Living Evidence - post acute sequelae of COVID-19 (long COVID)

Living evidence tables provide high level summaries of key studies and evidence on a particular topic, and links to sources. They are reviewed regularly and updated as new evidence and information is published.

The World Health Organization defines post acute sequelae of COVID-19 (long COVID) as “[a] condition that occurs in individuals with a history of probable or confirmed SARS CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms and that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, cognitive dysfunction but also others and generally have an impact on everyday functioning. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate or relapse over time." Research definitions of Long COVID has been developed through a Delphi process for adults and for children.

The World Health Organization estimates that approximately 10% to 20% of people experience a variety of mid- and long-term effects after they recover from their initial illness. Recent prevalence estimates suggest that between 3.69 and 20% of individuals who experience COVID-19 infection develop long COVID.  A large-scale study of self-reported data found that long COVID rates are lower (4.5%) for Omicron than for Delta (10.8%). However, definitions of long COVID are varied and prevalence studies often rely on self-reported symptoms and diagnosis.

In a clinical setting, there is no definitive test for long COVID, and diagnosis is based on ruling out other similar conditions.

Risk factors for long COVID include: number of initial COVID-19 symptoms, being female, being older,  living in more deprived areas, working in social care, teaching and education or health care, and having another activity-limiting health condition or disability.

Protective factors for long COVID include vaccination and young age.

Based on data from the Office for National Statistics in the United Kingdom, prevalence appears higher for Delta than Omicron BA.1 in double vaccinated individuals (15.9% vs 8.7%), and higher for the Omicron BA.2 variant than the BA.1 variant in triple vaccinated individuals (9.3% vs 7.8%).

Various models of care and clinical guidelines have been developed, however, the evidence-base for these is low quality and is continually evolving. There is emerging evidence on developing a framework for a coordinated national health policy action and response and research priorities for long COVID.

This table includes information on ongoing symptomatic COVID-19 and long COVID. It focuses on symptoms, assessment and management.

Checks for new content are conducted regularly.

Time periodSymptomsAssessmentManagement

One month

Symptoms

Reported symptoms include:

Guidance on assessment for long COVID has been published by the Australian National COVID-19 Clinical Evidence Taskforce, the National Institute for Health and Care Excellence (NICE), UpToDate and the US Centers for Disease Control and Prevention.

Generally, assessment recommendations included in these guidelines and the literature include:

Assessment is recommended approximately one week following discharge from hospital for a patient with more severe COVID-19 requiring hospitalisation.

The World Health Organization case report form for COVID-19 sequelae is a clinical tool for documenting mid- and long-term sequelae. The form is recommended to be completed 4-8 weeks after hospital discharge after acute illness and every 3-6 months thereafter.

Guidance on management for long COVID has been published by the Australian National COVID-19 Clinical Evidence Taskforce, the National Institute for Health and Care Excellence (NICE), UpToDate and the US Centers for Disease Control and Prevention.

Management of these conditions is not well defined and is generally based on the management of symptoms following similar illnesses.

The UK maintains a living guideline on managing the long-term effects of COVID-19.

Generally, management and support recommendations included in these guidelines and the literature include:

A Delphi study was conducted to provide a rapid expert guide for GPs and long COVID clinical services in the UK. There were 16 recommendations for management including that individualised rehabilitation, careful activity pacing (to avoid relapse) and multidisciplinary support.

A rapid systematic review of care models for long COVID reports care pathways integrating primary care, rehabilitation services and specialised clinics for medical assessment.^

Generally, symptom management recommendations include:

  • Cough is managed in a similar fashion to cough in patients with post-viral cough syndrome and typically comprises over-the-counter cough suppressants.
  • Self-monitoring of oxygen saturations using a pulse oximeter may be useful in assessment of persistent dyspnea.
  • For people with olfactory and gustatory symptoms, symptoms usually resolve slowly over several weeks and do not require intervention. There is a Cochrane living systematic review on the efficacy of interventions for persistent olfactory dysfunction. Where symptoms persist past two weeks patients may benefit from olfactory training and a limited intranasal or oral corticosteroid course.
  • People with a need for rehabilitation services are typically referred within 30 days of recovery from initial infection. Rehabilitation programs generally last 6-8 weeks, and may include inpatient, outpatient, in-person, web-based or home rehabilitation.
  • Patients diagnosed with documented thromboses are managed in a similar way to thrombosis in non-COVID patients. Direct oral anticoagulants and low-molecular-weight heparin are preferred anticoagulation agents over vitamin K antagonists.
  • Extended thromboprophylaxis considered for high-risk survivors.
  • Patients with pre-existing diabetes mellitus are recommended to ensure optimum glycemic control in the post-COVID-19 period.

The US National Institutes of Health launched RECOVER, a research initiative that seeks to understand, prevent, and treat PASC, including long COVID.

Three months

Symptoms

Reported symptoms include:

Generally, assessment recommendations include:

Generally, symptom management recommendations include:

Six months

Symptoms

Reported symptoms include:

Generally, assessment recommendations include:

Generally, management recommendations include:

Generally, symptom management recommendations include:

  • Management for fatigue, dyspnea and neurologic complications is similar to that in non-COVID-19 patients.
  • Tailored rehabilitation including light aerobic exercises and breathing exercises.  Pharmaceutical treatments including paracetamol and non-steroidal anti-inflammatory drugs may be used to manage specific symptoms e.g. fever.
  • Studies suggest screening and follow up algorithm for patients 4-6 months after COVID-19 with an ambulatory multidisciplinary consultation or specialised post-COVID units.
  • A review study suggests screening for new-onset diabetes mellitus for those aged<70 and that required ICU admission for COVID-19. Routine screening is not recommended for thyroid dysfunction, hypocalcaemia and pituitary apoplexy and male hypogonadism follow up may be undertaken as per clinical context.

12 months

Symptoms

Frequently reported symptoms include:

    Generally, assessment recommendations include:

    • A US-based observational study found an increased relative risk of incidents of cardiovascular disease one month to one year following COVID-19 diagnosis compared to those who have not had COVID-19. Care pathways following an acute episode of COVID-19 are recommended to include attention to cardiovascular health and disease.
    • A learning health system approach is suggested to develop effective, evidence-based therapies for prevention and management of long COVID.

    More than 100 persistent symptoms of COVID-19 have been reported in the literature. Only commonly reported and emerging symptoms have been included in the living table.

    Notes

    * Preliminary data, not fully established, in some cases small numbers or short follow up; interpret with caution

    ^ Commentary, grey literature, pre peer review or news

    The "last updated" date refers to the date when the evidence was last reviewed.

    Living evidence tables include some links to low quality sources and an assessment of the original source has not been undertaken. Sources are monitored regularly but due to rapidly emerging information, tables may not always reflect the most current evidence. The tables are not peer reviewed, and inclusion does not imply official recommendation nor endorsement of NSW Health.

    Last updated on 24 Jun 2022

    Back to top