These sections briefly explain why the committee made the recommendations.


Why we made the recommendations

Case definition

Recommendation 1.1

To effectively diagnose, treat and manage a condition, it needs to be defined and distinguished from other conditions. A set of definitions was needed to distinguish 3 phases following infection consistent with COVID‑19, and to define the term 'long COVID'.

When developing the terms used in this guideline, many different factors were taken into account. The aim was to reduce the existing confusion about how to define the disease for clinical guidance. The panel recognised the significant progress made by patient groups using the term 'long COVID'. However, the term 'long COVID' has been used in multiple ways across the literature. Other terms have also been used. Greenhalgh et al. (2020) uses the terms 'post-acute COVID‑19' (from 3 to 12 weeks) and 'chronic COVID‑19' for symptoms extending beyond 12 weeks. The National Institute for Health Research themed review notes the possibility of a number of different syndromes.

The evidence on and pros and cons of different terms were reviewed. Specific clinical diagnostic criteria were needed to facilitate access to support, provide the basis for planning services and to enable formal codes to be developed for clinical datasets. Three definitions were developed: acute COVID-19 (0 to 4 weeks), ongoing symptomatic COVID‑19 (4 to 12 weeks) and post‑COVID‑19 syndrome (12 weeks or longer).

In deciding these time periods, the panel were aware of evidence showing that most people's symptoms will resolve before 12 weeks from the start of acute COVID‑19, while for a smaller proportion of people they will continue for longer. People may also develop signs or symptoms of a life‑threatening complication at any time and these need to be investigated urgently.

The panel concluded that most people who have symptoms or had a positive COVID‑19 test would no longer be self‑isolating after 4 weeks and could be investigated for ongoing symptomatic COVID‑19 (4 to 12 weeks) with the possibility of later being diagnosed with post‑COVID‑19 syndrome (12 or more weeks).

The cumulative long-term evidence remains inconclusive for the trajectory and duration of the ongoing effects currently seen after a SARS‑CoV‑2 infection. The term 'post' COVID-19 syndrome was agreed to reflect that the acute phase of the illness has ended, not that the person has recovered. Because it is not clear how long symptoms may last, the panel agreed that time-specific terms such as 'chronic' or 'persistent' were not appropriate. 'Syndrome' was agreed to reflect the 'running together' or concurrence of the multisystem, fluctuating and often overlapping 'clusters' of symptoms that people present with.

Advice and written information

Recommendations 1.2 to 1.4

People need good information after acute COVID-19 so they know what to expect and when to ask for more medical advice. This could help to relieve anxiety if people do not recover in the way they expect. Evidence from patient experience and the panel's own experiences supported this, particularly because symptoms can fluctuate and there are so many different symptoms reported. Information may be provided by GPs or community services, or by secondary care for people who were in hospital.

The panel noted that accessibility of information is a legal requirement and is particularly important after acute COVID-19 because people may have cognitive symptoms ('brain fog') or fatigue, making it difficult for them to take in long or complex information.

The panel heard expert testimony that absence from or poor performance at work or education was associated with poor outcomes for people with ongoing symptomatic COVID-19 or post-COVID-19 syndrome. Awareness of this may be helpful to healthcare professionals in identifying people who may need further assessment. The panel agreed that it is important for people to contact a health professional if they are struggling with returning to work or education after acute COVID-19 to ensure they receive support with any continuing symptoms.

The panel discussed whether there were any symptoms in particular that people should look out for that may suggest they have ongoing symptomatic COVID-19 or post-COVID-19 syndrome. The panel agreed that people should contact a healthcare professional if they are concerned about any new, ongoing or worsening symptoms. The panel also noted that there is some helpful information available such as the Your COVID Recovery website that outlines when people should contact their healthcare professional.

Observational evidence and expert testimony on the safety and therapeutic benefit of COVID-19 vaccines in the context of treating long-term effects of COVID-19 (see evidence review K: impact of vaccines) were inconclusive for the outcomes of duration and change in symptoms, quality of life and mental wellbeing. The population included people with existing long-term effects of COVID-19 and people infected after vaccination who reported symptoms of 28 days or longer since vaccination.

The expert panel agreed that the findings could not justify a positive recommendation for COVID-19 vaccination to treat the long-term effects of COVID‑19, nor a negative recommendation against this intervention in the absence of evidence of harm.

However, the panel recognised the safety and effectiveness of vaccines in preventing acute infection and the importance of the national COVID-19 vaccination programme to protect all people, particularly those who are at highest risk from serious illness or death from COVID-19 or at risk of transmitting infection. Therefore, the panel emphasised the need to encourage patients with long-term effects of COVID-19 who have not been vaccinated to have the vaccination to reduce the risk of a further SARS-CoV-2 infection, but to explain the uncertainty about the effect of vaccination on ongoing symptomatic COVID-19 and post-COVID-19 syndrome.

New and ongoing symptoms after acute COVID-19

Recommendations 1.5 to 1.7

Healthcare professionals in all services need to be alert to whether people may need support. Although most people with ongoing symptoms will start to improve between 4 and 12 weeks, some will need further investigation and others will need rehabilitation to help them recover. The panel therefore agreed that ongoing symptomatic COVID-19 and post-COVID-19 syndrome should be considered as part of the differential diagnosis at 4 to 12 weeks and beyond 12 weeks, respectively. The panel also emphasised that this applies to children and young people as well as adults.

In the panel's experience, some people, including children and older people, may report different symptoms from those most commonly seen in the adult population. The panel highlighted this to make sure their needs are still identified. For example, the panel did note that some cardiac and respiratory symptoms were less commonly reported in children than adults and agreed that these symptoms should be noted to inform investigation of alternative diagnoses.

The expert panel agreed that an initial consultation would help identify people who need further assessment. A detailed discussion between the person and a healthcare professional is an important part of understanding their symptoms, and the way in which the symptoms affect their daily life. This discussion will form the first part of an assessment, and inform decisions about whether further assessment and investigations are needed (see section 2 on assessment). The panel also agreed that the format of the consultation should be discussed and agreed with the person according to their needs and preferences and local availability of services.

Some screening questionnaires are being used in practice to capture a person's symptoms, but none are fully validated for this use. Questionnaires can be useful in preparation for or during the initial consultation but the panel did not want them to be used on their own to decide if further assessment is needed. Examples of questionnaires include the COVID-19 Yorkshire rehabilitation questionnaire, recommended by NHS England, and the modified International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) global paediatric COVID-19 follow-up questionnaire. Questionnaires should ideally be developed in partnership with patients and be fully validated.

Need for further assessment

Recommendations 1.8 and 1.9

There was evidence supporting further assessment in person after the initial consultation and the panel agreed this was important to fully assess people who need it. A consultation in person might not be suitable for everyone, so this should be agreed as a shared decision. However, the panel agreed that decisions about whether consultations should be remote or in person should always take into account any safeguarding concerns.

The panel agreed on the need to address health inequalities in care for people after acute COVID-19. Some people are less likely to seek help for symptoms or may be at risk of not being followed up after hospital care, for example, because of language barriers, mental health conditions, mobility or sensory impairments, learning disabilities or cultural differences in seeking help. Providing extra support and raising awareness could improve access to care.

Proactive follow-up after acute COVID-19

Recommendations 1.10 and 1.11

The panel agreed, based on expert testimony and their experience, that proactive follow‑up of people from underserved or vulnerable groups who are known to have had acute COVID-19 in the community could improve access to care and identify people who could be at increased risk of complications.

The panel recommended active follow‑up at 6 weeks to help identify if people are still struggling with symptoms. It may not be needed for all patients, but it would be backed up by the information about self-referring for reassessment if people felt their health was not improving. The panel agreed that this consultation can be in person or remote.

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Recommendations 2.1 to 2.6

Why we made the recommendations

The evidence suggested that healthcare professionals should use a holistic approach to assessment and the panel agreed that assessment should cover both symptoms and how they affect the person overall. Evidence from patient experience showed that many people feel their symptoms are not taken seriously. There are also people who do not realise that their symptoms are connected with COVID‑19, so taking time to listen, showing empathy, taking a careful history and making an assessment are important.

The panel noted that the evidence and patient experience showed that symptoms can fluctuate and healthcare professionals should be aware of this when carrying out a holistic assessment. Some people may need help to describe their symptoms, including those who experience cognitive symptoms, such as 'brain fog', confusion and loss of memory, after acute COVID-19. The panel highlighted the value of talking to family members or carers, with the person's agreement, to help get a full clinical picture for people who need extra support with communication.

There were too many uncertainties in the evidence to provide any symptoms that could predict whether people might develop post-COVID-19 syndrome. The panel also did not want healthcare professionals to assume that people who had been hospitalised were more likely to develop post-COVID-19 syndrome because the current evidence and the panel's own experience do not support this.

The panel discussed and agreed that healthcare professionals should be aware that older people may not present with the common symptoms associated with ongoing symptomatic COVID-19 or post-COVID-19 syndrome. The panel agreed on signs that might prompt a healthcare professional to consider ongoing symptomatic COVID-19 or post-COVID-19 syndrome alongside other possible causes in an older person.

Many people experience cognitive symptoms, such as 'brain fog', confusion and loss of memory. The panel agreed that validated screening tools are useful for measuring and monitoring any impairment and the impact of this. The panel were aware of several tools but were unable to recommend any specifically because the evidence was not reviewed. They also agreed that the type of tool will differ depending on the setting and level of assessment needed.

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Investigations and referral

Recommendations 3.1 to 3.12

Why we made the recommendations

Investigations are important to identify symptoms that could be caused by an acute or life-threatening complication, and to assess for other underlying conditions and complications.

For signs and symptoms to help identify paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS), see the guidance on PIMS from the Royal College of Paediatrics and Child Health.

The panel agreed that no one set of investigations and tests would be suitable for everyone because of the wide range of symptoms and severity. Investigations need to be tailored to the person's signs and symptoms and whether they are being assessed in primary care (blood tests, the 1‑minute sit‑to‑stand test) or secondary care (exercise tolerance tests). They agreed that blood tests and exercise tolerance tests (if safe and appropriate for the person) would be useful for most people as investigations and baseline measures. These were also the tests most commonly reported in the evidence, along with chest X-rays.

The panel agreed that when carrying out investigations for ongoing symptoms following acute COVID-19, it is important that other potential diagnoses are not ignored. Healthcare professionals should follow relevant clinical guidance if a diagnosis unrelated to COVID-19 is suspected.

The panel suggested some blood tests, such as a full blood count and kidney, liver and thyroid function tests, that are commonly carried out to help rule out or confirm other conditions.

The panel agreed that blood tests should only be offered if clinically indicated. They discussed that tests should be carried out as needed when an alternative diagnosis is suspected. However, they recognised that multiple tests can be a negative experience for some people and may not always be needed to inform management of the person's symptoms. They agreed that testing should be guided by the person's symptoms and used to supplement a detailed holistic assessment.

In the panel's experience, self-monitoring at home can be useful and is used in practice. But it might not be suitable for everyone, and without the right information and support can cause unnecessary anxiety. People need good guidance to use equipment, interpret the results and understand when to contact a healthcare professional. The panel agreed that this advice also applies to parents or carers monitoring children at home.

The panel discussed the usefulness of carrying out a sit‑to‑stand test but also agreed clinical judgement would be needed because it is not suitable for everyone (for example, people with chest pain or severe fatigue). They agreed skill sharing between services could help with gaps in knowledge and that a protocol should be followed in order to carry a sit‑to‑stand test out safely. The panel discussed that appropriate protocols could be found in these studies: Ozalevli S, Ozden A, and Akkoclu A (2007) Comparison of the sit-to-stand test with 6 min walk test in patients with chronic obstructive pulmonary disease and Briand J, Behal H, Chenivesse C et al. (2018) The 1-minute sit-to-stand test to detect exercise-induced oxygen desaturation in patients with interstitial lung disease. The panel could not recommend any one in particular as their effectiveness is undetermined.

Postural symptoms are common, so the panel agreed that these should be investigated by taking lying and standing blood pressure and heart rate. Advice on carrying this out is available from the Royal College of Physicians' brief guide on measuring lying and standing blood pressure.

The evidence suggested that not all pathology shows up on a chest X-ray so the panel agreed it should only be used as part of a holistic assessment to decide if referral or further care are needed in people with respiratory symptoms. The panel agreed that a chest X-ray should not be carried out if the person has already had one and there have been no subsequent clinical changes.

Evidence and expert testimonies from the Royal College of Psychiatry 2020 and Nicol 2021 (see evidence review E: monitoring and referral and supporting document 2: expert testimony for rehabilitation) highlighted that mental health symptoms are common after acute COVID‑19. The committee agreed that it is important that people with severe psychiatric symptoms or at risk of harm are identified during assessment and urgently referred for psychiatric assessment and support in line with relevant guidance (see the Royal College of Psychiatrists' position statement [2019] on the role of liaison psychiatry in integrated physical and mental healthcare).

Evidence suggested that many people struggle to adjust to changes in their life, abilities and self-identity and reported feelings of helplessness and isolation. This was also supported by expert testimony, which suggested that symptoms of low mood and anxiety are common. The panel agreed that when mental health symptoms are identified during assessment, people need to be referred for support in line with relevant guidance (see the Royal College of Psychiatrists' position statement [2019] on the role of liaison psychiatry in integrated physical and mental healthcare).

For many people with ongoing symptomatic COVID‑19 or post‑COVID‑19 syndrome, this will mean referral to an integrated multidisciplinary assessment clinic for investigation, support to manage their symptoms and rehabilitation. Prompt referral is needed to avoid delays in getting people the support they need. In the panel's experience, the earlier people received help, the more effective the interventions. The panel were also concerned that a lack of support could negatively affect people's mental health. They agreed that referral should be offered to those who would benefit from these services from 4 weeks after the start of acute COVID‑19.

The panel discussed expert testimony from Locke 2021 (see supporting document 2: expert testimony for rehabilitation), which reported that in some areas of the UK, provision of an integrated multidisciplinary assessment service is not feasible. The recommendation was updated to take into account that people may be referred to other appropriate services. Different service pathways are in place across the UK, and this guideline is not intended to cover the diagnostic or management approaches delivered by the more specialist services involved in caring for patients with persistent symptoms or complications after acute COVID-19, such as post-COVID assessment services in England or specialist clinics.

The patient experience evidence described how some people were not offered tests and other people were refused a referral by healthcare professionals because they did not have a positive SARS‑CoV‑2 test result. Many people who had acute COVID‑19 were not tested, particularly earlier in the pandemic. The panel were clear that access to services should not be restricted by the need for a positive SARS‑CoV‑2 test (PCR, antigen or antibody) if the case definition criteria in section 1 on identification are met.

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Planning care

Recommendations 4.1 to 4.3

Why we made the recommendations

To ensure people get the right care and support, the expert panel agreed that a tiered approach could be used in which everyone gets advice for self‑management, with the additional option of supported self‑management if needed. People can then also be offered care from different services to match the level of their needs. The recommendation applies to all age groups and allows for discussion with the family or carers of the person if appropriate.

There was not enough evidence to recommend specific criteria for referral and the panel agreed the right level of care would be agreed in shared decision making with the person after their holistic assessment.

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Self-management and supported self-management

Recommendations 5.1.1 to 5.1.3

Why we made the recommendations

There was very little evidence on interventions such as specific pharmacological treatments for ongoing symptomatic COVID-19 or post-COVID-19 syndrome, but the panel agreed that everyone should have self‑management support and information. There was a lack of COVID‑19‑specific evidence on managing many of the common symptoms related to COVID‑19, such as fatigue, dizziness and cognitive problems (such as 'brain fog'). However, there are established treatments for managing individual common symptoms. For example, antihistamines can be used to treat some skin rashes. The panel noted that, given the fluctuating nature of the symptoms, regular review and monitoring is needed for people receiving any form of treatment.

NICE will continue to monitor and review new evidence in this area as part of its living approach to maintaining the guideline.

Patient organisations and online support groups can help to support self‑management. The Your COVID recovery website was also highlighted as a potential source of reliable, up‑to‑date information and support.

The panel were concerned that people are buying over-the-counter vitamins and supplements that may not help with their symptoms. They agreed that it would be helpful to highlight the lack of knowledge in this area.

The panel agreed that support to return to education or work, such as setting achievable goals, should be tailored to the person's needs. This might involve support to work or study at home, flexible working or a phased return.

For the November 2021 update, the panel heard expert testimonies from Stark 2021 and Whittaker 2021 (see evidence review J: children and young people) describing that absence from or poor performance in education was associated with poor outcomes for children and young people with ongoing symptomatic COVID‑19 or post-COVID-19 syndrome. The panel agreed that this would also apply to adults returning to work or education. Healthcare professionals should be aware that people who are struggling to return to work or education may have symptoms that persist for longer than other people and may need additional support.

Further advice on returning to work can be found in the Society for Occupational Health Medicine guidance on COVID-19 return to work guide for recovering workers and COVID-19 return to work guide for managers.

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Multidisciplinary rehabilitation

Recommendations 5.2.1 to 5.2.4

Why we made the recommendations

The panel agreed that multidisciplinary rehabilitation teams should work with people to make a plan for their rehabilitation once any symptoms had been investigated that could affect the safety of rehabilitation. Physical, psychological and psychiatric aspects of rehabilitation should be addressed, with fatigue management being a key component of this. The evidence showed that breathlessness, fatigue and 'brain fog' are among the most commonly reported long‑term symptoms, so support for these should be part of the person's rehabilitation plan.

A personalised rehabilitation and management plan records the person's needs and how they will be met. In some settings a 'rehabilitation prescription' may be used to capture this information. The rehabilitation prescription is held by the person and includes an individualised description of rehabilitation needs or recommendations to inform the future planning and delivery of a person's ongoing rehabilitation. The panel recognised that some people may need additional support, such as an interpreter or advocate, in developing the rehabilitation and management plan.

The evidence highlighted the fluctuating nature of ongoing symptomatic COVID-19 and post-COVID-19 syndrome. Based on this evidence, the panel agreed that it was key that a management plan should take into account that symptoms may fluctuate.

Based on their experience, the panel agreed on the value of symptom diaries and symptom tracking apps in self-monitoring. The evidence for different symptom tracking apps was not reviewed so the panel could not recommend a specific product.

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Additional support

Recommendations 5.3.1 and 5.3.2

Why we made the recommendations

There was a lack of evidence for specific age groups on managing ongoing symptomatic COVID‑19 or post‑COVID‑19 syndrome. Based on their clinical experience, the panel made a recommendation for older people and other groups such as people with complex needs who may be vulnerable to ensure that they receive additional care and support, if needed, that is tailored to the particular needs of this population.

There was a lack of evidence on managing ongoing symptomatic COVID‑19 or post‑COVID‑19 syndrome in children and young people. Based on their experience, the panel agreed that referral should be considered so that children and young people can be supported to manage their symptoms early and recover quickly. The recommendation covers all children and young people, including those aged 16 to 18 who should be supported to access specialist advice through either adult or paediatric services depending on local referral pathways.

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Follow‑up, monitoring and discharge

Recommendations 6.1 to 6.3

Why we made the recommendations

There was a lack of evidence on monitoring, but the panel agreed it is important so that people's support can be adapted if their symptoms or ability to carry out their usual activities change. The patient experience evidence highlighted the importance of follow-up and 'check-ins' to access further care. The panel did not want to limit monitoring to specific tests or symptoms, or to a particular timeframe, because people with ongoing symptomatic COVID‑19 and post‑COVID‑19 syndrome have such a wide range of care needs. They decided it should be tailored to each person's needs and preferences.

The evidence on when to refer was limited and based mostly on people who had been hospitalised, so it was not relevant to everyone. The panel agreed that healthcare professionals should be alert to any changes and that the recommendations in the assessment section would also apply to monitoring.

The panel discussed when a person should be discharged from rehabilitation and care. They agreed that a timepoint could not be specified, because this is dependent on the person's symptoms, the goals that were set, the progress made and the amount of social support the person has. However, they agreed that making a discharge plan with the person would support motivation, ensure the person gets the support they need and help to manage rehabilitation resources. The panel also agreed that transition to adult services should be considered in discharge planning for young people.

Expert testimony highlighted the importance of people being able to re-enter rehabilitation services after being discharged if their symptoms worsen. The panel recognised that symptoms may fluctuate and recur with patients needing to re-access support and services in the most efficient way possible. However, following shared decision making, local referral pathways would need to be followed because of variation in practice and funding.

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Sharing information and continuity of care

Recommendations 7.1 to 7.4

Why we made the recommendations

There was evidence that people struggled to access appropriate care and some had experienced fragmented care. The panel agreed on the need to improve integration and coordination of care across different services. Having regular multidisciplinary meetings would help share information more efficiently and allow professionals to make decisions quickly about tests and referral.

The panel wanted to make sure that information is also shared with people using services so that they know what is happening with their care.

Sharing clinical records and care plans between services, with the agreement of the person, will help healthcare professionals provide integrated care, and avoid gaps in care or duplication of effort. In particular, sharing baseline measures is essential for monitoring as people move between services.

The patient experience evidence described how people could benefit from continuity of care, and the panel agreed this should always be an aim for well-integrated services.

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Service organisation

Recommendations 8.1 to 8.4

Why we made the recommendations

Different regional and geographical challenges mean that areas have different service needs and resources, so the panel agreed that 1 model would not fit all areas. The panel agreed a multidisciplinary service for assessment could avoid multiple referrals and would provide a single point for care. This could be a 'one-stop' clinic to help keep appointments to a minimum, although this might not be feasible for all services or wanted by all patients. In areas where multidisciplinary services are not available, services may be provided through integrated and coordinated primary care, community, rehabilitation and mental health services.

The limited evidence described different models of rehabilitation services. The panel agreed that some of the common elements, such as integration and multidisciplinary team working, would help provide effective, well-organised care for people with ongoing symptomatic COVID‑19 and post‑COVID‑19 syndrome. The panel considered examples of a core team could include occupational therapy, physiotherapy, clinical psychology and psychiatry and rehabilitation medicine.

Because symptoms are so wide-ranging, many other areas of expertise could also be added as needed. This could include, but are not limited to, rheumatology, neurology rehabilitation, cardiology, paediatrics, dietetics, speech and language therapy, nursing, pharmacy, social care and support to return to education or work or usual activities.

Based on their experience, the panel wanted to encourage different services to share knowledge and expertise with each other, to help expand the choice of tests and interventions available in the community. This could be done through local clinical networks or clinical hubs.

As well as ensuring the right breadth of expertise, having a multidisciplinary team with input from other services and clear referral pathways can prevent disjointed care and people waiting a long time for appointments with multiple specialists. This was supported by the patient experience evidence, which described the challenges of attending multiple appointments and repeated investigations.

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Common symptoms

Recommendations in the box

Why we made the recommendations

There are signs and symptoms that were consistently identified in the evidence and the panel agreed that it would be useful to provide common symptoms list. The panel also discussed that symptoms such as menstrual symptoms and 'COVID toes' are common in their experience, but noted that they were not identified in the evidence and so were not added to the common symptoms list. It was further noted that adjustment disorder was highlighted as a symptom in the patient experience review; however, this too was not commonly reported in other studies so was not added to the common symptoms list.

Expert testimonies from Stephenson 2021 and Whittaker 2021 (see evidence review J: children and young people) and evidence on signs and symptoms in children and young people indicated that cardiac and respiratory symptoms are less common in young people. The panel agreed that it is important to highlight the specific symptoms identified as less common in this population.

The panel noted that people typically experience a constellation of symptoms and the presence of an isolated symptom should prompt thorough consideration of other possible causes.

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