoring can help to ensure care is safe, timely, and effective. The system has the potential to generate alerts and trigger notifications to a person’s healthcare team if they report symptoms of clinical concern.  Collecting symptom data using the SBQ-LC can provide patients with a record of their symptoms to support self-management of their condition. A record of long COVID symptoms is especially helpful because of the large number of fluctuating symptoms that patients experience. The SBQ-LC can be used to support conversations between patients and their healthcare team to inform decision-making around treatment, measure the outcomes of intervention, and support onward referrals. Ultimately, we are keen to see the SBQ-LC used in clinical settings to support and manage patients with long COVID to improve clinical outcomes.

The SBQ-LC is available for use by researchers and clinicians upon completion of a license agreement (

Funding statement

This work is independent research jointly funded by the National Institute for Health and Care Research (NIHR) and UK Research and Innovation (UKRI) (Therapies for Long COVID in non-hospitalised individuals: From symptoms, patient reported outcomes and immunology to targeted therapies (TLC Study), COV-LT-0013). The views expressed in this publication are those of the author(s) and not necessarily those of NIHR, The Department of Health and Social Care, or UKRI.

Dr Sarah Hughes BSc, MHSc, PhD, MRCSLT
Institute of Applied Health Research Fellow
University of Birmingham

This article is from issue 22 of Health Europa Quarterly. Click here to get your free subscription today.


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